Add hooks for plugins in knife bootstrap

Most cloud plugins override #run today because they have additional
steps, such as being able to create an instance in the cloud before we
bootstrap it. This means it's easy for them to get out of sync.

This is a proposal for some hooks that enable better code reuse.

Signed-off-by: Bryan McLellan <btm@loftninjas.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/lib/chef/knife/bootstrap.rb b/lib/chef/knife/bootstrap.rb
index 475cb43199..0826a0f38c 100644
--- a/lib/chef/knife/bootstrap.rb
+++ b/lib/chef/knife/bootstrap.rb
@@ -539,15 +539,18 @@ class Chef
         check_license
         verify_deprecated_flags!
 
+        plugin_setup!
         validate_name_args!
         validate_protocol!
         validate_first_boot_attributes!
         validate_winrm_transport_opts!
         validate_policy_options!
+        plugin_validate_options!
 
         winrm_warn_no_ssl_verification
         warn_on_short_session_timeout
 
+        plugin_create_instance!
         $stdout.sync = true
         connect!
         register_client
@@ -555,6 +558,7 @@ class Chef
         content = render_template
         bootstrap_path = upload_bootstrap(content)
         perform_bootstrap(bootstrap_path)
+        plugin_finalize
       ensure
         connection.del_file!(bootstrap_path) if connection && bootstrap_path
       end
@@ -772,6 +776,40 @@ class Chef
         true
       end
 
+      # Validate any additional options
+      #
+      # Plugins that subclass bootstrap, e.g. knife-ec2, can use this method to validate any additonal options before any other actions are executed
+      #
+      # @return [TrueClass] If options are valid or exits
+      def plugin_validate_options!
+        true
+      end
+
+      # Create the server that we will bootstrap, if necessary
+      #
+      # Plugins that subclass bootstrap, e.g. knife-ec2, can use this method to call out to an API to build an instance of the server we wish to bootstrap
+      #
+      # @return [TrueClass] If instance successfully created, or exits
+      def plugin_create_instance!
+        true
+      end
+
+      # Perform any setup necessary by the plugin
+      #
+      # Plugins that subclass bootstrap, e.g. knife-ec2, can use this method to create connection objects
+      #
+      # @return [TrueClass] If instance successfully created, or exits
+      def plugin_setup!
+      end
+
+      # Perform any teardown or cleanup necessary by the plugin
+      #
+      # Plugins that subclass bootstrap, e.g. knife-ec2, can use this method to display a message or perform any cleanup
+      #
+      # @return [void]
+      def plugin_finalize
+      end
+
       # If session_timeout is too short, it is likely
       # a holdover from "--winrm-session-timeout" which used
       # minutes as its unit, instead of seconds.