Add bazaar (v1) SCM module (closes #3533)

git-svn-id: http://svn.rubyonrails.org/rails/tools/switchtower@3446 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

CHANGELOG

@@ -1,5 +1,7 @@
 *0.11.0* *SVN*
 
+* Add bazaar (v1) SCM module [Edd Dumbill] (#3533)
+
 * Fix stftime format string used in CVS module to be Windows-compatible (fixes #3383)
 
 * Add an better error when a task is run and no servers match the required conditions

lib/switchtower/scm/baz.rb

@@ -0,0 +1,118 @@
+require 'switchtower/scm/base'
+
+module SwitchTower
+  module SCM
+
+    # An SCM module for using Bazaar as your source control tool. This
+    # module is used by default, but you can explicitly specify it by
+    # placing the following line in your configuration:
+    #
+    #   set :scm, :baz
+    #
+    # Also, this module accepts a <tt>:baz</tt> configuration variable,
+    # which (if specified) will be used as the full path to the svn
+    # executable on the remote machine:
+    #
+    #   set :baz, "/opt/local/bin/baz"
+    #
+    # Set the version you wish to deploy as the repository variable, 
+    # for example:
+    #
+    #   set :repository, "you@example.com--dev/yourstuff--trunk--1.0"
+    #
+    # Ensure that you have already registered the archive on the target
+    # machines.
+    #
+    # As bazaar keeps a great deal of extra information on a checkout,
+    # you will probably want to use export instead:
+    #
+    #   set :checkout, "export"
+    #
+    # TODO: provide setup recipe to register archive
+    class Baz < Base
+      # Return an integer identifying the last known revision in the baz
+      # repository. (This integer is currently the revision number.)
+      def latest_revision
+        `#{baz} revisions #{configuration.repository}`.split.last =~ /\-(\d+)$/
+        $1
+      end
+
+      # Return the number of the revision currently deployed.
+      def current_revision(actor)
+        latest = actor.releases.last
+        grep = %(grep " #{latest}$" #{configuration.deploy_to}/revisions.log)
+        result = ""
+        actor.run(grep, :once => true) do |ch, str, out|
+          result << out if str == :out
+          raise "could not determine current revision" if str == :err
+        end
+
+        date, time, user, rev, dir = result.split
+        raise "current revision not found in revisions.log" unless dir == latest
+        rev.to_i
+      end
+
+      # Return a string containing the diff between the two revisions. +from+
+      # and +to+ may be in any format that bzr recognizes as a valid revision
+      # identifier. If +from+ is +nil+, it defaults to the last deployed
+      # revision. If +to+ is +nil+, it defaults to the last developed revision.
+      def diff(actor, from=nil, to=nil)
+        from ||= current_revision(actor)
+        to ||= latest_revision
+        from = baz_revision_name(from)
+        to = baz_revision_name(to)
+        `#{baz} delta --diffs -A #{baz_archive} #{baz_version}--#{from} #{baz_version}--#{to}`
+      end
+
+      # Check out (on all servers associated with the current task) the latest
+      # revision. Uses the given actor instance to execute the command.
+      def checkout(actor)
+        op = configuration[:checkout] || "get"
+        from = baz_revision_name(configuration.revision)
+        command = "#{baz} #{op} #{configuration.repository}--#{from} #{actor.release_path} &&"
+        run_checkout(actor, command, &baz_stream_handler(actor)) 
+      end
+
+      def update(actor)
+        command = "cd #{actor.current_path} && #{baz} update &&"
+        run_update(actor, command, &baz_stream_handler(actor)) 
+      end
+
+      private
+        def baz
+          configuration[:baz] || "baz"
+        end
+
+        def baz_revision_name(number)
+          if number.to_i == 0 then
+            "base-0"
+          else
+            "patch-#{number}"
+          end
+        end
+
+        def baz_archive
+          configuration[:repository][/(.*)\//, 1]
+        end
+
+        def baz_version
+          configuration[:repository][/\/(.*)$/, 1]
+        end
+
+        def baz_stream_handler(actor)
+          Proc.new do |ch, stream, out|
+            prefix = "#{stream} :: #{ch[:host]}"
+            actor.logger.info out, prefix
+            if out =~ /\bpassword.*:/i
+              actor.logger.info "baz is asking for a password", prefix
+              ch.send_data "#{actor.password}\n"
+            elsif out =~ %r{passphrase}
+              message = "baz needs your key's passphrase, sending empty string"
+              actor.logger.info message, prefix
+              ch.send_data "\n"
+            end
+          end
+        end
+    end
+  end
+end