Capistrano for System Administrators (not rails developers) Bryan McLellan Senior Systems Administrator Widemile

Landing Page Optimization (LPO) by way of Secret Sauce with new SaaS Partner Platform Front end F5 VIP Cluster

Landing Page Optimization (LPO) by way of Secret Sauce with new SaaS Partner Platform Debian Host Blades w/VMware Server Debian Guests w/Apace fronted JBoss Clusters Front end Debian Guests w/Apace fronted JBoss Clusters Debian Guests w/Apace fronted JBoss Clusters Debian Guests w/Apace fronted JBoss Clusters F5 VIP Cluster

Landing Page Optimization (LPO) by way of Secret Sauce with new SaaS Partner Platform Debian Host Blades w/VMware Server Debian Guests w/Apace fronted JBoss Clusters Front end Database Backend Debian Guests w/Apace fronted JBoss Clusters Debian Guests w/Apace fronted JBoss Clusters Debian Guests w/Apace fronted JBoss Clusters F5 VIP Cluster MSSQL Cluster

Capistrano is Puppet for the Rails community

Not Invented Here ?

Puppet Ruby / Ruby-ish Written by a Systems Administrator Luke Kanies – Reductive Labs Designed to manage server configuration Capistrano Ruby / Ruby-ish Written by a Rails Developer Jamis Buck – 37signals Designed to deploy web applications Who is your daddy, and what does he do?

Why use Capistrano when we have Puppet? Heard during a Capistrano talk at OSCON Restart a particular service on multiple servers once Check the state of a service or resource (memory, cpu) that isn’t monitored Run a command on multiple servers AND monitor it’s output Systems deployment tasks: install puppet, build VMs, etc.

Installing Capistrano 1.Install ruby 2.Install ruby gems 3.gem install capistrano Wait, what’s a GEM? Yet another package manager

Not Invented Here ?

Not all package management systems are created equal. Debian doesn’t need another package management system. We have our own, it works quite well, thank you. PLEASE do not install unpackaged software on production systems that someone else might have to inherit after your very timely demise. Also note that ‘gem update –system’ tends to break Debian/Ubuntu ruby installations, and is disabled in libgems-ruby

Building a Capistrano deb 1.apt-get install build-essential fakeroot ruby-pkg-tools 2.svn checkout svn://svn.debian.org/pkg-ruby-extras/packages-wip/capistrano/trunk/ 3.wget 4.tar -xvzf capistrano tgz 5.mv trunk/* capistrano-2.2.0/ 6.cd capistrano-2.2.0/ 7.dch –v dpkg-buildpackage –rfakeroot 1.cd.. 2.sudo dpkg -i capistrano_ _all.deb 3.apt-get install -f

fastthread who? $ cap –V You are running Ruby 1.8.6, which has a bug in its threading implementation. You are liable to encounter deadlocks running Capistrano, unless you install the fastthread library, which is available as a gem: gem install fastthread Wait, we’re installing a gem to fix a bug in ruby? This is fixed in ruby1.8 >= p110 ( ubuntu1.1), no worries.

Using Capistrano invoke Assumptions: You can access your servers via SSH – There is some kind of proxy gateway functionality too You have the same password on all servers or PKI configured $ cap HOSTS="ots01, ots02, ots03" COMMAND="whoami" invoke * executing `invoke‘ * executing "whoami“ servers: ["ots01", "ots02", "ots03"] [ots01] executing command [ots02] executing command [ots03] executing command ** [out :: ots01] bryanm ** [out :: ots02] bryanm ** [out :: ots03] bryanm command finished

Why use Capistrano when we have Puppet? Heard during a Capistrano talk at OSCON Restart a particular service on multiple servers once $ cap HOSTS="ots01, ots02, ots03" COMMAND=“/etc/init.d/apache2 restart" invoke Check the state of a service or resource (memory, cpu) that isn’t monitored $ cap HOSTS="ots01, ots02, ots03" COMMAND="grep MemTotal /proc/meminfo" invoke Run a command on multiple servers AND monitor it’s output $ cap HOSTS="ots01, ots02, ots03" COMMAND=“tail –f /var/log/apache2/error.log" invoke Systems deployment tasks: install puppet, build VMs, etc. $ cap -S recipe=debian_client -S client=newbox01 build

Using Capistrano shell $ cap HOSTS="ots01, ots02, ots03" shell * executing `invoke‘ cap> ls [establishing connection(s) to ots01, ots02, ots03] cap> ps ** [out :: ots01] PID TTY TIME CMD ** [out :: ots01] ? 00:00:00 sshd ** [out :: ots01] ? 00:00:00 ps ** [out :: ots03] PID TTY TIME CMD ** [out :: ots03] 3222 ? 00:00:00 sshd ** [out :: ots03] 3231 ? 00:00:00 ps ** [out :: ots02] PID TTY TIME CMD ** [out :: ots02] ? 00:00:00 sshd ** [out :: ots02] ? 00:00:00 ps

Using Capistrano shell Sure, but I can do that with ClusterSSH, right? How about on fifty hosts? Programmatically? $ cap -S recipe=iclassify -S query="tag:ots-server" COMMAND="/etc/init.d/apache2 restart" SUDO=1 invoke $ cap -S recipe=iclassify -S query="tag:workstation" puppet

Andrew Shafer – Reductive Labs “Parallel to the ‘Developer’ tribe in most organizations, often with a semi-antagonistic mutual dependence, there was always another tribe: ‘Sysadmin’. When Developers and Sysadmins got together, it sometimes felt like the dwarfs and high elves forced to work together by necessity. (I’ll let you workout which is which.)”