Tim Dysinger

I deploy Rails and Ruby projects using capistrano and I manage my source control with git. Git is most typically accessed with a ssh key and not username-password. There is a way to proxy your key through your deploy server making it possible for capistrano to retrieve the code from a 3rd party (gitub or gitorious or ssh-enabled git-server). It’s called ssh agent. Not many people use it but it’s super handy and comes built in to most flavs of Linux and OS X Leopard.

Assuming you have already put your desktop public key in the git server’s authorized keys or on github/gitorious you have put your ssh public key in your profile. What you do is this:

echo >$HOME/.ssh/config <<\EOF
Host *.mydeployservers.com
  ForwardAgent yes
Host *.myotherdeployservers.com
  ForwardAgent yes
Host *
  ForwardAgent no
EOF
chmod -R go-rwsx $HOME/.ssh

Now SSH-Agent is setup to forward your keys through the deploy server and and you are ready to do some deploying. You may need to login to the deploy server once and try to login to the git server (github or the like) one time to accept the servers ssh key and stash in the deploy server/user’s local “known_hosts” file.

ssh myuser@mydelpoyserver.com
# (and from there)
ssh git@github.com
# the login will fail but the important part is accepting the server's ssh key
exit

Now back on your desktop you can now deploy from github or the like without “deploy keys”.

ssh-add ; #only need to do this once per login to your desktop
cap deploy

Posted on April 30th, 2008 by dysinger
Filed under: @work | 2 Comments »

I have prepared a new Ubuntu Hardy Amazon AMI image(s). They are in my ubuntu-ami bucket. I’ll start with a “small” ec2 instance image. The public AMI is “ami-4f7a9f26″. It is meant to be started with AKI “aki-9b00e5f2″ (which comes with fuse). The image is a bare-bones ubuntu hardy standard install. You can update it with the software you need. I will have 64-bit versions available early next week. The emphasis on my images is clean and tidy. I don’t install a bunch of crud that you may or may not need. It’s just the basics with a userdata-boot-hook (give the image a bash script at boot-time as userdata).

Here is how I created the image:

# Bootstrap
mkdir /mnt/ubuntu
debootstrap --arch i386 hardy /mnt/ubuntu

# Start
cat /proc/mounts >/mnt/ubuntu/etc/mtab
mount -o rbind /proc /mnt/ubuntu/proc
mount -o rbind /dev /mnt/ubuntu/dev
mount -o rbind /sys /mnt/ubuntu/sys
cat /etc/resolv.conf >/mnt/ubuntu/etc/resolv.conf
chroot /mnt/ubuntu /bin/bash

# Hostname
echo '127.0.0.1 localhost' >/etc/hosts

# Tidy
rm -rf tmp && ln -sf var/tmp tmp
rm -rf opt && ln -sf usr/local opt

# Locale
localedef -i en_US -c -f UTF-8 en_US.UTF-8
echo 'LANG="en_US.UTF-8"' >/etc/default/locale

# Update
cat >/etc/apt/sources.list < <\EOF
deb http://us.archive.ubuntu.com/ubuntu hardy main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu hardy main restricted universe multiverse
deb http://us.archive.ubuntu.com/ubuntu hardy-updates main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu hardy-updates main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu hardy-security main restricted universe multiverse
deb-src http://security.ubuntu.com/ubuntu hardy-security main restricted universe multiverse
EOF
gpg --keyserver wwwkeys.pgp.net --recv-keys A70DAF536070D3A1
gpg --armor --export A70DAF536070D3A1 | apt-key add -
cat >/etc/apt/sources.list.d/debian.list < <\EOF
deb http://http.us.debian.org/debian/ unstable main contrib non-free
deb-src http://http.us.debian.org/debian/ unstable main contrib non-free
deb http://http.us.debian.org/debian/ experimental main contrib non-free
deb-src http://http.us.debian.org/debian/ experimental main contrib non-free
EOF
cat >/etc/apt/apt.conf < <\EOF
APT::Default-Release "hardy";
EOF
apt-get update
apt-get install -y libc6-xen
rm -rf /lib/tls
apt-get upgrade -y
apt-get install -y ubuntu-standard

# Modules
wget -O - \
  http://s3.amazonaws.com/ec2-downloads/ec2-modules-2.6.18-xenU-ec2-v1.0-i686.tgz | \
  tar --no-same-owner -xzC /
depmod -a
echo 'loop' >>/etc/modules

