Create chef recipe by passing values dynamically, from properties file

chefchef-soloruby

I created a chef recipe which has the installation of a specific rpm mentioned in it. This rpm has a version number which needs to be loaded dynamically from a properties file (which is itself created dynamically). This chef recipe then needs to be loaded into the chef server.

remote_file "Core_feature.rpm" do
path   "#{src_loc}core_feature_v91-2.noarch.rpm"

Here, v91-2 is the value which needs to go in dynamically into the recipe, by reading from a properties file.

Is this achievable? If yes, how do I go on to implement it.(Have no idea on ruby)!

Best Answer

Edit: complete rewrite due to down-voting but without more information I'm not sure what exactly I'm correcting so here is working code that can be copied and pasted.

Assuming contents of properties file placed in /tmp/versions.properties and looks like the following:

apache=2.4.7-1ubuntu4.8
php=5.4.3
sendmail=1.2.3

Chef Cook book

# Copy a file with versions
cookbook_file '/tmp/versions.properties' do
  source 'versions.properties'
  mode '0644'
end

# Setvar
node.default['version'] = ""

# Block where we set the command
ruby_block "set_app_id" do
  block do
     node.set['version'] = "apt-get install apache2=`grep -o 'apache=.*' /tmp/versions.properties | cut -f2- -d'='`"
  end
  action :create
end

# Do a lazy install
execute "install lazy based" do
    command lazy {node[:version]}
end

As a bonus option if you are working strictly on *nix the following works without lazy:

# Execute straight up
 execute "install lazy based" do
    command "apt-get install apache2=`grep -o 'apache=.*' /tmp/versions.properties | cut -f2- -d'='`"
 end

I still used the original premise of the links in the first two posts referenced:

Assuming that properties file is on the server(?) you could use lazy evaluation as described [in this post][1]

Edit: Check this [one out too][2]

[1]: https://stackoverflow.com/questions/26238056/setting-chef-variable-via-a-ruby-block-not-being-executed. [2]: https://stackoverflow.com/questions/20620724/how-to-lazily-evaluate-an-arbitrary-variable-with-chef

Related Solutions

Setting properties in chef-client.rb

Fyi: The default config file is /etc/chef/client.rb, you would need to pass -c /etc/chef/chef-client.rb to use that file.

To set theChef configuration settings for http proxy, you can set the proxy to use with knife bootstrap with the command-line option --bootstrap-proxy URL. Or, you can add this in in your knife.rb.

knife[:bootstrap_proxy] = "https://proxy.example.com"

Replace the "https://proxy.example.com" value with your proxy server URL.

This will add the http_proxy and https_proxy lines to the /etc/chef/client.rb file automatically. Alternatively, you can create a customized bootstrap template with these configuration values in the client config section. Something like this (modified from ubuntu10.04-gems.erb):

(
cat <<'EOP'
http_proxy "http://proxy.example.com" # replace with your URL
<%= config_content %>
EOP
) > /etc/chef/client.rb

Prevent chef recipe from executing previously executed action

This is generally the method I use, especially if the command you take results in a file being created as a side effect For example disabling or enabling sites in Debian's apache2 package removes or creates links in /etc/apache2 which you can test for using File.exists?.

A trick is to set an attribute after the execute resource has run:

if !node["did_test"]
  execute "test" do
    command "touch /tmp/foo"
  end
end

ruby_block "did_test" do
  block do
    node.normal["did_test"] = true
  end
end

Note that it's still possible for the execute resource to be run twice in some situations so this technique isn't perfect, but you can now use knife-search to determine which nodes have performed the execute.

Best Answer

Related Solutions

Setting properties in chef-client.rb

Prevent chef recipe from executing previously executed action

Related Topic