[chef] Re: best way to run something only once?

[Ameir Abdeldayem < >]

Hi Tomasz,

Another thing you can do is touch a file in your bash code block, and in your bash resource, use 'creates'.  If the file is found, the code block will be skipped.

An example, from http://docs.opscode.com/chef/resources.html:

execute "upgrade script" do

  command "php upgrade-application.php && touch /var/application/.upgraded"

  creates "/var/application/.upgraded"

  action :run

end

More info:

https://tickets.opscode.com/browse/CHEF-3098

Thanks,

Ameir

On Wed, Jun 18, 2014 at 6:34 PM, Tomasz Chmielewski < " target="_blank"> > wrote:

Does chef have some built-in way to run some recipes (or parts of it)
once only?

Say, I have the following (here, bash snippet, but could be anything):

bash 'adjust-supervisor' do
  code <<-EOF
     ...some_code...
  EOF
end


How would you approach to make sure it only runs once?

I figured I could use something like this in the recipe:

   not_if { ::File.exists?("/etc/chef/stamps/some-description.stamp") }

followed by:

file "/etc/chef/stamps/some-description.stamp" do
  owner "root"
  group "root"
  mode "0644"
  action :create
end


It allows me to easily re-run by removing the stamp file, if needed.


But not sure it's the optimal way to make sure we run a given thing
once.

How do you approach this?




--
Tomasz Chmielewski
http://www.sslrack.com