n8foo's blog

Butter Beans & Kale

2024-02-16T00:00:00Z

Transcribing a recipe for posterity. I keep telling people this tastes like bacon, and it does!

Butter Beans & Kale

Need

3 tbsp olive oil
¼ tsp ccrushed red pepper flakes
15oz can butter beans, rinsed & drained & patted dry
2 garlic cloves, roughly chopped
1 ½ cups kale, tough stems removed, torn into bite sized pieces
sea salt & ground pepper
1 tsbp fresh lemon juice
fresh parm for serving

Make

Heat oil in a large saucepan over medium heat.
Add red pepper and cook for 30 seconds, stirring often. Add beans, cook 4-5 minutes then flip and cook additional 4-5 minutes.
Stir in garlic, kale, salt & pepper to taste.
Cook until kale wilts ~2 minutes.
Mix in lemon juicce, cook 1 minute longer & all is evenly coated.

Setting up the Vortex Race 3 for Mac

2024-01-08T00:00:00Z

Every year or so, my Vortex Race 3 keyboard seems to reset itsself. Not sure if it's me, or a combo of how my various docks interact w/it, but I find myself stuck on the default layout and having to research how to set it up for a Mac again. For posterity and anyone else having this issue, here's my steps to a Mac user's minimal maintenance setup on the Race 3:

Keys look like this:

[ L1 ][ L2 ][ L3 ][ Space ][ R1 ][ R2 ][ R3 ]

We're going to reset it, swap to a programmable layer, switch to windows mode (it's the least problematic) and then swap the alt and command keys (L2/L3). That's it.

Reset everything by pressing L3+R1 for 5 seconds. Left LED will blink white color while you're holding the keys. Release them after it stopeed blinking.
Get into one of the programmable layers (R2+RShift) – red is fine.
Put the keyboard in Windows Mode (R2+W), it's the least problematic one.
Go into programming mode: Fn+R3 right LED should light up white.
Then hit the L2 then L3, then Pn (LED shines white) to finish first move.
Then hit the L3 then L2, then Pn (LED shines white) to finish 2nd move.
R2+R3 to get out of programming mode (LED goes off).

References:

arogulin for the cheatsheet, modified for my use case.
Race3 Manual
POK3R Manual (for programming)

Date/Time SublimeText Plugin

2023-12-07T00:00:00Z

I keep a daily log in a markdown doc and have been manually typing the day and time in for a few months now. My editor is SublimeText, which supports python plugins so I figured this could be done pretty easily. Here's what I came up with after a few minutes:

In Sublime Text, go to "Tools" > "Developer" > "New Plugin...".
Replace the default code with the following Python script:

import sublime
import sublime_plugin
from datetime import datetime, timezone

class InsertDateTimeCommand(sublime_plugin.TextCommand):
    def run(self, edit, date_or_time):
        if date_or_time == "date":
            content = self.generate_date_string()
        elif date_or_time == "time":
            content = self.generate_time_string()
        else:
            return

        self.insert_content(edit, content)

    def generate_date_string(self):
        now = datetime.now()
        formatted_date = now.strftime("%A %Y-%m-%d")
        return f"{formatted_date}\n{'=' * len(formatted_date)}"

    def generate_time_string(self):
        now = datetime.now(timezone.utc)
        local_time = now.astimezone()
        utc_time = now.strftime("%H:%M:%S UTC")
        local_time_str = local_time.strftime("%I:%M:%S %p %Z")
        return f"{local_time_str} ({utc_time})"

    def insert_content(self, edit, content):
        for region in self.view.sel():
            self.view.insert(edit, region.begin(), content + '\n')

Save the file with somethign like insert_date_time.py in your Sublime Text "Packages" directory.
Now, you can create a key binding to trigger this command. Go to "Preferences" > "Key Bindings" and add a binding similar to the following:

[
    { "keys": ["ctrl+shift+d"], "command": "insert_date_time", "args": {"date_or_time": "date"} },
    { "keys": ["ctrl+shift+t"], "command": "insert_date_time", "args": {"date_or_time": "time"} }
]

Now, when you press ctrl+shift+d, it will insert the current date, and pressing ctrl+shift+t will insert the current time along with UTC time.

Looks like this:

Thursday 2023-12-07
===================

And this:

12:38:05 PM CST (18:38:05 UTC)

Awk Associative Arrays Rule!

2021-11-10T00:00:00Z

Awk associative arrays rule!

file.dat:

foo 234
bar 43
baz 109
bar 823
foo 283
baz 23

awk '{a[$1] += $2} END {for (i in a) print i,a[i]}' file.dat

output:

baz 132
foo 517
bar 866

Now, do this on a file with 100,000 lines.

2019 Total Lunar Eclipse

2019-01-23T00:00:00Z

The Total Lunar Eclipse this past weekend was amazing! I had set up some new photography gear to take pictures and was really looking forward to some great shots. I set up my camera gear, which was a Fuji X-T2 mated to an older Canon FD300mmF4L mounted on an Omegon Mini Track LX2. The Mini Track is a mechanical wind-up motorized equatorial mount for astrophotography.

Unfortunately, the cloud cover was huge. I got a few early shots just after the partial started and then the clouds took over. It wasn't until 2 hours later I noticed a break in the clouds headed our way.

YES!

And there it was! So pretty! Really incredible, and am I seeing purple? Definitely my favorite shot of the 100 or so I took.

The clouds were clear for a few moments, so I dragged both my sleeping kids out of their warm bed into the 20 degree night to show them the sky. Neither of them cared and only wanted to go back inside. Youth!

Clouds started to come back in so I got a few wide angle shots to capture the beauty of the night sky during the total.

I also shot some bracketed exposures and spent a few hours aligning and processing to produce this detailed image.

I took a ton of shots. I think the mini track really helped as I didn't have to worry about lengthy exposure times with the longer lens. And I didn't have to move the camera every couple minutes. It's going to be a great addition to my astrophotography setup.

My gallery of shots here.

3D Printed Xmas Tree Ornaments...of your house!

2018-12-23T00:00:00Z

A few weeks ago, I made a model of our house in 3D. We've been discussing a home remodel project and I've been trying to get better at CAD...so it seemed like a useful way to learn a bit more. I fired up my software of choice (OpenSCAD), did a bunch of measuring, and modeled out an accurate scale representation of our humble abode. I made functions for everything: a building with a gable roof, gabled dormers, shed porch, chimney, etc. After I was satisfied with the accuracy, I sat down to show the rendering to my wife so we could discuss the remodel. And, just for fun, I had printed up the result (in PLA at 150 microns). It was 1mm for each foot which made it 304:1 scale.

Her first comment:

"This would be a great Christmas tree ornament! Hey, you should make these for our family this year! Maybe paint them and put snow on the roof too?"

Now, that's a fantastic idea! Never done anything like this before! That week I picked up some modeling paint, some fake snow for the roof, and some tiny hooks.

Modeling

At home, I was able to quickly go outside with a measuring tape and get all the dimensions I'd need. But some of my family lives 2000+ miles away, and I didn't want to give it away by asking questions. However, most property tax records are public and many of them include building dimensions. I was able to look up all my relatives but one. Looked like this:

One of my brothers didn't have a sophisticated county website with dimensions, but I was able to find basic dimensions from his deed and used pictures and views from Google maps to approximate the rest.

I had to write some more modules for bay windows, decks, porches with decks, porches with columns, etc - and after that was done it only took me about 30-45 min per house to do the modeling. I'd say I spent an hour per night on it, for about a week.

Once I had the CAD done, I got to printing. Printed in PLA at 150 microns on my Prusa MK2S. Some of the models needed tweaking, the columns didn't work, or I got updated info on dimensions..."Hey, did your tree touch the ceiling this year? Nice one, Griswold. So....how tall was that?" etc.

Finishing

After the models were printed, I sat down one Saturday afternoon, and got to work. The most uncertain part of this project was determining where the center of gravity would be for the hook, so they would hang straight on the tree. Houses are not especially symmetrical, one was even shaped like a U! I used some sharp tools and grabbed the little houses by the edges to get a rough idea and then just kinda winged it. Tested my method out on one of the early non-usable prints I made - drilled a tiny hole with the drill and tested it out - nailed it! I was able to get them all close enough that balance could be adjusted with a little bit of angle on the screw-in hook.

Painting is't something I'm good at or have done much of, but gotta start somewhere. Unscrewed the hooks and got out the paints. I chose gold, with white accents and a red front door. It seemed Christmas-y to me. 2 coats of paint were needed, the print layers seemed to absorb the paint. It was painstaking work and I felt like I was going to go blind, but they looked pretty great in the end. Painting the red front door was hard and took forever, but worth it! As I finished up, I made a mistake with white paint near a roofline...but realized it looked like an icicle. So, I added little icicles to them all, super cute looking.

The snow I had ordered was made from crushed glass - and I tested it out on a test house - I coated the roof of the house with glue and poured it on. Wow! It was really beautiful and sparkly...but the bits were too big. Didn't look like snow. So, I just used some white glitter instead and it looked much more realistic.

