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Mojo
Asked: 2015-09-17 09:03:55 +0800 CST

How to reference a hiera variable from elsewhere the hierarchy?

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So suppose in a very specific hiera YAML file I define a variable, such as "env_name".

env_name: "dev-unstable"

Now in a more general hiera file I'd like to interpolate that variable into a string.

server_name: "service-%{env_name}.%{::domain}"

My testing seems to imply that hiera variables from elsewhere in the hierarchy aren't made available for interpolation in general cases. Is that true, unfortunately?

puppet

3 Answers

  1. Best Answer

    You can use Hiera lookup functions within Hiera. Documentation here: https://docs.puppetlabs.com/hiera/1/variables.html#using-lookup-functions

    In your case you would use:

    server_name: "service-%{hiera('env_name')}.%{::domain}"

    This is a priority lookup and will get the value for the key env_name from the highest (most specific) hierarchy level in which it finds the key.

    This requires Hiera 1.3 or higher.

    • 5

  2. For Hiera 5, used in Puppet 5, use the following syntax:

    server_name: "service-%{lookup('env_name')}.%{::domain}"

    ...where %{lookup('env_name')} is the part that gets the data from other hiera key.

    (Source)

    • 4

  3. See the answer from Greg Dubicki.

    To quote "The hiera, hiera_array, hiera_hash, and hiera_include functions are all deprecated. The lookup function is a complete replacement for all of these."

    For details see:

    https://puppet.com/docs/puppet/5.5/hiera_migrate.html#updated_classic_hiera_function_calls

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