Guard and Guard Interpreter for ruby_block

Chef Infra (archive)
1

Hi,

https://docs.chef.io/resource_ruby_block.html

Is it just me or am I correct in assuming that ruby_block does NOT support guard/guard interpreter?

I am trying to execute 2 resources (one a execute resource and another a ruby_block) and i want both these resources to NOT RUN if the PID is already up and running…

execute 'Start Weblogic Node Manager' do
  guard_interpreter :bash
  user node['weblogic']['user']
  group node['weblogic']['group']
  cwd node['weblogic']['user_project_bin']

  #This PID runs in the foreground by default, so need to use nohup & to run as a background process
  command "nohup ./startNodeManager.sh > chef_start_nodemanager.log 2>&1 &"

  # grep exits with 1 when no match is found. This resource is executed when not_if returns false i.e exit code is != 0 from bash script
  # So, this resource is run if grep doesn't find a match
  not_if 'ps -ef | grep weblogic.NodeManager | grep -v grep'
end


#Only run the below block if the SAME guard as above is false.....can that be done??   
ruby_block "Wait until Node Manager has started" do
  block do
     until File.readlines("#{node['weblogic']['domainhome']}/bin/chef_start_nodemanager.log").grep(/Plain socket listener started on port 5556, host localhost/).size > 0
         Chef::Log.info('sleeping 3 seconds until grep condition true')
         sleep 3
     end
  end
end

However, looking at the ruby_block documentation, there is no mention of a guard_interpreter/guard, so just checking if its supported.

Cheers

2

Hi there – the guard functionality should included in all built-in resources. Are you actually seeing a problem? It should just work.

3

FYI https://docs.chef.io/resource.html#common-functionality

4

Thank you. I think I got confused because I was expecting a Guards section within https://docs.chef.io/resource_ruby_block.html similar to how https://docs.chef.io/resource_ruby.html does.

5

A little off topic, but worth noting the | grep -v grep is easy to avoid.
Try with not_if 'ps -ef | grep "[w]eblogic.NodeManager"'
Using the brackets tell grep to match the same as you did but its own command line won't match as there will be brackets inside it.

6

Please don’t start services like this. Check out poise-service for an easy way to convert this into a real service management system.

1 Like