Boy they look good! The gold paint is shiny!

Packaging

I was struggling to figure out what to put these neat little ornaments in...cardboard boxes were all way too big and weren't nice enough - so at the last minute I decided to design and print a clear box, so they'd have something to store them in each year. And made it oddly shaped while I was at it, because why not!

I mailed 2 of them off and gave the rest out at family xmas a few days later. They were a hit! Check out the pics of them on the tree!

Merry Christmas!

3D Printing Plumbing Tools

2018-02-17T00:00:00Z

This weekend, I was doing a little kitchen faucet replacement and ran into some trouble removing the old Moen hardware. Moen faucets come with this install tool that's similar to a thin-wall deep socket but longer, thinner, and completely hollow. And, I’ve learned if you don’t have the tool, it’s neary impossible to remove the faucet without damaging the sink. Especially when it's 20 years old and corroded like the one I'm removing. Earlier this week, I had tried in vain to remove it without the tool...and ended up at Home Depot advicing with the plumbing dude, who sold me a tool that would definitely do the trick. Fast forward to today, I have the sink tore apart, discovered the HD basin wrench is hopeless for the Moen faucet, and realized the only way to remove this thing is to buy a $17 plastic tool from Moen (part # 118305)...that I’ll never use again. It looks like one of these, my faucet probably came with top right:

This tool is not available anywhere locally. The fastest I could get it here is next week, which means I have to reassemble everything so the family can use the kitchen in the mean time. I confessed to my wife the situation I'd created, and was considering drastic measures aka. brute force, without the tool (miserable). She asked what the Moen tool looked like - when I told her it was a plastic tool, she said "Plastic? Why don't you just print one?" Damn, I wish I'd thought of that earlier! 😍

So, set to work immediatly to make my own. I did some measuring & designed one in OpenSCAD. Mine has a 1/2 socket in the bottom for a wrench and knobs to turn it by hand. It should slip right over the nut and twist it off...if it's strong enough. Here's what my Moen tool looks like:

Here it is ready for printing:

I printed it in black PLA, at 100% infill with a 0.35mm layer height...it took about an hour and cost me 65 cents in material. Here is a video of it printing, if you're so inclined. And here it is going to work:

At this point, I just assumed that the first twist would snap something. But instead...

SUCCESS!

I can't believe it worked...I had read about other folks actually breaking the plastic Moen tool so I was skeptical it would hold up to the stress of a corroded & rusted nut. How I was wrong...I squeezed the hell out of it with vice grips and torqued on it hard with a socket wrench. Right out of the gate I turned it the wrong direction a whole turn before I realized it - if it was ever gonna break, it would have broken then. It's got serious battle scars but performed flawlessly!

If you find this useful, I've uploaded the files here and also to Thingiverse. If you're searching the web for this exact problem and don't have a 3D printer, let me know and I'll mail you my used 3D-printed tool. It's still good! 😎

P.S. New Hotness:

Automating GMail

2018-02-11T00:00:00Z

Automating GMail cleanup tasks turned out to be a great time saver for me. I get a lot of mail from automated processes I need to see, but don't need to keep for long. One example is monitoring alerts, another is admin/root type emails. Yet another is email notifications from services like NextDoor, YouTube, Google Calendar, etc. I get a ton of these and I just don't need to reference them beyond a few days. Part of my weekly (sometimes daily) routine included cleaning these up. At best, a 30 second interruption. At worst, kill my email for half an hour with the dreaded "Temporary Error". So, I wrote a little script to do this for me automatically, based on labels. Now I just read & archive them (or whatever) and the script does the rest. No more cleanups and my mailbox is far more tolerable for searching.

My script is below. Follow the instructions on the GMail page here and paste the content of my script instead. Name it 'Email Cleanup' or something like that. You'll need to update the labels to match the labels you want to use to clean up.

var days31 = ["label1",
              "label2",
              "label3"];
var days7 =  ["label4",
              "label5",
              "label6",
              "label7"];


function auto_delete_mail(userLabel,days) {
  var label = GmailApp.getUserLabelByName(userLabel);
  if(label == null){
    GmailApp.createLabel(userLabel);
  }
  else{
    var delayDays = days // Enter # of days before messages are moved to trash
    var maxDate = new Date();
    maxDate.setDate(maxDate.getDate()-delayDays);
    var threads = label.getThreads();
    for (var i = 0; i < threads.length; i++) {
      if (threads[i].getLastMessageDate()<maxDate){
        threads[i].moveToTrash();
      }
    }
  }
}

days31.forEach( function(s) {
     auto_delete_mail(s,"31")
} );

days7.forEach( function(s) {
     auto_delete_mail(s,"7")
} );

I've also posted it on Github, if you see changes I should make, send me a pull request!

Set Vim as the default editor

2017-01-28T00:00:00Z

It just kills me when I type git commit or some other such command on a newly configured machine and up comes nano or (worse!) pico. And, I so infrequently have to do this that I can never remember it - so, for posterity:

To set your default editor (to Vim) on Ubuntu:

update-alternatives --config editor

Ex:

$ sudo update-alternatives --config editor
There are 4 choices for the alternative editor (providing /usr/bin/editor).

  Selection    Path                Priority   Status
-----------------------------------------------------------
  0            /bin/nano            40        auto mode
  1            /bin/ed             -100       manual mode
  2            /bin/nano            40        manual mode
* 3            /usr/bin/vim.basic   30        manual mode
  4            /usr/bin/vim.tiny    10        manual mode

Press <enter> to keep the current choice[*], or type selection number: 3

Uncomplicated FireWall (UFW) on Ubuntu

2017-01-16T00:00:00Z

UFW is a pretty simple to use firewall wrapper for Ubuntu. Recently, I have been using it to block spammers on a little service I run for the Nashville Tech community. I used to do this with iptables directly, but this is far simpler.

Here's a quick primer on firing it up and blocking a particular IP address. It's disabled by default so you need to allow your services and then turn it on:

ufw allow ssh/tcp
ufw allow 80/tcp
ufw logging on
ufw enable
ufw status

Order matters - once a rule is matched the others will not be evaluated. So, to block that IP, you need to insert it early:

ufw insert 1 deny from 16.16.9.0/24

Here's what these rules look like:

# ufw status
Status: active

To                         Action      From
--                         ------      ----
Anywhere                   DENY        16.16.9.0/24             
22/tcp                     ALLOW       Anywhere                  
80/tcp                     ALLOW       Anywhere                  
22/tcp (v6)                ALLOW       Anywhere (v6)             
80/tcp (v6)                ALLOW       Anywhere (v6)

And you can number the output to make it easy to clean up or delete your rules:

# ufw status numbered
Status: active

     To                         Action      From
     --                         ------      ----
[ 1] Anywhere                   DENY IN     16.16.9.0/24             
[ 2] 22/tcp                     ALLOW IN    Anywhere                  
[ 3] 80/tcp                     ALLOW IN    Anywhere                  
[ 4] 22/tcp (v6)                ALLOW IN    Anywhere (v6)             
[ 5] 80/tcp (v6)                ALLOW IN    Anywhere (v6)

To delete one it'd be ex: ufw delete 1

2017 Resolutions

2017-01-04T00:00:00Z

I came up with a few new years resolutions. In no particular order:

write more (this website)
use a journal
organize my personal websites and their data. this is tricky, I have a few decades of web cruft.
organize photos as they are taken
spend a little time each day organizing my old photos. I also have a few decades of photos to organize.
find creative ways to spend time with my kids that expand their minds and keep me youthful.
go to bed earlier ; get up earlier. I'm a natural night-owl so this may be more of a short-lived experiment.

Happy Solstice!

2016-12-21T00:00:00Z

The image below is an example of solargraphy. A pinhole camera is used to take a picture over 6 months. This photography technique perfectly illustrates the position of the sun between the summer and winter solstice.

Skylight Simulation

2016-05-07T00:00:00Z

Trying to decide where to place some skylights in my garage renovation project, I needed to simluate the look. I took pictures of the one installed skylight from the perspective of the camera if it was installed in 2 places, and splicing them into a 'blank' image. Result:

and

I decided to go with #2. Aside from the exposure and the skylight being open, very accurate!

Code & Pinot: UNIX!

2015-04-23T00:00:00Z

I gave a presentation tonight at Nashville Girl Geek Dinner's Code & Pinot event. We went over some UNIX history and did a bit of command line intro. Action shot:

It was a great event! I had a lot of fun teaching something I'm passionate about (while de-rusting a bit on relating the basics!) and had some great conversation afterwards. I've given the history talk a number of times over the years, but the GGD Nashville crew got to experience my first test of this talk with slides! \o/ You can download my history presentation here. And here is the history of what I typed during the UNIX lesson.

