[chef] Retrieve contents of file between resources

[< >]

I'm attempting to modify the opscode-mysql cookbook to add support for the
MySQL 5.6 RHEL binaries.  Since MySQL 5.6.8, the RPM package install adds the
--random-password flag to mysql_install_db which generates a random password 
at
package install time and stores it in /root/.mysql_secret.  I need to parse 
the
file and extract the password *after* the package has been installed and pass
it into the execute["assign-root-password"] resource.

The file looks like this:

    # The random password set for the root user at Mon Mar 25 21:59:23 2013
(local time): abcdefg

I can extract the password with this (simplified) code:

    if ::File.file?('/root/.mysql_secret')
      initial_password =
::File.readlines(mysql_secret_file).grep(/random/).last.split(': ').last.chomp
    end
    initial_password_param = initial_password ? "-p#{initial_password}" : ""

Because chef executes ruby code before the resources are executed, I can't
figure out how to extract that temporary random password  after the package
install and pass it to execute[assign-root-password].

Ideally, I'd like to be able to do something like this:

    execute "assign-root-password" do
      command "\"#{node['mysql']['mysqladmin_bin']}\" -u root
#{initial_password_param} password
\"#{node['mysql']['server_root_password']}\""
      action :run
      only_if "\"#{node['mysql']['mysql_bin']}\" -u root
#{initial_password_param} -e 'show databases;'"
    end
 
I've thought about using a ruby_block, but I can't see a way to pass the
variable into the execute.

Hopefully this is more clear than mud.  Thanks in advance for any assistance!
Aaron