# Color
perl -p -i -e ’s/xterm-color/xterm\*color/g’ /etc/skel/.bashrc ~/.bashrc
apt-get install -y ncurses-term 

# TTY
rm -f /etc/event.d/tty[2-6]

# Network
shadowconfig on
usermod -p \
  `dd if=/dev/urandom count=50 2> /dev/null | md5sum | cut -d ” ” -f1-1` \
  root
mkdir /etc/skel/.ssh
chmod 600 /etc/skel/.ssh
cp -r /etc/skel/.ssh /root
apt-get install -y ntp openssh-server
cat >/etc/ssh/sshd_config < <\EOF
Protocol 2
StrictModes yes
MaxStartups 10:30:60
Ciphers aes256-cbc,aes256-ctr
PasswordAuthentication no
ChallengeResponseAuthentication no
Subsystem sftp /usr/lib/openssh/sftp-server
UseDNS no
EOF
cat >/etc/network/interfaces < <\EOF
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
EOF

# Boot
cat >/etc/rc.local < <\EOF
#!/bin/sh -e
# Root SSH Public Key
mkdir -p /root/.ssh >/dev/null 2>&1
wget -q -O - http://169.254.169.254/2008-02-01/meta-data/public-keys/0/openssh-key \
  >/root/.ssh/authorized_keys
chmod -R go-rwsx /root
# Userdata Shell Script
wget -q -O - http://169.254.169.254/2008-02-01/user-data | sh
exit 0
EOF

# Fstab
cat >/etc/fstab < <\EOF
/dev/sda1 /    ext3 user_xattr 0 1
/dev/sda2 /mnt ext3 user_xattr 0 2
/dev/sda3 swap swap sw         0 0
EOF

# EC2 tools
apt-get install -y symlinks unzip ruby libopenssl-ruby1.8 curl ca-certificates
cd /tmp
wget http://s3.amazonaws.com/ec2-downloads/ec2-ami-tools.zip
cd /usr/local
unzip /tmp/ec2-ami-tools.zip
ln -sf `find . -type d -name ec2-ami-tools*` ec2-ami-tools
chmod -R go-rwsx ec2*
rm -rf /tmp/ec2*

# Bundle
rm /bin/sh && ln -s /bin/bash /bin/sh ; # make bash the default for ec2
modprobe loop ; # bundle image needs this
cat >/usr/local/sbin/image < <\EOF
#!/bin/bash
export EC2_AMITOOL_HOME=/usr/local/ec2-ami-tools
PATH=$EC2_AMITOOL_HOME/bin:$PATH
BUNDLE=`date '+%y%m%d%H%M%S'`
ec2-bundle-vol -r i386 -u $AMAZON_USER_ID --fstab /etc/fstab \
  -k $EC2_PRIVATE_KEY -c $EC2_CERT -b -d /mnt -s 10240 -e /root/.ssh -p $BUNDLE
ec2-upload-bundle -b $HOSTNAME -m /mnt/$BUNDLE.manifest.xml \
  -a $AMAZON_ACCESS_KEY_ID -s $AMAZON_SECRET_ACCESS_KEY
rm -rf /mnt/$BUNDLE* /mnt/img-mnt
EOF
chmod 700 /usr/local/sbin/image

export HOSTNAME=ubuntu-ami
apt-get clean
apt-get autoclean
apt-get autoremove
symlinks -cdrsv /
rm -rf /var/tmp/* ~/.bash_history
image

# Register & make the ami public (on another machine)
ec2-register $HOSTNAME/XXXXXXXXXXXXX.manifest.xml
ec2-modify-image-attribute ami-XXXXXXX --launch-permission -a all

# Run
ec2-run-instances \
  -K ~/.amazon/pk.pem -C ~/.amazon/cert.pem \
  -k mykey --kernel aki-9b00e5f2 \
  ami-XXXXXXXXXXX

Posted on April 27th, 2008 by dysinger
Filed under: @work | No Comments »

%w(rubygems rack).each { |dep| require dep }
Rack::Handler::Mongrel.run(
  lambda { |e| [
      301,
      { ‘Location’ => ‘http://rubyurl.com/g6L’ },
      ’:P’
    ]
  },
  :Port => 3000
)

Posted on April 25th, 2008 by dysinger
Filed under: @work | No Comments »

I downloaded and gave VirtualBox a twirl this week.  For those of you who haven’t heard of it, VirtualBox is a drop-in free and open source replacement for VMWare Fusion or Parallels.  Did I mention it’s open source and free?  Here’s the subversion repository.

Update 4/24/2008: I purchased VMWare Fusion last year and my rebate check never came.  Peter contacted me and made sure my rebate was on the way.  There’s nothing wrong with VMWare. It’s a fine tool. I just always have a leaning towards open source where ever possible.

Posted on April 18th, 2008 by dysinger
Filed under: @work | 1 Comment »

I wanted to try out stacked git for maintaining patches. Here is how I did it on my mac.

git clone http://homepage.ntlworld.com/cmarinas/stgit.git
cd stgit
git checkout -b stable origin/stable
sudo python setup.py install --prefix=/usr/local

Here is some resources to get started using stacked git.

• StGit Home Page
• StGit Tutorial
• Crash Course

Posted on April 5th, 2008 by dysinger
Filed under: @work | No Comments »