Side note: We discussed the historically famous "Space Travel" game (look it up). But, all I knew was that it was a game...and I'm not a gamer. So, I had to look it up a bit more when I got home. Apparently it let you simulate travel between planets in our solar system and cost about $50-$75 in 1969 money to play a round on the GE 645 running MULTICS! Which is $320-$482 in 2015 money. No wonder re-writing the whole OS on cheaper hardware was worth it. :-P

If any of you were there and would like to know more, here are some good links that I used when re-acquainting myself with UNIX's colorful history and some beginner material:

More History of UNIX http://www.albion.com/security/intro-2.html http://web.mit.edu/saltzer/www/multics.html http://en.wikipedia.org/wiki/History_of_Unix http://en.wikipedia.org/wiki/Unix

Other Good Intros http://freeengineer.org/learnUNIXin10minutes.html http://cli.learncodethehardway.org/book/

Don’t have UNIX to play with? Get it in the browser with JS/UIX! http://www.masswerk.at/jsuix/

Cheat Sheets http://files.fosswire.com/2007/08/fwunixref.pdf http://sites.tufts.edu/cbi/files/2013/01/linux_cheat_sheet.pdf

Beers w/Trey

2013-05-08T00:00:00Z

Trey came to town. So, we had beer. And I made picturefilms. Used a GoPro and the Radian, which had arrived a few days before. Still not great with it, but the results here were fun. Filmed at both Craft Brewed and M.L. Rose. Approximately 250X normal speed.

Thoughts on "negative-Kelvin"

2013-01-05T00:00:00Z

Nature: Quantum gas goes below absolute zero.

I thought I had a decent understanding of physics. But after reading this, someone should revoke my 'amateur scientist' card. This (from Wikipedia) helped me understand it:

Since we started with over half the atoms in the spin-down state, initially this drives the system towards a 50/50 mixture, so the entropy is increasing, corresponding to a positive temperature. However, at some point more than half of the spins are in the spin-up position. In this case, adding additional energy reduces the entropy, since it moves the system further from a 50/50 mixture. This reduction in entropy with the addition of energy corresponds to a negative temperature.

This is not about the common notions of hot and cold, this is thermodynamic temperature, which is about entropy and energy. OK, so to me, this amounts to a neat physics trick. The universe will not collapse and our understanding of physics hasn't changed. Hopefully, it'll inspire a few folks (like me) to understand it better. Doing more reading, it reads like this only works in a 'system' of atoms, not with a singular atom. If you can't make a single atom colder than 0.0 kelvin, then the fundamental physics models don't change. Somewhat frustratingly, I see no mentions of anti-gravity, which was the most radical thing said on the nature.com article. So, please erase that and any anti-gravity belt predictions from your memory banks.

Speaking of theoretical maximums, another fascinating one is the concept of "absolute hot", which is currently defined as the Planck temperature, (1.416785×10^32^ kelvin). All physics models break down, even things like gravity. And, theory says that the entire universe has already experienced this temperature, a fraction of a second after the big bang. Enjoy that thought.

High-Speed Datacenter Work

2012-11-08T00:00:00Z

Went to the datacenter last night to build out a few DB servers with 64GB of RAM. And set up a timelapse to record parts of the work. Marc, Brian and I did 2 servers each. You can see some up-close shots of the Dell R710 hardware, though it's quite blurry. Playback is 74 x normal speed.

Wasp Nest

2012-11-01T00:00:00Z

Found a paper wasp nest today while we were having work done on the house. It was cold out and I thought they were dead...when I set it down in the sun to take a picture, I saw some movement. So, I filmed the little guy trying to get out. National Geographic here I come.

Rain Math

2012-09-30T00:00:00Z

The storm headed our way tonight is predicted to drop 2" of rain over Nashville. If it covers the entire 527 square miles with that amount (on average), that storm would drop 152.8 billion pounds of water. Yay science.

Here's my math:

1 inch of rain x 1 square mile = 65,785 cubic meters = 17,378,742 gallons

Nashville is 527 square miles according to Wikipedia.

A gallon of water weighs 8.35 lb.

So, 2 inches of rain over every inch of Nashville is 2 x 527 x 17,378,742 ....

Which is 18,317,194,068 gallons. Which weighs = 152,948,570,467 lb.

Yikes. I better go start mowing the yard like right now. I don't want to get killed when the rain falls on me

git + sudo + local ssh keys

2012-05-08T00:00:00Z

Some colleagues and I wanted to be able to check out code onto a remote server using our local github ssh keys. And we should be able to do that as any user we please (for example, the deploy user). After a bit of research, I found that it's possible! In short, you use ssh-agent to pass your key credentials on to the remote server and set up sudo to pass those credentials along thru the environments. Let's do this!

I'm on a Mac, which has ssh-agent running by default. Yay! But, you still want to verify that your key is added to the agent:

laptop:~ n8foo$ ssh-add -l
2048 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
/Users/n8foo/.ssh/id_rsa (RSA)

Now, ssh into your remote server using the -A flag to ssh to pass auth along.

ssh -A remoteuser@remote.server.com

Test that ssh's agent auth worked:

[remoteuser@remote ~]$ ssh-add -l
2048 00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
/Users/n8foo/.ssh/id_rsa (RSA)

Your keys should show up. Now, confirm that you can access github with your key from that remote server:

[remoteuser@remote ~]$ ssh -T git@github.com

Hi n8foo! You've successfully authenticated, but GitHub does not provide shell access.

OK, now let's enable this so we can switch users with sudo. Sudo needs to pass the SSH_AUTH_SOCK environment variable on through. To do that, add (or modify) the defaults line in /etc/sudoers to look something like this:

Defaults env_keep+=SSH_AUTH_SOCK

You can do this, if you have a default ubuntu sudo config:

# sed -i "s/^Defaults.*/Defaults env_keep+=SSH_AUTH_SOCK/g"
/etc/sudoers

Everything should be working now. Let's test...

[remoteuser@remote ~]$ sudo su - someotheruser
[someotheruser@remote ~]$ ssh -T git@github.com

Hi n8foo! You've successfully authenticated, but GitHub does not provide shell access.

You can now get your git on, directly on your remote machine, as another user. Done!

BCN11 Wrap-Up

2011-10-16T00:00:00Z

My Space Balloon presentation at BarCamp Nashville went well. I normally would 'wing' a BarCamp talk, showing only the pics/video or show-n-tell. But I realized earlier in the week that I had a lot to cover and only 35 minutes to complete it. I figured some organization of my material might be in order. So, those of you that were there got to witness my first ever keynote presentation. Woo hoo!

I had a number of people tell me that they missed it, due to collision with blocked-off roads from a footrace that morning or the 9AM timeslot. So, here is the presentation in PDF format, with movies removed: Space Balloon BCN11 Presentation. If you want to see the movies, they are linked on my blog here.

One other really cool thing that happened yesterday during the talk was Nick Navatta drawing a graphic of the presentation. Seriously cool. He even let me keep the end result, which I shot and put up on flickr.

Here is the full pic:

Nashville Amazon Web Services User Group

2011-09-15T00:00:00Z

A few of us are putting together a local Amazon Web Services User Group here in Nashville. The initial idea is to follow a format similar to Portland's AWSUG. Invite local experts, give talks, get together and share stories, etc. Maybe host a yearly event in Nashville, not sure. These are all just ideas at the moment. AWS's most game-changing (and also complex) product is EC2 and I'm guessing that will garner a lot of interest. That's also my area of expertise and interest.

Scheduled for Wednesday, Sept 28th (2 weeks from yesterday), the first meet up would be an informal get together to come up with a simple charter, brainstorm on activities, come up with a list of potential venues and sketch out a general calendar for the next quarter. I figure this can be accomplished after work, across a table of drinks. Yeah?

If you'd like to join....we'll be at the Corsair Taproom from 6pm till about 8pm.

Nashville Amazon Web Services User Group (NAWSUG)
Initial Planning Meeting - Informal w/beer
Sept 28th 2011, 6pm-8pm at the Corsair Taproom

Corsair Taproom Location:
1200 Clinton Street #110
Nashville, TN 37203
615-321-9109
Map Link

BarCamp 0b10

2011-09-13T00:00:00Z

There's been a flurry of activity in Nashville about Bar Camp over the last 48 hours...and 5 years. I won't summarize because it removes the passion. If you care, go read them (referenced at the bottom).

So what do we (the Nashville community) do about it. Well, we act. Earlier today Tim Moses posted this:

I think there is room for an alternate BarCamp that answers your concerns without conflicting with the current BarCamp. BCN may not be true BarCamp format, but it is successful. It may not be tech-heavy, but that seems to be improving in large part by the BCN organizers. Making dramatic changes to BCN would most likely hurt it more than help.

The problem isn't with the existence of BCN or how it operates, but the nonexistence of a tech-focused BarCamp. Many BCN supporters have repeatedly suggested an alternate, but no one has stepped up to do it.

On that note, Nathan Hubbard (ex-Telalinker with true BarCamp experience), and I are organizing BarCamp 0b10, a tech-focused, 2 day, traditional BarCamp to complement BCN. The current plan is to space it far enough from BCN (maybe Spring) to not force a choice between the two. If you like both, go to both, present at both. If not, pick your BarCamp of choice.

