Fixing #2914 - pre/post hooks now work for transactions

This was built to be used with etckeeper to version control
files in /etc, but can be used for essentially anything.

This patch was built to be added to 0.25.4, so it's a least-modify
approach.  A better approach would be to refactor application/puppet.rb
just a bit so it uses Configurer more.

This is a simple patch - it just defines 'prerun_command' and 'postrun_command'
settings, and runs the appropriate command around each transaction
if they're set.

Signed-off-by: Luke Kanies <luke@reductivelabs.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/lib/puppet/configurer.rb b/lib/puppet/configurer.rb
index 3e72fa574..ec61272ef 100644
--- a/lib/puppet/configurer.rb
+++ b/lib/puppet/configurer.rb
@@ -5,6 +5,8 @@ require 'puppet/network/http_pool'
 require 'puppet/util'
 
 class Puppet::Configurer
+    class CommandHookError < RuntimeError; end
+
     require 'puppet/configurer/fact_handler'
     require 'puppet/configurer/plugin_handler'
 
@@ -39,6 +41,14 @@ class Puppet::Configurer
         @catalog = nil
     end
 
+    def execute_postrun_command
+        execute_from_setting(:postrun_command)
+    end
+
+    def execute_prerun_command
+        execute_from_setting(:prerun_command)
+    end
+
     # Initialize and load storage
     def dostorage
         begin
@@ -75,6 +85,8 @@ class Puppet::Configurer
         download_plugins()
 
         download_fact_plugins()
+
+        execute_prerun_command
     end
 
     # Get the remote catalog, yo.  Returns nil if no catalog can be found.
@@ -160,6 +172,8 @@ class Puppet::Configurer
         # Now close all of our existing http connections, since there's no
         # reason to leave them lying open.
         Puppet::Network::HttpPool.clear_http_instances
+    ensure
+        execute_postrun_command
     end
 
     private
@@ -180,4 +194,14 @@ class Puppet::Configurer
 
         return timeout
     end
+
+    def execute_from_setting(setting)
+        return if (command = Puppet[setting]) == ""
+
+        begin
+            Puppet::Util.execute([command])
+        rescue => detail
+            raise CommandHookError, "Could not run command from #{setting}: #{detail}"
+        end
+    end
 end