powdahound's lodge

Tricky Apache configuration bug

Tue, 10 Nov 2009 15:01:29 -0800

When using Apache’s DirectoryIndex directive make sure you don’t separate the values with commas. If you do, Apache will be looking for filenames ending in commas!

Bad: DirectoryIndex index.html, index.php, index.cgi

Good: DirectoryIndex index.html index.php index.cgi

This took me longer to figure out than it should have. :\

Colorize log output with ack

Sat, 10 Oct 2009 16:52:19 -0700

Adding color to log files makes them a lot easier to understand, especially when tailing them. That’s why tools like MultiTail were created, and some logging tools can output in color. Last night I realized color could be added to any log file using ack, an awesome grep replacement that I recently found.

For example, to make 404s red in a standard Apache access log:

tail -f /var/log/apache2/access.log | ack --passthru --color-match=red "^.* 404 .*$"

The --passthru option makes it so no lines are discarded. You can use multiple colors by piping the output through ack multiple times. The --flush option is needed to prevent pipe buffering issues and the --color option is needed to pass colors through. Here’s an example:

tail -f /var/log/apache2/access.log | ack --flush --passthru --color --color-match=green "^.* 200 .*" | ack --flush --passthru --color --color-match=yellow "^.* 302 .*" | ack --flush --passthru --color --color-match=red "^.* 404 .*"

You can use more complex colors like --color="white on_red" to make errors stand out even more.

I wonder what other cool things ack can do…

Note: You could also do this with perl, but it looks a lot less maintainable.

RegExhibit

Thu, 08 Oct 2009 11:25:02 -0700

RegExhibit:

Nice OSX app for testing regular expressions.

Sublime Text: The text editor you'll fall in love with

Sat, 26 Sep 2009 14:55:43 -0700

Sublime Text: The text editor you'll fall in love with:

This looks like a great editor, or at least the start of one.

The Truth About EPA City / Highway MPG Estimates

Sat, 19 Sep 2009 12:23:37 -0700

The Truth About EPA City / Highway MPG Estimates:

What a bizarre system…

ack -- better than grep, a power search tool for programmers

Fri, 18 Sep 2009 08:49:32 -0700

ack -- better than grep, a power search tool for programmers:

Another awesome tool I wish I’d found earlier.

mkscript - test script creator

Wed, 16 Sep 2009 22:50:00 -0700

I usually do something wrong when I create test scripts (typo in shebang, not executable, missing open PHP tag, etc) so I wrote a small tool called mkscript that can create them for me.

Basically, instead of doing:

echo '#!/usr/bin/python' > test.py
chmod a+x test.py

You just do:

mkscript test.py

It knows how to create scripts for bash, perl, php, python, and ruby based on the extension you provide. You can get it here.

Pair it with this vim function to execute the current file and you have a really quick way to create and run test scripts!

Read It Later: Save Your One Read Wonders

Sat, 05 Sep 2009 09:55:47 -0700

Read It Later: Save Your One Read Wonders:

Not sure how I didn’t find this until now, but it seems very cool.

Tahoe has Shut Down the Cloud Seeding Program

Thu, 27 Aug 2009 09:53:46 -0700

Tahoe has Shut Down the Cloud Seeding Program:

Hopefully we have a good natural snow year so I can make good use of that season pass!

MarIrssi is a great alternative to other Mac IRC clients.

Mon, 24 Aug 2009 19:46:53 -0700

MarIrssi is a great alternative to other Mac IRC clients.

Video: Douglas Crockford — The JSON Saga

Sat, 22 Aug 2009 16:14:52 -0700

Video: Douglas Crockford — The JSON Saga:

Learned a lot from this talk.

The launch years of today’s most popular websites | Royal...

Thu, 30 Jul 2009 08:09:35 -0700

The launch years of today’s most popular websites | Royal Pingdom

trickle

Sat, 11 Jul 2009 09:11:52 -0700

trickle:

Comes in handy when you have to upload a bunch of files over a slower connection.

Mac's DigitalColor Meter.app

Fri, 10 Jul 2009 08:16:35 -0700

Mac's DigitalColor Meter.app:

This is a great tool to learn if you’re on a Mac. It’s also an easy replacement for the ColorZilla Firefox addon.

"According to the Audi, the automaker’s three main tenets are Value, Precision, and..."