We're shooting for a date sometime this spring and looking to things like this and people like this for inspiration and guidance. Initial thoughts are: traditional BarCamp, 2 days (camping!), complimentary to BCN, 'tech focused' but not tech only, simpler and less complex, less organized, etc. Tim and I will announce more via this blog and our twitter accounts (@timmoses, @n8foo) in the next few months. Keep your eyes peeled. Update: we have a new twitter account: @BarCamp0b10 and hashtag #0b10.

Right now, the Nashville community needs to focus on making BarCamp Nashville 2011 awesome. Go sign up. Go to make a difference. Go to see what it's like if you've never been. Don't wait on our event, go act.

References:

Nashville Scene: BarCampNashville Descends Into Online BarFightNashville
Chris Wage: The Not-So-Great Barcamp Schism
Matt George: Clarification on BCN comments
Twitter: BCN_Critic
Countless posts on twitter by the Nashville BCN crew and other tech heavyweights.
Bar Camp Nashville
The Rules of BarCamp
BarCampSD

Space Balloon Post Launch Wrapup

2011-09-12T00:00:00Z

SPACE

The image above is a picture taken at 102,000 feet over Nashville back in April, from our Space Balloon.

Yep, the balloon launch back in April was a success. As was the presentation that Marc, Jared and I did at Emma Talent Night. It was actually far better than I could have imagined. We kept the whole project a secret right up until the night of the show. For weeks, people were watching us tossing parachutes out windows and messing with flashing lights and cameras. It really built up some great suspense. By the time the night finally arrived for the big reveal of our 'talent', the audience was actually chanting "SPACE! SPACE! SPACE! SPACE!". It was epic, really, for a bunch of nerds to get up and talk about sending a balloon to space in the middle of 2 dozen other awesome music, singing, magic and other acts. And get cheered at during the process. While drinking. Truly one of the most awesome things I've ever done.

Enough gushing, down to the data.

This data was recorded by our flight computer, an on board micro Arduino with 2 different sets of 1-Wire temp and barometric sensors and a 3-way gyro.

Avg ascent rate: 4.89 m/s (10.9 mph)
Avg ascent rate first hour: 2.32 m/s (5.19 mph)
min temperature : -59.116 F
max altitude : 102,496 ft (19.4 mi)
min air pressure : 930pa (0.93% surface)
max descent rate : 245 mph

-59 F! Wooo wee that's cold! The 245 mph speed was with the chute open! See, the air is so thin up there that even with the chute open it was screaming towards earth. At more reasonable altitudes, it slowed down to a more lazy pace of 15 mph. The height we achieved was 102.5K feet. That's almost 20 miles! One of our other calculations shows 106k feet so it was in that range somewhere.

On to the videos and pictures:

This is what we showed at the talent show after we got up and gave our talk about the balloon, more of a quick documentary of the process. It always makes me laugh watching our first two parachute drop tests. Especially on the second one when Pamela laughs at us. Music courtesy of 84001 (my co-worker Jimmy's band).

This is the music video I put together for 84001, to be shown while they played live music on stage. It's various trippy time lapse and spacey stuff and about 10 minutes of balloon footage that starts around the 2:20 mark and the burst occurs at around 7:10...the music in this video is basically the same set they played live. The 3 cameras in the balloon filmed a total of 8GB of data across 3.5 hours, of which you are seeing less than 2% here:

More pictures, on Flickr with some video as well:http://www.flickr.com/photos/n8foo/sets/72157625894886863/
The actual slideshow, complete with graphs and stuff, from the Presenation: http://www.youtube.com/watch?v=R_aiON0-2J8

Thanks to Marc and Jared for making this a super kick ass fun science project. I can't wait for the next one. :-)

tcpdump web traffic

2011-07-12T00:00:00Z

Want to tcpdump your web traffic for debugging? Here's the formula I've been using lately:

tcpdump -s 1514 -Ai en0 'tcp port 80 and tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x47455420'

Reddit Traffic

2011-02-23T00:00:00Z

This is what it looks like when someone posts a link to your blog on reddit (linux subreddit). I went from 48 visits the previous day to 581 visits the day of the reddit post. More than an order of magnitude more visitors. I don't give a s**t about visitor count but as a graph and chart nerd, it's neat to see in the google analytics.

Side note: great discussion on reddit. I will be making a followup article about pgp + vim, since that seems pretty slick. The jury is still out on which is a better solution for me.

encrypted password vault with Vim + openssl

2011-02-21T00:00:00Z

In a post last year, DIY Encrypted Password Vault, I showed a simple way to use OpenSSL to create encrypted text files. Since I'd need to de-crypt those files to edit them (usually with Vim) there would be an unencrypted temp file sitting around while I was editing. And using a filesystem with history meant they were around for a long time. BAD. Surely there is a better way...

Can we encrypt directly with Vim? Actually, yes...Vim has encryption built in (via the -x flag)...it works and it's simple. Problem is that it uses 'crypt', which is not terribly hard to break. Also, it leaves a cleartext .tmp file around while you're editing it. Which means it's worthless to me for a password safe.

Enter the VIM openssl plugin. This plugin will allow you to write files with particular extensions corresponding to the type of encryption you desire (ex: ..des3 .aes .bf .bfa .idea .cast .rc2 .rc4 .rc5) and it turns off the swap file and .viminfo log, leaving no tmp files around. Excellent! Here's typical usage:

Edit a new file with the .bfa extension:

$ vi test.bfa

Add your secrets and save it out. It will prompt you for a password (twice) to encrypt against.

blah blah blah : secrets of the world  
~  
~  
~  
~  
:wq  
enter bf-cbc encryption password:  
Verifying - enter bf-cbc encryption password:

You can look at the data in the file to see the encrypted content:

$ cat test.bfa  
U2FsdGVkX1+TPJBn3hsJ6nzsXzDvTXOxdDk1PkWkTDFG45HIvMnZbBNIrnJubPCY  
EexmfIJpZqo=

To re-open a previously encrypted file, just open it with vi. The plugin automatically recognizes the extension and prompts for your password:

"test.bfa" 2L, 78C

enter bf-cbc decryption password:

Pretty slick! You'll need the openssl binary in your path for this to work, which is pretty standard these days. Here is a little script that I run to set this up on my various home directories:

#! /bin/sh

test -d ~/.vim || mkdir ~/.vim/  
test -d ~/.vim/plugin || mkdir ~/.vim/plugin  
curl "http://www.vim.org/scripts/download_script.php?src_id=8564"
> ~/.vim/plugin/openssl.vim

Edit: 2010+ versions of Vim have blowfish support. Excellent, forward progress! I'm probably not going to upgrade Vim on my Mac and all my servers just for this when a plugin can work. Good to see progress but for now, this makes the most sense for me.

Space Balloon One

2011-02-12T00:00:00Z

My friend Marc and I started doing research on what it would take to send a balloon to 'near space'. We've been inspired by a few others, most recently the father-son team from the UK that sent an iPhone up to 100,000 feet. We think we can build this for under $200, probably less.

Things we know:

4 lb or larger payload requires FAA approval
GPS ceiling limit is 11 miles
Temps are -70F
Winds are 150MPH
good chance of a water/wet landing
single balloon

The first launch will be to test the concepts and recovery mechanism. We have planned to use the instamapper service in combination with a t-mobile phone for ground tracking. We have a camera that would do the trick for the image capturing, using CHDK. Our friend has donated a cryogenic styrofoam box that should help with insulation and we can use hot-packs to keep it warm in there. Need some sort of LED light to help us in recovery after dusk.

We're also considering building a small data tracking device, for recording temperature, light and pressure. Maybe some other environmentals, not sure. Probably arduino powered, since that seems pretty easy and cheap.

Questions we have right now:

how do we track it over 11 miles?
what kind of balloon do I use?
how do we deploy the parachute?
what are we missing?

Would love to see some comments by fellow space nerds.

2010 Camera Advice

2010-12-10T00:00:00Z

From some advice for a friend, looking to travel around the world, asking about cameras for travel.

I always say 'you should by a DSLR', as it's a quantum leap in abilities. The huge resulting change in your photos is worth it. Just know you that it's bulk may mean you don't have it out all the time, even unconsciously. Most likely, if you get one now, you'll carry it everywhere for at least some time and the pictures you'll have the rest of your life will be worth it.

From my own travel experiences: When you're walking around with a big camera and glass around your neck, the weight and size get to be a burden. So does the "I have an expensive camera" factor. I took my DSLR and a powershot with me on my moto trip...ended up using the powershot for 95% of the shots for those reasons. It was a cheaper cam too, so I would take equipment-risky shots...I dropped it a handful of times where my DSLR would have shattered and would hand it to anyone willing to take a shot. (http://www.flickr.com/photos/n8foo/3597617054/) There is also something to be said for having a camera that's easy to 'wear' all day and have ready to fire. With my DSLR setup, I find myself asking 'is this shot worth getting this thing back out?' all the time...and I miss opportunities due to it. Which means, instead of in my sling bag, I carry it around my neck/in my hands constantly, and we're back to the top of this paragraph. I have long considered picking up a G11 (G12 out now w/better low light) as my travel camera for these reasons.

