[chef-dev] Re: Any equivalent of "puppet augeas" in Chef?

[Joseph Holsten < >]

On 2013-09-16, at 06:11, 

 
 wrote:

> I need to do in-place file editing of config files using Chef. For now, i 
> could
> see that we can append data to the config files using the "bash" resource. 
> But,
> i need to change specific variables in config files using Chef.
> 
> I could see that there's a handy tool called augeas in puppet that clearly
> performs the above requirement. But, i couldn't come up with anything in 
> Chef.
> 
> So, is there any way this could be done in Chef?

There isn't an augeas resource provided by chef, and cursory searching 
doesn't reveal a cookbook with one. But you could certainly write one. Here's 
some inspiration:

Salt provides an augeas 'state' (like resource) with one 'command' (like 
action): setvalue. It also provides a 'module' (like library) that supports 
get, ls, match, remove, setvalue & tree.
    http://docs.saltstack.com/ref/modules/all/salt.modules.augeas_cfg.html
    http://docs.saltstack.com/ref/states/all/salt.states.augeas.html

Puppet has very thorough complete doc for using the augeas 'type' (like 
resource) in puppet:
    http://projects.puppetlabs.com/projects/puppet/wiki/Puppet_Augeas
    http://docs.puppetlabs.com/references/latest/type.html#augeas

I'd like to see a chef resource that does things like:

    augeas '/files/etc/ssh/sshd_config/AcceptEnv/01' do
      value 'FOO'
      action :set
    end
    
    augeas 'accept foo env in sshd' do
      path '/files/etc/ssh/sshd_config/AcceptEnv/01'
      value 'FOO'
      action :set
    end
    
    augeas "/files/etc/ssh/sshd_config/AcceptEnv/01" do
      action :rm
    end

Looks like there are some decent augeas bindings in ruby-augeas:
    https://github.com/hercules-team/ruby-augeas

I think you could get dangerously far with something like

    require 'ruby-augeas'
    
    action :set do
      Augeas::open do |aug|
        aug.set(new_resource.path, new_resource.path)
        unless aug.save
          raise IOError, "Failed to save changes"
        end
      end
      new_resource.updated_by_last_action(true)
    end
    
    action :rm do
      Augeas::open do |aug|
        aug.rm(new_resource.path)
        unless aug.save
          raise IOError, "Failed to save changes"
        end
      end
      new_resource.updated_by_last_action(true)
    end

I'd still want a recipe to install augeas and the ruby-augeas gem, plus some 
actual error handling, really checking if the resource was updated, and 
converge_by/why-run support would be awesome.
--
~j

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