Sun, 05 Jul 2009 19:14:31 -0700

“According to the Audi, the automaker’s three main tenets are Value, Precision, and Fascination, and they all add up to Quality.”

- Three great things to strive for in software development as well.

VIDEO: What goes into German engineering - Audi’s TechDay Quality

Velocity 09: Adam Jacob and Ezra Zygmuntowicz, "Infrastructure in the Cloud Era"

Thu, 02 Jul 2009 08:53:48 -0700

Velocity 09: Adam Jacob and Ezra Zygmuntowicz, "Infrastructure in the Cloud Era":

Great talk on server bootstrapping and configuration in the cloud.

Focus first empty input element using jQuery

Mon, 29 Jun 2009 16:39:00 -0700

It’s often helpful to auto-focus form elements for users of your site so they don’t have to manually select them with the mouse. I’d been using the following code on a few sites:

It will focus the first input element on the page that is visible, enabled, doesn’t contain any text, and doesn’t have the class ‘nofocus’ (so you can avoid search fields or other secondary inputs). One of the cool things about jQuery is that you can write some really short code to do very powerful things. Here’s my jQuery implementation of the above code:

The only functionality that is lost is focusing of text and password fields only. jQuery’s selectors make it easy to select all input elements, just text, or just password, but not “text OR password” as far as I can tell. If you can make it any shorter please let me know!

Using Gmail as Sendmail's relay

Fri, 26 Jun 2009 14:02:34 -0700

Comcast just started blocking port 25 at my house which caused sendmail to be unable to connect to external mail servers to deliver mail. Some people have been able to convince Comcast to open up the port for them but we weren’t so lucky. Instead, I changed sendmail to use Gmail’s SMTP server as its relay server.

Before making these changes I’d see lots of errors in /var/log/mail.log ending in stat=Deferred: Connection timed out with aspmx2.googlemail.com. or something similar. Trying to telnet aspmx2.googlemail.com 25 would result in a timeout.

I found all the information on how to do this in these two articles; Yan Li’s Words: Gmail, Fetchmail and Sendmail on UNIX/Linux and Linux, Sendmail and Gmail.com.

All of this was done on a server running Ubuntu 8.04.2 and sendmail 8.14.2.

Step 1

Edit your /etc/mail/sendmail.mc and add the following above the MAILER_DEFINITIONS block at the bottom. I tried putting these lines at the very bottom of the file the first time and it didn’t work. I suggest copy/pasting because the quotes are very strange.

define(`SMART_HOST',`smtp.gmail.com')dnl
define(`RELAY_MAILER_ARGS', `TCP $h 587')dnl
define(`ESMTP_MAILER_ARGS', `TCP $h 587')dnl
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
FEATURE(`authinfo',`hash /etc/mail/auth/client-info')dnl

Step 2

Create the /etc/mail/auth/client-info file by running:

% mkdir -p /etc/mail/auth
% chmod 700 /etc/mail/auth
% touch /etc/mail/auth/client-info
% chmod 600 client-info

Step 3

Edit /etc/mail/auth/client-info and fill it with the lines below. Replace user_id with your Gmail user id (user_id@gmail.com) and password with your password. Make sure there is a blank line at the end of the file.

AuthInfo:smtp.gmail.com "U:smmsp" "I:user_id" "P:password" "M:PLAIN"
AuthInfo:smtp.gmail.com:587 "U:smmsp" "I:user_id" "P:**password" "M:PLAIN"

Step 4

Compile the client-info file.

% cd /etc/mail/auth
% makemap -r hash client-info.db < client-info

Step 5

Compile update sendmail.cf with our sendmail.mc changes.

% cd /etc/mail
% make

Step 6

Reload the sendmail configuration.

/etc/init.d/sendmail reload

Now if you check your /var/log/mail.log you should see any queued messages being sent properly. You should see relay=smtp.gmail.com and stat=Sent. If not, make sure you didn’t miss a step above.

Keeping a website's footer at the bottom of the page

Wed, 24 Jun 2009 16:07:50 -0700

I was trying to do this and found these two links very helpful:

RRD Tools

Tue, 23 Jun 2009 11:17:09 -0700

RRD Tools:

I made this small tool to help calculate values needed when creating RRAs for RRD files and put it on Google App Engine. Will probably add more utilities later as I find myself wanting them.