Back to the DSLR - Assuming Canon 550D, I'd look at 3 lenses. The EF-S 18-200 IS, kick ass walkabout lens, I used it on my 7D when I don't know what kind of photos to expect (travel). 11x equivalent zoom so you can get wide shots and then zoom in on that wildlife off in the distance. The EF-S 17-55 2.8 IS is amazing. Nearly all my best shots have been taken with it. It's got L glass but isn't designated L due to the EF-S lineup. Downside is that it's kinda big. If you want that awesome DOF, pick up a Canon 50mm f/1.8 for $99...it's cheap plastic but will take good low light portraits. I personally opted for the Sigma 30mm 1.4 for my fast prime lens, but it was 4x the price.

Micro 4/3 has no viewfinder, suck. It's avail as a sep. accessory on most but then you're about as bulky as a DSLR. The E-P2 is the best of the breed of 4/3 so you can't really go wrong if you do go down that road. I'd be jealous of it. :-) I played with a Sony NEX-5 tonight at Target and I hated it's ergos and electronic focus ring. Shots looked pretty tho. If you're looking seriously at the 4/3 stuff, check the Canon G11/G12, those are amazing cams and have good ergos. The f/2.8 is plenty for low light, coupled with the IS and kick butt sensor (12800 ISO!).

Re: DOF - if you want more DOF, get further away from your subject and use the zoom. It tends to flatten the image but the DOF will be more dramatic than at closer ranges. You probably already know this.

One last comment: one of the best things you can get to make your photography better is a tripod or even a monopod. It'll make you compose your shots, makes them sharper and lets you leave the shutter open longer then 1/30th.

No matter what gear you buy, 'getting better at photography' is the right path.

network gear config management with tftpd and subversion

2010-03-18T00:00:00Z

Keeping revisions and history on device configs is an essential part of a good change control process. I've found this to be an extremely useful and ass-saving part of system/network administration.

WARNING: Consider the security ramifications before you start a project like this. Access to network configs saved on a filesystem or code repository can reveal network topology and login information (some network gear passwords are easily decrypted). Be careful how and where you store this data. For my environment, the tftp server and SVN repository have restricted access to only the systems team.

Here's how I do it:

tftpd server reachable from switch management network
subversion repository for switch configs
manually saving switch configs to the tftpd server
cron'd script to automatically check in switch configs (if I don't do it myself)

Setting up TFTPd is pretty easy. On Ubuntu/Debian, it's simple:

apt-get install xinetd tftpd tftp

Set up something like this in /etc/xinetd.d:

service tftp {  
protocol = udp  
port = 69  
socket_type = dgram  
wait = yes  
user = nobody  
server = /usr/sbin/in.tftpd  
server_args = /tftpboot  
disable = no  
}

Set up the various directories and start the daemon. Be sure of your permissions, as your switch configs will be written to these directories.

mkdir -p /tftpboot/netconfigs/  
chmod -R 700 /tftpboot  
chown -R nobody /tftpboot  
/etc/init.d/xinetd start

Double check that you can write switch configs out using your network gear. This is what it looks like on a Cisco 3560:

copy system:/running-config tftp://TFTPHOST:/netconfigs/SWITCH.config

And on a Cisco PIX firewall:

wr net TFTPHOST:netconfigs/SWITCH.config

Now you need to automate this. I created a utility user on each switch and a utility user in my subversion repository. This is what my tftp_switch.sh script looks like for my Cisco 3560's:

#!/bin/sh

DATE=\`date +%F\`SWITCHES='sw-1 sw-2 sw-3 sw-4 sw-5'  
USER=username  
PASS=password  
TFTPHOST="TFTPHOST"

for SWITCH in $SWITCHES  
do  
(echo "${USER}"  
sleep 1  
echo "${PASS}"  
sleep 1  
echo "copy system:/running-config
tftp://${TFTPHOST}://netconfigs/${SWITCH}.config"  
sleep 15  
echo "exit"  
sleep 2  
echo exit  
while read cmd  
do  
echo $cmd  
done) | telnet $SWITCH >> ~/cronlogs/${SWITCH}.${DATE}.log  
done

The 'sleep 15' is there in case it takes a moment to write to the tftp server.

I set up another script that runs the actions above, moves the files into the correct subversion tree, scrubs the files for strings that change too much (like timestamps or what-not) and then checks them into SVN. Here's my example:

#! /bin/sh

# write out network configs to TFTP server  
/root/bin/tftp_switch.sh >/dev/null 2>&amp;1

# copy them into the SVN tree  
cp -fv /tftpboot/netconfigs/*.config /root/svn/network/

# remove things that change all the time  
sed -i "s/ntp clock-period.*/ntp clock-period/g"
/root/svn/network/sw-*.config  
sed -i "s/Written by.*/Written by/g" /root/svn/network/sw-*.config

# check them in with subversion  
cd /root/svn/network ; \\  
svn add -q *.config ; \\  
svn commit -q -m 'automatic checkin'

I set these files owned by root, mode 500 and set it to run nightly in cron.

Since everything is now stored within SVN, I can checkout and in configs, see who and when they were saved (depending on if your gear writes that in the output) and compare to previous versions. I run WebSVN on my repo so it's very easy to see what has changed. Super useful.

If anyone implements this and has suggestions for change, please let me know!

Ruby on Rails dev environment on a remote server

2009-12-25T00:00:00Z

A friend asks:

...so I'm trying to install RoR on a remote server of mine, but it seems that RoR development methodology wants you to test your webpages on localhost:3000. But, obviously, since the computer is in the cloud, I can't just well pull up a webpage on the console. Is there an easy way to get development pages to show up on a web browser that's not local?

So there are a couple of options.

use mod_passenger w/Apache for all your environments. This requires quite a bit more work but it's the way you'd want to do it for any larger environment. Google will teach you all you want about this, but I recommend it only when your environments are mature and you are needing to scale out production.
Tell Apache to pass http://dev.yourdomain.com/ to localhost port 3000. You'd need to set up a dev hostname in DNS and point it at the server as well. It would look like this in the apache config:

<VirtualHost *:80>  
ServerAdmin webmaster@domain.com  
ServerName dev.domain.com  
ProxyPreserveHost On  
ProxyPass / http://127.0.0.1:3000/  
ProxyPassReverse / http://127.0.0.1:3000/  
</VirtualHost>

Similar as above, but if you don't want to mess with DNS, you can
proxy based on the URL:

ProxyPass /foo http://127.0.0.1:3000  
ProxyPassReverse /foo http://127.0.0.1:3000

more on mod_proxy here: http://httpd.apache.org/docs/2.0/mod/mod_proxy.html

Use ssh to tunnel requests from your local machine out to the server (ssh tunnel). ssh will forward the tcp packets across the pipe towards a host you specify on the other end. In this case, you'd tell it to send localhost port 3000 (on your laptop) across the pipe and out to localhost port 3000 on the server. This will only provide access for you (since it's a private tunnel).
```
ssh -L 3000:127.0.0.1:3000 host.server.com
```

Then in your browser surf to http://127.0.0.1:3000

For speed, I'd probably do the last option to test that things are working and go up towards #1 as you get your environment more set up. #1 is the most amount of work (mod_passenger can be a PITA).

wildcard subdomain SSL certs

2009-12-22T00:00:00Z

A friend asked:

If I bought a wildcard certificate for .domain.com, wouldn't that cover .sub.domain.com?

Hrm...I had to look that one up. The answer is: no, not accorindg to the RFC. RFC 2818 states:

Matching is performed using the matching rules specified by [RFC2459]. If more than one identity of a given type is present in the certificate (e.g., more than one dNSName name, a match in any one of the set is considered acceptable.) Names may contain the wildcard character which is considered to match any single domain name component or component fragment. E.g., \.a.com matches foo.a.com but not bar.foo.a.com. f*.com matches foo.com but not bar.com.

more here: http://www.ietf.org/rfc/rfc2818.txt

There are reports that older versions of Firefox don't complain when encountering an out of spec sub-domain SSL wild-card but IE would. I would recommending sticking with the RFC spec.

System Administration with Capistrano

2009-11-25T00:00:00Z

In previous years, when I had to run commands on hundreds or thousands of servers, I'd hack together a combo of expect and perl. It would almost always evolve into a system of complicated config and command files that was rickety and didn't handle errors well. I didn't dare mess with multi-threaded perl, which meant it was serial execution and slow for large clusters. It got the job done but left me wishing for a better system. I have always had cfengine in my sysadmin toolbox, but it's more about entropy reduction and not set up for one-off or occasional situations. I tried a few parallel shell implementations (such as dsh, pdsh) and found them all lacking.

