In chef, how do I access attributes within role files?

Question

I'm able to set attributes in role files as documented but I'm not able to access attributes already set by cookbooks that I'm using.

For example within /roles/appserver.rb:

name "appserver"

run_list(%w{
  recipe[tomcat::default]
})

default_attributes(
  :tomcat => {
    :java_options => "-XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=" + node[:tomcat][:log_dir]
  }
)

What I get is an exception stating chef can't find the 'node' method/variable.

Thanks

Answer 1

You cannot. The role Ruby DSL is converted from Ruby to JSON when you upload the role to the server with knife. The node object is not available, since it is not processed in the context of a Chef run.

If you want to combine node attributes, instead, you should do that in a recipe, for example:

"#{node[:tomcat][:java_options]}#{node[:tomcat][:log_dir]}"