[Resolves #813] Fix nested config Jinja render

[lucasvieirasilva]

This PR fixes nested config.yaml jinja substitutions (e.g {{ someKey }}).

Fixes issue: #813

Scenario

Currently, when the project structure has multiple nested config files and one of them tries to use a property from another config file sometimes works, and sometimes not, when not work the error message is <prop> is undefined..

Example structure:

root/
  config/
    prod/
      A.yaml
      config.yaml
      2/
        B.yaml
        config.yaml
        3/
          C.yaml
          config.yaml

config/prod/config.yaml

keyA: A

config/prod/2/config.yaml

keyB: {{ keyA }}-B

config/prod/2/3/config.yaml

keyA: {{ keyB }}-C

keyB should render the value A-B and keyC should render the value A-B-C

When running sceptre launch prod command the ConfigReader class doesn't follow a correct order to process the files, and sometimes the config object already has all the properties, sometimes not.

Solution

Sceptre already has a concept of recursive read in the ConfigReader class that reads all the config.yaml files recursively based on the parent path, and already has the config dict object with all the properties in the correct place, but when call the _render function just pass the stack_group_config that only contains the processed stack_group_config, which is fine when the files follow the correct order to be processed.

However, if the ConfigReader combines the current recursive object with the stack_group_config the _render will have all the required properties, doesn't matter which file order will be used to process the stacks.

PR Checklist

• Wrote a good commit message & description [see guide below].
• Commit message starts with [Resolve #issue-number].
• Added/Updated unit tests.
• Added/Updated integration tests (if applicable).
• All unit tests (make test) are passing.
• Used the same coding conventions as the rest of the project.
• The new code passes pre-commit validations (pre-commit run --all-files).
• The PR relates to only one subject with a clear title.
  and description in grammatically correct, complete sentences.

Approver/Reviewer Checklist

• Before merge squash related commits.

Other Information

Guide to writing a good commit

[zaro0508]

Does this also fix issue #937 ?

[lucasvieirasilva]

Does this also fix issue #937 ?

No, it is a different issue.