Enter Capistrano. It bills its self as an 'easy deployment' system, with Ruby on Rails application deployment as the main use case. And since I'd never worked in a RoR environment before, I had no real reason to look into it much. But in the last 3 months, I have worked at 2 different companies that use RoR + Capistrano for deployment and have learned enough to see it's true power. How I'd describe it to a fellow sysadmin is: "parallel execution of scripts and commands on multiple hosts...easily". Want to quickly execute a command on every host in your cluster? This is the way to do it.

Installing it is pretty easy...you need a modern version of Ruby, a modern version of RubyGems and then a gem install capistrano later, and you're good to go. You only need to install all of this on the controlling/deployment server....not on all your clusters/nodes. If you get errors with the version of ruby/gems that comes with your distro, install from source (recommended). I followed this tutorial to get it set up, and to get the basics. You sould read it as well. They skip a few necessary things (such as sudo and useful ENV variables) which I have below.

An example Capfile of how to restart apache on a whole cluster:

role :apache_cluster,"www1","www2","www3"
desc "restart apache on www hosts"  
task "restart_apache_www", :roles => :apache_cluster do  
sudo "/etc/init.d/apache2 restart"  
end

sudo is a built in method of modern versions of Capistrano. Instead of the 'run' method, you use 'sudo' and it understand and responds to the prompt (if prompted). Very slick. One thing to keep in mind is that is is running everything as YOU, unless otherwise specified. It will look like you logged into 50 servers all at once and ran sudo commands all at once. I bet that'd look cool on a Splunk log graph.

Now, from the command line, type 'cap -T' to get a list of your documented commands. As long as you describe your commands, you will always get a list of what you can run. 'cap -e command' will explain commands.

$ cap -T  
cap invoke # Invoke a single command on the remote servers.  
cap restart_apache_www # restart apache on www hosts  
cap shell # Begin an interactive Capistrano session.

Run the command we set up: 'cap restart_apache_www'. It will prompt for your password.

$ cap restart_apache_util  
* executing \`restart_apache_www'  
* executing "sudo -p 'sudo password: ' /etc/init.d/apache2 restart"  
servers: ["www01.domain.com", "www02.domain.com",
"www03.domain.com"]  
Password:  
[www01.domain.com] executing command  
[www03.domain.com] executing command  
[www02.domain.com] executing command  
** [out :: www01.domain.com] * Restarting web server apache2  
** [out :: www01.domain.com] ...done.  
** [out :: www03.domain.com] * Restarting web server apache2  
** [out :: www03.domain.com] ...done.  
** [out :: www02.domain.com] * Restarting web server apache2  
** [out :: www02.domain.com] ...done.command finished

And that was completed in parallel, in about 1 second. What if you have a one-off thing you want to run on all hosts? Try cap invoke, no Capfile required. If you have a Capfile with hosts defined, it will run against all of them by default, or it can take a role by passing ROLE as an env variable.

$ cap COMMAND=uptime HOSTS="www1,www2" invoke  
* executing \`invoke'  
* executing "uptime" servers: ["www1", "www2"]  
Password:  
[www1.prod] executing command  
[www2.prod] executing command  
** [out :: www1] 16:57:04 up 190 days, 4:30, 0 users, load average:
0.30, 0.33, 0.33  
** [out :: www2] 16:57:04 up 190 days, 4:42, 0 users, load average:
0.42, 0.32, 0.32  
command finished

and

cap ROLES=www COMMAND=uptime invoke  
* executing \`invoke'  
* executing "uptime" servers: ["www1", "www2", "www3"]  
Password:  
[www1] executing command  
[www2] executing command  
[www3] executing command  
** [out :: www1] 17:00:17 up 190 days, 4:33, 0 users, load average:
0.54, 0.37, 0.34  
** [out :: www2] 17:00:17 up 190 days, 4:46, 0 users, load average:
0.18, 0.27, 0.29  
** [out :: www3] 17:00:17 up 190 days, 5:02, 0 users, load average:
0.17, 0.22, 0.25  
command finished

But every time you 'invoke', you must re-type your password. Want to stay connected? Try the shell:

$ cap shell HOSTS="www1,www2"  
* executing \`shell'  
====================================================================  
Welcome to the interactive Capistrano shell! This is an experimental  
feature, and is liable to change in future releases. Type 'help' for  
a summary of how to use the shell.  
-------------------------------------------------------------------  
cap> uptime  
[establishing connection(s) to www1, www2]  
Password:  
** [out :: www1] 17:03:24 up 190 days, 4:36, 0 users, load average:
0.29, 0.32, 0.32  
** [out :: www2] 17:03:24 up 190 days, 4:49, 0 users, load average:
0.35, 0.30, 0.29  
cap> w  
** [out :: www1] 17:03:37 up 190 days, 4:36, 0 users, load average:
0.24, 0.31, 0.31  
** [out :: www1] USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT  
** [out :: www2] 17:03:37 up 190 days, 4:49, 0 users, load average:
0.30, 0.29, 0.28  
** [out :: www2] USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT  
cap> ls /tmp/blah  
*** [err :: www1] ls: cannot access /tmp/blah  
*** [err :: www2] ls: cannot access /tmp/blah  
*** [err :: www1] : No such file or directory  
*** [err :: www2] : No such file or directory  
error: failed: "sh -c 'ls /tmp/blah'" on www1,www2

Notice that errors show up with a 'err' line.

While useful and timesaving, this barely scratches the surface of the power of Capistrano. I suggest you read the "From the Beginning" doc on the Capistrano site. If you discover any cool recipes, share them in the comments on this blog and I'll publish them as a followup later (as I learn more recipes myself).

P.S. I think I'm going to add a feature to MachDB to export host lists in a format compatible with the Capfiles.

DIY Encrypted Password Vault

2009-03-30T00:00:00Z

This is something I've needed at various jobs/situations for years...a place to store the root/router/database/web passwords that only I can see. There are a lot of desktop/handheld apps for this but I always feel like I could lose the computer/handheld that it's on and I'd be boned. I'd rather have something I can stick on a server somewhere and access via a remote shell....or carry it around on a thumb drive. Here are the scripts:

encrypt.sh

#! /bin/sh 

openssl bf -a -salt -in $1.txt -out $1.bf && rm -v $1.txt

decrypt.sh

#! /bin/sh 

openssl bf -a -d -salt -in $1.bf

To use it, create a file named blah.txt that has your secret info in it. Run the encrypt script first:

$ ./encrypt.sh blah
enter bf-cbc encryption password:
Verifying - enter bf-cbc encryption password:
removed `blah.txt'

It will encrypt the file and remove it. Check the contents of the file:

$ cat blah.bf
U2FsdGVkX1/+ZGiXPSZX8MED9aXrm1NfIEjpv5vvFKo=

It's actually base 64 encoded so you can email it to yourself for safe keeping if you so choose.

To decrypt for reading:

$ ./decrypt.sh blah
enter bf-cbc decryption password:
secret host: secret password
secret host2: secret password2

Now take the encrypted output file and the 2 scripts, email it to yourself and store a copy on a thumb drive. :)

Why all phones need a silent ring

2009-03-23T00:00:00Z

Telemarketers, vendors and people I'd rather not communicate with frequently intrude on my early morning slumber (esp East Coast vendors), meetings, lunches, free time and life in general. And since they usually call from unrecognized numbers, I feel compelled to answer (could be something important, right?) A co-worker and I have been using a neat technique to remove these individuals ability to communicate with us...create a new contact called "Do Not Answer" with a custom silent ring tone. Each time they call from a new number, add them as an additional number to that contact. And with that silent ring, now they can't interrupt you in meetings, at home, early in the morning, etc.

I used iTunes to make a silent ringtone...you can download it here: iPhone Silent Ringone

automated nmap scans

2009-03-13T00:00:00Z

Whipped this up for work, figured I'd share with the world, since it's decently useful. Stick it in cron nightly, needs to run as root. It will run a diff on what it sees and email you if there are new ports/hosts that pop up on your networks. If you find errors or mods, use this: http://pastebin.com/f635a7517 to modify it and post in the comments.

