OSP: literal function and braces

[halfninja]

Describe the Change You Would Like

The documentation for the Hiera literal function says this:

This is useful when dealing with Apache config files, for example, which might include text such as %{SERVER_NAME}. For example:

server_name_string: "%{literal('%SERVER_NAME')}"

The latter example works fine - the issue is with "such as %{SERVER_NAME}". A reasonable reader would then expect to be able to do this:

server_name_string: "%{literal('%{SERVER_NAME}')}"

but it fails (tested in Hiera from Puppet 8.6.0):

Syntax error in string: %{literal('%{SERVER_NAME}')}

This may be as expected behaviour but in that case the documentation should demonstrate how to work around this, such as

server_name_string: "%{literal('%')}{SERVER_NAME}"

[joshcooper]

Thanks @halfninja that makes sense. I'm going to transfer this to the puppet-docs repo to get that updated.

[joshcooper]

How about:

- for example, which might include text such as `%{SERVER_NAME}`. For example:
+ for example, which might need to contain the string `%{SERVER_NAME}`. In order to accomplish this, you'll need to remove the braces and use the `literal` function, for example: 

And then have the code block follow:

server_name_string: "%{literal('%SERVER_NAME')}"

[halfninja]

Suppose it depends if the target supports the form without braces. I guess httpd does but others might not.

I actually started using this for Logback config to output things like %mdc{trace_id} until I realised that this particular syntax doesn't trigger Hiera's interpolation and can be written as-is, I guess because the % and the { are separated.

[github-actions]

Migrated issue to PUPDOC-5705