timdoug.com - timdoug's interesting tidbits

timdoug's interesting tidbits

Little bits of technical documentation and such. Hopefully helpful.

2013-05-15

I can't install gcc on OpenLogic CentOS!

Yeah, someone really dropped the ball here. If you see this when you try to yum install gcc:

--> Finished Dependency Resolution
Error: Package: glibc-headers-2.12-1.80.el6_3.7.x86_64 (updates)
           Requires: kernel-headers
Error: Package: glibc-headers-2.12-1.80.el6_3.7.x86_64 (updates)
           Requires: kernel-headers >= 2.2.1
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

Then try doing this: sudo yum --disableexcludes=main install kernel-headers-*.el6.openlogic.x86_64

I don't know who's the idiot who put exclude=kernel* in /etc/yum.conf to break installing gcc, but...you're an idiot.

[/gcc] permanent link

2013-03-26

How to install and use Errbit through nginx & Passenger

Capistrano scares the shit out of me. I'd rather know what I'm deploying, rather than rely on some foreign script, thank you very much. To install Errbit and deploy with Passenger through nginx, try this:

git clone https://github.com/errbit/errbit.git
rake errbit:copy_configs
vi config/config.yml # and change hostnames / SMTP settings
vi config/mongoid.yml # and change production mongo settings
echo "Errbit::Application.config.secret_token = '$(bundle exec rake secret)'" > config/initializers/secret_token.rb
RAILS_ENV=production rake assets:precompile
RAILS_ENV=production rake db:mongoid:create_indexes
RAILS_ENV=production rake db:seed

Then add something like the following to your nginx config:

server {
    listen 8080;
    server_name errbit.example.com;
    root /wherever/errbit/public;
    passenger_enabled on;
    rails_env production;
}

[/general] permanent link

2013-01-23

Use tcpdump to download arbitrary Flash videos

I came across an interesting video on the web that I wanted to watch offline, but it played through a Flash application, there were no download links, grabbing the stream by looking through the HTML/DOM was nontrivial, and the youtube-dl mainstay didn't work. tcpdump to the rescue!

tcpdump -v -i <interface> -w output.cap
Load the video up and start playing. Sadly, this has to be done in real-time.
When done, tcpflow -r output.cap
The largest file should be your video; use an editor to strip the HTTP headers from the beginning.
If all goes well, you should have a video.flv. For extra credit, use ffmpeg -i video.flv to see if it's H.264/AAC. If so, use ffmpeg -i video.flv -acodec copy -vcodec copy video.mp4 for lossless container conversion to a standard MPEG-4 Part 14 file.

Thanks to this post for the tip.

[/general] permanent link

2013-01-21

How to send email through Gmail / Google Apps Email with the Amazon Linux AMI on EC2

First, install the Heirloom mailx client with yum install mailx. The NSS certificates included with the AMI are either out of date or incomplete, so you've got to grab the Equifax root cert and set it up yourself, like this:

wget https://www.geotrust.com/resources/root_certificates/certificates/Equifax_Secure_Certificate_Authority.cer
certutil -d ~/.mailcerts/ -A -t TC -n "Equifax Secure Certificate Authority" -i Equifax_Secure_Certificate_Authority.cer

Then set up your ~/.mailrc like this:

set smtp-use-starttls
set smtp=smtp://smtp.gmail.com:587
set smtp-auth=login
set smtp-auth-user="your_username@example.com"
set smtp-auth-password="your_password"
set from="your_username@example.com"
set nss-config-dir="~/.mailcerts"
set ssl-verify=warn

That last "ssl-verify=warn" line looks pretty dangerous, and it definitely could be. I needed it because otherwise mailx would bark with Comparing DNS name: "smtp.gmail.com" Continue (y/n)? and...giving up, instead of accepting any input. For whatever reason my Debian box works fine without this line. Also, one could use this line without setting up the root certificate appropriately, but that's playing a bit too fast and loose for me.

With this configuration you should be good to go with: echo "body here" | mailx -s "Subject here" recipient@example.com

[/aws] permanent link

2012-12-22

My 2007-era MacBookPro3,1 doesn't fully go to sleep / cannot wake from sleep with 10.8!

Yep, I had a reason to break out my old MBP and install the newest version of OS X on it. It works wonderfully for a five year old box (the SSD sure helps!), except for not being able to sleep properly. What worked for me was disabling "safe sleep" a la this hint.

sudo pmset -a hibernatemode 0
sudo nvram "use-nvramrc?"=false

Then restart. You can also remove /private/var/vm/sleepimage to save some space, which is nice.

[/osx] permanent link

2012-12-13

How to install a fully patched and up-to-date lighttpd on Debian unstable that passes Qualys SSL Labs' tests

...well, except for the cipher suites that require an OpenSSL >= 1.0.0, but that's an adventure for another day.

wget http://redmine.lighttpd.net/attachments/download/1395/ssl-compression.diff
wget http://ftp.us.debian.org/debian/pool/main/l/lighttpd/lighttpd_1.4.31-3.debian.tar.gz
wget http://ftp.us.debian.org/debian/pool/main/l/lighttpd/lighttpd_1.4.31.orig.tar.gz
tar xvzf lighttpd_1.4.31.orig.tar.gz
cd lighttpd-1.4.31/
tar xvzf ../lighttpd_1.4.31-3.debian.tar.gz
vi debian/control [and get rid of the dpkg-dev version dependency]
vi debian/rules [and get rid of the "export=config" line and the previous backslash]
patch -p1 <../ssl-compression.diff
debuild -us -uc
[then install all of the dependencies it barks about and try again...]
cd ..
sudo dpkg -i lighttpd_1.4.31-3_amd64.deb
sudo /etc/init.d/lighttpd restart

And make sure these options are in your lighttpd ssl.conf:

    ssl.cipher-list = "RC4-SHA:AES256-SHA:AES128-SHA:DES-CBC3-SHA"
    ssl.honor-cipher-order = "enable"
    ssl.use-sslv2 = "disable"
    ssl.use-sslv3 = "disable"
    ssl.use-compression = "disable"

timdoug's interesting tidbits

2013-05-15

2013-03-26

2013-01-23

2013-01-21

2012-12-22

2012-12-13

2012-02-08

2010-11-09

2010-08-27

2010-08-25

2010-07-26

2010-07-23

2010-04-15

2010-03-02

2009-12-28

2009-12-05

2009-12-01

2009-11-02

2009-10-18

2009-09-15

2009-08-25

2009-08-21

2009-08-09

2009-07-22

2009-07-21

2009-07-16

2009-06-23

2009-06-22

2009-06-18

2009-06-17

2009-06-06

2009-06-03

2009-06-02

2009-06-01