#! /bin/sh

DIR="/opt/nmap/scans"  
NETWORKS="192.168.1.0-255"  
TODAY=`date +%Y%m%d`  
YESTERDAY=`date -d yesterday +%Y%m%d`

for network in $NETWORKS  
do  
nmap -n -sS $network -oG $DIR/$network.$TODAY.nmap  
done

for network in $NETWORKS  
do  
diff -I "^#" $DIR/$network.$TODAY.nmap
$DIR/$network.$YESTERDAY.nmap > $DIR/$network.$TODAY.diff  
done

for network in $NETWORKS  
do  
SIZE=`find $DIR/$network.$TODAY.diff -size +0b`
if [ "$SIZE" = "$DIR/$network.$TODAY.diff" ]  
then  
cat $DIR/$network.$TODAY.diff | mail -s "Change Detected for
$network" user@host.com  
fi  
done

automated disk partitioning with sfdisk

2009-01-04T00:00:00Z

I discovered sfdisk a few years ago (part of util-linux) and have been using it in automation scripts ever since. sfdisk is like fdisk, but is scriptable. So for example, to list the partitions on a disk:

[root@host]# sfdisk -l /dev/sdc

Disk /dev/sdc: 121601 cylinders, 255 heads, 63 sectors/track  
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from
0

Device Boot Start End #cyls #blocks Id System  
/dev/sdc1 0+ 121600 121601- 976760001 83 Linux  
/dev/sdc2 0 - 0 0 0 Empty  
/dev/sdc3 0 - 0 0 0 Empty  
/dev/sdc4 0 - 0 0 0 Empty

To list them in a dump format, suitable as input to sfdisk (for cloning, saving or for some wacky awesome script):

[root@host ]# sfdisk -d /dev/sdc# partition table of /dev/sdc  
unit: sectors

/dev/sdc1 : start= 63, size=1953520002, Id=83  
/dev/sdc2 : start= 0, size= 0, Id= 0  
/dev/sdc3 : start= 0, size= 0, Id= 0  
/dev/sdc4 : start= 0, size= 0, Id= 0

You can use that dump in a fashion like this to clone a disks's partition map:

sfdisk -d /dev/sdc | sfdisk /dev/sdd

Or for saving it and using it later:

sfdisk -d /dev/sdc > partition.sfdisk  
...  
sfdisk /dev/sdc < partition.sfdisk

End of 2008

2009-01-01T00:00:00Z

I have done a few things in the last few months that are worthy of mention. I haven't had much of a chance to blog about them or write them down, what with them all being back to back and then holidays, being sick, vacation, more holidays, more being sick. But here are some links to the media I've produced. Enjoy.

San Diego CA USA to Cabo San Lucas, Baja California Sur, MX (in 6 days, 2200+ miles, on my new BMW adventure motorcycle)

One month of beard growth in 5 seconds (an experiment in time lapse)

Deleting that same beard at high speed (an experiment with tracy's camera)

The mechanical wonderment behind a bowling alley machine

ssh tab completion on known_hosts

2008-11-05T00:00:00Z

It's silly I've waited this may years to go figure this out. Many of you may already know that modern installs of OpenSSH will tab complete hostnames based on what's in the /etc/hosts file. But there is a neat little addition to your .bashrc that will tack on the ability to tab complete hostnames based on what's in ~/.ssh/known_hosts. Add this to your .bashrc:

SSH_COMPLETE=( $(cat ~/.ssh/known_hosts | \\  
cut -f 1 -d " " | \\sed -e s/,.*//g | \\  
uniq ) )complete -o default -W "${SSH_COMPLETE[*]}" ssh

All your new shells will auto complete based on what hosts you've connected to once (and therefore have entries in the known_hosts file). Any host you've never visited, well it won't be there. If you want to filter it based on certain hosts (for example, hosts in a certain domain name), just add a | grep domain.com after the uniq. If you're like me, this will save a lot of keystrokes over the next few years.

Tip: If you cut and paste my text above and it gives errors, make sure your cut-n-paste didn't change the quotes. If you want to see what it's going to use (or troubleshoot/modify), you can run this on the command line:

cat ~/.ssh/known_hosts | \\  
cut -f 1 -d " " | \\  
sed -e s/,.*//g | \\  
uniq

New Midpipe

2008-09-28T00:00:00Z

Out for a hyperspin

Installed a new LeoVince midpipe on the Hypermotard earlier in the week (2am in the garage with a rubber hammer the night before an early meeting). Finally got a moment away from the keyboard to take it out for a spin tonight. Total awesomeness. It starts better, sounds better and runs better. I think it's a bit faster too. How awesome is that for the effort and price? I should have done this a long time ago.

Pics: Old and Busted. New Hotness.

I had also adjusted the bars a bit to be a tad higher, but I didn't like it. The turn signals are pointed at the ground 5 feet in front of me, which means my effective road use brightness went from 'are those lasers?' to 'dead lightning bug'. I may pick a position half way between this position and neutral. Will have to test it again later in the week when I've got some more time.

HD Video Test

2008-08-13T00:00:00Z

Finally got myself a video camera. Been looking at them critically for about 8 years now...ever since my Hi8 cam broke in 2000. I loved making movies back then, and even lately have been doing various time-lapse type videos...not really 'movies' since they were shot with a SLR. A few years ago I got interested in video again with the advent of consumer level HD cameras. Canon came out with the HF10 and HF100, soda-can sized cameras that record 1080p HD to SDHC flash cards...no moving parts, great for strapping to cars/motorcycles, etc. When the price finally fell to a range I could deal with, I pulled the trigger. It's so cool...and little! This is my first test. Video quality is great! I hope to be posting more mischief and fun events in the coming months.

Is Vimeo the best place to host HD video? Anyone? Bueller? Anyway, enjoy some test shots from the backyard...

HD Test - Backyard Oddities

changing your server over to GMT

2008-08-05T00:00:00Z

Funny how it's kind of hard to find documentation on this fairly simple task. The host I'm working with is CentOS 5, a variant of Redhat Enterprise 5. I use the following commands:

cat /usr/share/zoneinfo/GMT > /etc/localtime

That is actually what sets the time. It's a binary file and is what our system tools and libraries look at.

vi /etc/sysconfig/clock

Edit the ZONE to be GMT. Mine looks like this:

ZONE="GMT"
UTC=true
ARC=false

Verify it looks right with these commands.

date ; date -u ; /sbin/hwclock --show

Reboot, done!

Statistics, Charts and R

2008-06-02T00:00:00Z

R is an open source environment for statistical computing. It can do some pretty neat breakdowns of your data and has a lot of built in functions for doing so. One of it's great strengths is generating production quality graphics and charts. This is what I needed it for and what I'll be explaining here in a moment. I learned R by watching a video introduction to R created by Decision Science News. There were 2 actually. But not very long and it got me to a base level. I then installed R on my Mac, it was cake. Go to the R site, download the DMG, run the R executable and you're ready to go. That got me up and running so I could start playing around on my own and using other examples from the web. YMMV on other platforms.

Now for the example. Let's set the stage. Say you have some data in a table, for example, a race my girlfriend competed in, the 2006 San Diego 10K race. I copied, pasted that data into a file, scrubbed it down, did some math with perl to get me the # of seconds, and ended up with a CSV file. Download the file, save it locally, read that file in with R:

race<-read.csv("race.csv")

You are reading that CSV file in as a table into a variable called 'race'. Because that CSV has a header as the first line, it automatically assigns variables based on those column names. To reference those columns, use race$CITY, to check out the 'CITY' column. So to check out what you've just done, type "race</span>" on the console. Typing the variable name will spit it all back out. To see a breakdown of what that variable contains, type:

summary(race)

To see stats on the racers ages, type in:

summary(race$AGE)

Which spits out:

Min. 1st Qu. Median Mean 3rd Qu. Max.  
10.00 28.00 35.00 37.06 44.00 81.00

Minimum age of a runner was 10, oldest was 81. Average age was 37.06 years old. Doing this for race$SEX shows us there were 411 women and 474 men. Neat! Now for the visuals:

Below is a script I used to generate the graph above. You can see how I am plotting the dots, and drawing both lines:

race<-read.csv("race.csv")

Main Plot.

plot(race$SECONDS/60,race$AGE,  
col="#5fae27",  
main="",  
xlab="Minutes",  
ylab="Age",  
cex=0.5,  
type="p")

Set the Title

title(main="Age vs Time")

Draw the Red Line

lines(stats::lowess(race$SECONDS/60,race$AGE,f=0.1),  
col="red",  
lwd=2)

Draw the Blue Line

lines(stats::lowess(race$SECONDS/60,race$AGE,f=0.3),  
col="blue",  
lwd=3)

Not too hard, not too much code...pretty easy in fact! One of the great things about R is the built in help. Any of those functions, just type: ?function ..and you'll have immediate help. I encourage you to do that for the example above, to better understand it. It will describe far better than I can how each one of those functions works.

Let's generate another one, a histogram. That's easy:

hist(race$AGE,col="RED",xlab="Age",breaks=100,main="Histogram of
Racers Age"

To generate this:

So, what did I learn from the creation of this plot? My initial suspicion was that younger people would do better in the race...the data shows that is's almost average across the board. The average age is in the late 30's, but the histogram shows the biggest group was mid-late 20's. Hardly anyone in their early 20's even entered the race...too busy drinking? Also, there is a neat little cluster at the bottom left of the plot that shows a group of young kids in their teens that did well.

I have been making more of these, mostly around sysadmin type stuff. I'll post those as I get more time.

I got Joe Jobbed!

2008-04-16T00:00:00Z

In case you've never heard of this, getting 'Joe Jobbed' is when a spammer uses your e-mail address as the 'From:' in their spam and you get all the billion bounces. It rendered my Blackberry useless all afternoon, and I thought I'd finally be screwed on this one. Alas, SpamAssassin 3.2.0 and above (I'm running 3.2.4) comes with rules to block this. Unknown to me, most of the bounces were already going to my spam folder, but any that didn't have the spam body were getting to me. I followed the instructions on this page: http://wiki.apache.org/spamassassin/VBounceRuleset to make sure it was all set up and wouldn't classify bounces from my own server as bad. Then I set up the following procmail rule to put bounces in their own folder that I can review and run stats on:

:0:
* ^X-Spam-Status:.*ANY_BOUNCE_MESSAGE.*
bounces

Done!

