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I need to run some commands depending on a result of previous execution, which again depends on some package being installed.

On the first run, I'd expect something like:

install package "XXX"
get output from XXX
for each line in output:
    if missing, use XXX to add
    if unknown, use XXX to delete

The problem is that when I do the logic in top level of the recipe, then the get output part will happen before package XXX is installed. I'd really like to just order those parts by using a ruby block (enforcing execution when the resources are processed), but then it seems I cannot nest execute resources inside of a ruby block resource.

How can I implement this correctly?

The recipe goes something like this:

flavors_bag = data_bag_item('nova', 'flavors')

cmd ="nova-manage flavor list")
flavors = cmd.run_command.stdout

flavors_bag['spec'].each do |flavor|
  execute "nova-manage flavor create #{flavor['name']} #{flavor['ram']*1024} #{flavor['cpu']} #{flavor['disk']} #{flavor['id']}" do
    action :run
    not_if {flavors.include? flavor['name']}

['some', 'old', 'values'].each do |flavor_name|
  execute "nova-manage flavor delete #{flavor_name}" do
    action :run
    only_if {flavors.include? flavor_name}
share|improve this question

Can you share your recipe? Unfortunately I can't find a reference, but I remember reading on the Opscode site that Chef runs Resources of the same type as a batch. So, how you are calling for the install (and the subsequent add/delete) can matter.

You may want to look at the Execute Resource

Chef documenation: sometimes you want to make sure that a resource is configured before anything else.

share|improve this answer
Updated the question with the code I'm using (fails on the first run because of missing nova-manage command) - the package is listed to install before, but the Chef::ShellOut runs before all resources. – viraptor Jan 4 '12 at 15:33

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