= SPRINKLE http://redartisan.com/2008/5/27/sprinkle-intro http://github.com/crafterm/sprinkle == DESCRIPTION: Sprinkle is a software provisioning tool you can use to build remote servers with, after the base operating system has been installed. For example, to install a Rails or Merb stack on a brand new slice directly after its been created. Properties of packages such as their name, type, dependencies, etc, and what packages apply to what machines is described via a domain specific language that Sprinkle executes (in fact one of the aims of Sprinkle is to define as concisely as possible a language for installing software). An example package description follows: package :ruby do description 'Ruby Virtual Machine' version '1.8.6' source "ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-#{version}-p111.tar.gz" requires :ruby_dependencies verify do has_file '/usr/bin/ruby' end end This defines a package called 'ruby', that uses the source based installer to build Ruby 1.8.6 from source, installing the package 'ruby_dependencies' beforehand. Additionally, the package verifies it was installed correctly by verifying the file '/usr/bin/ruby' exists after installation. If this verification fails, the sprinkle script will gracefully stop. Reasonable defaults are set by sprinkle, such as the install prefix, download area, etc, but can be customized globally or per package (see below for an example). Since packages come in many forms (eg. gems, pre-compiled debs, compressed source tar.gz, etc), Sprinkle supports many different installer types, giving you the most amount of flexibility of how you'd like software installed. New installer types can be added into the system easily. For example, you could install Rails via gems, nginx via source, and mysql via APT, while retaining the flexibility of changing installer types as software is updated upstream. Sprinkle also supports dependencies between packages, allowing you specify pre-requisites that need to be installed in order. Packages can be grouped into polices to define several packages that should be installed together. An example policy: policy :rails, :roles => :app do requires :rails, :version => '2.1.0' requires :appserver requires :database requires :webserver end This defines a policy called Rails, that applies to machines of role :app. The policy includes the packages rails (version 2.1.0), appserver, database and webserver. appserver, database and webserver can be virtual packages, where the user will be prompted for selection if multiple choices for the virtual package exist. Sprinkle is architected to be extendable in many ways, one of those areas is in its deployment of commands to remote hosts. Currently Sprinkle supports the use of Capistrano, Vlad, or a direct net/ssh connection to issue commands on remote hosts via ssh, but could also be extended to use any other command transport mechanism desired. Sprinkle can also be configured to simply issue installation commands to provision the local system. An full example Sprinkle deployment script for deploying Rails (via gems), MySQL (via APT), Apache (via source) and Git (via source with dependencies from APT): # Sprinkle Rails deployment script # # This is an example Sprinkle script, configured to install Rails from gems, Apache, Ruby and Git from source, # and mysql and Git dependencies from apt on an Ubuntu system. Installation is configured to run via # Capistrano (and an accompanying deploy.rb recipe script). Source based packages are downloaded and built into # /usr/local on the remote system. # # A sprinkle script is separated into 3 different sections. Packages, policies and deployment. # # Packages # # Defines the world of packages as we know it. Each package has a name and # set of metadata including its installer type (eg. apt, source, gem, etc). Packages can have # relationships to each other via dependencies # # Policies # # Names a group of packages (optionally with versions) that apply to a particular set of roles. # # Deployment # # Defines script wide settings such as a delivery mechanism for executing commands on the target # system (eg. capistrano), and installer defaults (eg. build locations, etc). # Packages package :ruby do description 'Ruby Virtual Machine' version '1.8.6' source "ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-#{version}-p111.tar.gz" requires :ruby_dependencies end package :ruby_dependencies do description 'Ruby Virtual Machine Build Dependencies' apt %w( bison zlib1g-dev libssl-dev libreadline5-dev libncurses5-dev file ) end package :mysql, :provides => :database do description 'MySQL Database' apt %w( mysql-server mysql-client ) end package :apache, :provides => :webserver do description 'Apache 2 HTTP Server' version '2.2.9' source "http://apache.wildit.net.au/httpd/httpd-#{version}.tar.bz2" do enable %w( mods-shared=all proxy proxy-balancer proxy-http rewrite cache headers ssl deflate so ) prefix "/opt/local/apache2-#{version}" post :install, 'install -m 755 support/apachectl /etc/init.d/apache2', 'update-rc.d -f apache2 defaults' end requires :apache_dependencies end package :apache_dependencies do description 'Apache 2 HTTP Server Build Dependencies' apt %w( openssl libtool mawk zlib1g-dev libssl-dev ) end package :rubygems do description 'Ruby Gems Package Management System' version '1.2.0' source "http://rubyforge.org/frs/download.php/38646/rubygems-#{version}.tgz" do custom_install 'ruby setup.rb' end requires :ruby end package :rails do description 'Ruby on Rails' gem 'rails' version '2.1.0' end package :mongrel do description 'Mongrel Application Server' gem 'mongrel' version '1.1.5' end package :mongrel_cluster, :provides => :appserver do description 'Cluster Management for Mongrel' gem 'mongrel_cluster' # :source => 'http://gems.github.com/' for alternate gem server version '1.0.5' requires :mongrel end package :git, :provides => :scm do description 'Git Distributed Version Control' version '1.5.6.3' source "http://kernel.org/pub/software/scm/git/git-#{version}.tar.gz" requires :git_dependencies end package :git_dependencies do description 'Git Build Dependencies' apt 'git', :dependencies_only => true end # Policies # Associates the rails policy to the application servers. Contains rails, and surrounding # packages. Note, appserver, database and webserver are all virtual packages defined above. If # there's only one implementation of a virtual package, it's selected automatically, otherwise # the user is requested to select which one to use. policy :rails, :roles => :app do requires :rails, :version => '2.1.0' requires :appserver requires :database requires :webserver requires :scm end # Deployment # Configures sprinkle to use capistrano for delivery of commands to the remote machines (via # the named 'deploy' recipe). Also configures 'source' installer defaults to put package gear # in /usr/local deployment do # mechanism for deployment delivery :capistrano do recipes 'deploy' end # source based package installer defaults source do prefix '/usr/local' # where all source packages will be configured to install archives '/usr/local/sources' # where all source packages will be downloaded to builds '/usr/local/build' # where all source packages will be built end end Please see the examples directory for more complete examples of Sprinkle deployment scripts. Sprinkle is a work in progress and I'm excited to hear if anyone finds it useful - please feel free to comment, ask any questions, or send in any ideas, patches, bugs. All most welcome. Marcus Crafter <crafterm@redartisan.com> == LICENSE: (The MIT License) Copyright (c) 2008 Marcus Crafter <crafterm@redartisan.com> Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.