More good reading on this: http://www.sitepoint.com/print/sabotage-coping-joe-job

UNIX paste, sed and nl commands

2008-02-27T00:00:00Z

3 highly useful commands you will find as part of your standard UNIX toolbox. I'll give an example situation for relevance:

I quite often find myself needing to merge 2 files together for some reason or another. My latest awesomeness consists of ripping/encoding favorite seasons of DVD's I own so my MediaCenter can have an easily accessed library (that I can also stream to my iPod Touch). When the encoding is done, I get files based on the name of the DVD Media and the track number. Like this:

Blah Season 1 Disc 1-1.mp4  
Blah Season 1 Disc 1-2.mp4  
Blah Season 1 Disc 1-3.mp4  
Blah Season 1 Disc 1-4.mp4  
Blah Season 1 Disc 2-1.mp4  
Blah Season 1 Disc 2-2.mp4  
Blah Season 1 Disc 2-3.mp4  
Blah Season 1 Disc 2-4.mp4

I can go to a place like Wikipedia or Amazon and find a list of the track names, that should look like this:

Pilot  
The Fat Man  
Little John  
Howard  
The Reconing  
Half Way  
Blah  
Blah Pt 2

What I want to end up with is files named something like this:

Blah - S01E01 - Pilot.mp4  
Blah - S01E02 - The Fat Man.mp4

It'd be so much easier to rename these on the command line if I could at least partly automate it. Re-typing is a PITA. So, here is how I do it to save a lot of time...

If I assume that they were ripped in order, I can get a listing of the order of the episode files based on the time stamps (ls) and add a " to the front and end of the line (sed commands):

# ls -tr *.mp4 \\  
| sed 's/^/"/g' \\  
| sed 's/$/"/g' > tracklist.txt

Next I go to Amazon, Wikipedia, whatever. Find a list of episodes that is represented with tables (which cut-n-pastes as individual lines with tabs as the delimiter) and paste it into a vi edit session:

# vi episodes.txt

In general, edit this file down to a point that the only thing that exists are the track names, one per line. Let's pretend the first column contained the name of the track, 2nd column the Writer, etc. We only care about the first column, so you can execute this command in vi:

:%s/\\t.*//g

You can do other various cleanup like removing the " character:

:%s/"//g

Clean up other stuff like invalid shell characters, extra spaces, etc. This is the least automated part, but a hell of a lot faster/easier than re-typing. Especially if you are a vi whiz. If you use some other text editor, I'm sure this can be accomplished in a similar fashion.

Now we have 1 file that is the list of mp4 files, in order, and another that is the episode names, in order. What we now need is to make a file with what we actually want the files to be named. I accomplish this with the following command-line awesomeness:

nl -n rz -w 2 -s " - " episodes.txt \\  
| sed "s/^/\\"Blah - S01E/g" \\  
| sed "s/$/.mp4\\"/g" \\  
> newnames.txt

To break that down, this is what is happening:

The nl command adds numbered lines...the -n means "right justified, padded zeros" and the -w means "padded with 2 characters" and the -s means "separate the columns with what's in the quotes".
The 2 sed commands add a " to the beginning and end of the lines.
The > sends the output to a file.

Output looks like this:

"Blah - S01E01 - Pilot.mp4"  
"Blah - S01E02 - The Fat Man.mp4"  
"Blah - S01E03 - Little John.mp4"  
"Blah - S01E04 - Howard.mp4"  
"Blah - S01E05 - The Reconing.mp4"  
"Blah - S01E06 - Half Way.mp4"  
"Blah - S01E07 - Blah.mp4"  
"Blah - S01E08 - Blah Pt 2.mp4"

Now we merge the 2 files and prepend the 'mv' command to get a script we can run:

paste tracklist.txt newname.txt \\  
| sed 's/^/mv /g' \\  
> script.sh

Which looks like this:

mv "Blah Season 1 Disc 1-1.mp4" "Blah - S01E01 - Pilot.mp4"  
mv "Blah Season 1 Disc 1-2.mp4" "Blah - S01E02 - The Fat Man.mp4"  
mv "Blah Season 1 Disc 1-3.mp4" "Blah - S01E03 - Little John.mp4"  
mv "Blah Season 1 Disc 1-4.mp4" "Blah - S01E04 - Howard.mp4"  
mv "Blah Season 1 Disc 2-1.mp4" "Blah - S01E05 - The Reconing.mp4"  
mv "Blah Season 1 Disc 2-2.mp4" "Blah - S01E06 - Half Way.mp4"  
mv "Blah Season 1 Disc 2-3.mp4" "Blah - S01E07 - Blah.mp4"  
mv "Blah Season 1 Disc 2-4.mp4" "Blah - S01E08 - Blah Pt 2.mp4"

Check the script for sanity, then run it!

bash -x script.sh

w00t!

If you want the shell script I use to automate this somewhat:

#! /bin/sh

ls -tr *.mp4 \\  
| sed 's/^/"/g' \\  
| sed 's/$/"/g' \\  
> tracklist.txt  
nl -n rz -w 2 -s " - " episodes.txt \\  
| sed "s/^/\\"$1 - $2E/g" \\  
| sed "s/$/.mp4\\"/g" \\  
> newnames.txt  
paste tracklist.txt newnames.txt \\  
| sed 's/^/mv /g' \\  
> script.sh

The arguments are the name of the series and the season, like this:

bash ./rename.sh Blah S01

P.S. If you're trying to guess the show by the track names, I made them up. :)

My Synergy Setup

2008-02-26T00:00:00Z

Synergy rules. I've been talking about it for a few weeks now, expounding on it's virtues over other options like x2vnc. A friend asked that I document my setup...here ya go Eddy: :)

My current install of synergy runs on on my Mac Pro, my linux box (centos5) and my MacBook Pro laptop. The Mac Pro is the controlling keyboard and reaches across both of the other computers. The monitor layout is the Mac Pro in front (2 monitors), the Linux box directly to the left and the laptop below the linux box.

After I downloaded synergy, I placed the 2 binaries (synergys,synergyc) in /usr/local/bin on my Mac. If the dir doesen't exist, create it. I also created /usr/local/etc for the config files.

Config on the Mac Pro:

n8pro:bin nathan$ cd /usr/local/bin
n8pro:bin nathan$ ls
jhead  jpegtran synergyc synergys xv

The config file on the Mac Pro:

n8pro:~ nathan$ cd /usr/local/etc/
n8pro:etc nathan$ cat synergy.conf
  section: screens
     n8pro.local:
     n8bookpro.local:
     homelinux:
  end
  section: links
     n8pro.local:
         left = homelinux
     homelinux:
         right = n8pro.local
         down = n8bookpro.local
n8bookpro.local:
   up = homelinux
  end

Commands I run on the Mac Pro (server):

# synergys -f -c /usr/local/etc/synergy.conf

Commands I run on the Linux Box (client):

# synergyc -f n8pro

Commands I run on the MacBook Pro (client):

# synergyc -f n8pro

Extra credit:

I also use this at work. A Linux box is the control. Synergyc will re-try connections every 30 sec or so, which means I can launch synergyc clients and let them fail when I'm not on the network. This means I can run it once and connect/disconnect from work/home networks and have seamless mouse sharing with very little work required. To set this up on the Linux box, i had a config similar to the one above for the Mac Pro. On the laptop I have one script that I run that fires off both synergyc clients at the same time. They stay running until a reboot. After reboot, I run it again and I'm set. This is the script:

cat /usr/local/bin/setup_synergy.sh
#! /bin/bash
killall synergyc
sleep 2
synergyc -f n8pro &
synergyc -f n8linuxbox &

Restoring lost screen sockets

2007-12-20T00:00:00Z

Do your screen sockets get nuked and you can't connect to your screen sessions? If something auto-cleans the /tmp dir, you may have seen this before. If you're like me, you end up with 10 or so shells with various programs running that you then have to follow the process tree to kill off. This is my only real (huge) frustration with screen. Well, here's ya go:

ps -x | grep SCREEN | awk '{print $1}' | xargs kill -CHLD

Enjoy!

Christmas tree decorating at high speed

2007-12-05T00:00:00Z

Your browser does not support the video tag.

If you watch closely, you can see some sillyness at the beginning. Hehe. Good stuff!

Peyton Lost, boooooo hoooooo

2007-11-12T00:00:00Z

I don't even like football, but I did tonight. >:-)

Go Chargers!!

Spiders on Drugs

2007-11-08T00:00:00Z

I guess everyone has seen this but me:

http://youtube.com/watch?v=sHzdsFiBbFc

In the 1960s, Dr. Peter Witt gave drugs to spiders and observed their effects on web building. This short film about the results of the experiment was created by First Church Of Christ, Filmmaker.