attribute value availability + the implicit dependency graph and chef-deploy patch

[Ian Kallen <spidaman.list@gmail.com>]

Last night I was seeing an issue where provisioning "apache + passenger 
worked" but "apache + passenger + rails app" (deploying the rails app 
w/chef-deploy) was failing. In the first scenario, the passenger 
cookbook's attributes was able to access the apache cookbook's 
attributes. In the second scenario, the apache attributes were *not* 
accessible to passenger's. But in all cases apache attributes are 
accessible in the passenger recipe script. In the second scenario I 
launched with { "recipes" : [ "railsapp" ] }, since the rails app recipe 
has 'include_recipe "passenger"' and the passenger recipe has 
'include_recipe "apache"' I expected the dependencies declared via 
include_recipe to be traversed to make the attribute values available. 
But apparently that doesn't work, cookbook processing order is random 
(?!). This was really frustrating to debug (the symptom was template 
names/paths mysteriously null valued and fairly useless error messages 
in the ensuing stacktrace);  are there docs I've overlooked on how 
cookbooks relate to each other as far as execution order and data model 
life cycles? <fujin> mentioned plans for something like a 
"require_attribute" operator in the conception phase, which sounds 
great, though it seems like requiring a recipe should be sufficient to 
carry attribute values forward; there's a dependency graph already 
implied by the "require_recipe" operator. If there are docs I've 
overlooked, forgive the length and thanks for reading this far :)

Finally, the chef-deploy resource seemed to be puking on some path 
disagreements as well as null valued config elements, diff attached.
thanks!
-Ian

--
Ian Kallen
blog: http://www.arachna.com/roller/spidaman
tweetz: http://twitter.com/spidaman
vox: 415.505.5208

--- a/lib/chef-deploy/cached_deploy.rb
+++ b/lib/chef-deploy/cached_deploy.rb
@@ -24,7 +24,9 @@ class CachedDeploy
   end
   
   def restart
-    unless @configuration[:restart_command].empty?
+    #unless @configuration[:restart_command].empty?
+    # undefined method `empty?' for nil:NilClass
+    if @configuration.has_key? :restart_command && 
@configuration[:restart_command]
       Chef::Log.info "restarting app: #{latest_release}"
       Chef::Log.info run(@configuration[:restart_command])
     end
@@ -63,7 +65,7 @@ class CachedDeploy
   
   def migrate
     if @configuration[:migrate]
-      run "ln -nfs #{shared_path}/config/database.yml 
#{latest_release}/config/
+      run "ln -nfs #{shared_path}/cached-copy/config/database.yml 
#{latest_rele
       Chef::Log.info "Migrating: cd #{latest_release} && 
RAILS_ENV=#{@configura
       Chef::Log.info run("cd #{latest_release} && 
RAILS_ENV=#{@configuration[:e
     end
@@ -175,4 +177,4 @@ class CachedDeploy
     def copy_exclude
       @copy_exclude ||= Array(configuration.fetch(:copy_exclude, []))
     end
-end
\ No newline at end of file
+end