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Testing New Formulas

The formulae-contents that are installed and configured for use by Watchmaker can be modified through a custom config.yaml file. This is done through the config.yaml file’s user_formula dictionary-parameter (see: the discussion of the config.yaml file’s user_formulas parameter and take special note of guidance around file-formatting and indenting). This parameter may be used to enable the setup of new, yet-to-be integrated formulae[1]. This is done by specifying dictionary-values for user_formulas in a custom config.yaml file:



While multiple new formulae are shown in the above snippet, it’s not generally recommended to use this method for more than one, new formula at a time. The above is primarily to illustrate that the user_formulas parameter is a dictionary

Once the custom config.yaml file is in the desired state, it can be uploaded to an S3-based testing-bucket, web server[2] or even staged locally within the testing-system.

About Testing New Formulae

To the greatest extent possible, formulae should be portable. It is recommended that when testing updates, the developer:

  • Tests without use of a custom salt-content.zip

  • Tests using custom Pillar-data – either by hand-modifying Pillar content or using a modified salt-content.zip cloned from the target deployment-environments’ salt-content.zip – for one or more targeted deployment-environments

Exercising across environments, in this way, will better assure that newly-created formulae operate as portably as expected prior to the newly-created formulae’s integration into standard or site-specific Watchmaker executions.

Execution - Generic/Defaults

Assuming that the executing system has access to the specified URIs, watchmaker will:

  1. Download the requested formula ZIP-archive(s)

  2. Unarchive them to the .../formulas directory

  3. Update the .../minion file’s file_roots:base list

If the site’s salt-content.zip has not been modified to cause execution, the new formula can be explicitly executed using a method similar to:

  • Linux invocation:

    watchmaker \
      -c s3://<TESTING_BUCKET>/config.yaml \
      -s <FORMULA_NAME> \
      --log-level debug --log-dir=/var/log/watchmaker
  • Windows invocation:

    watchmaker --log-level debug --log-dir=C:\Watchmaker\Logs -c s3://<TESTING_BUCKET>/config.yaml -s <FORMULA_NAME>

The new formula’s execution will be logged into the directory requested via the manual invocation.

Execution - Tailored

If the new formula has variable configuration-data that needs to come from pillar, it will be necessary to either manually update the .../pillar directory’s contents with the appropiate data (see: The pillar Directory-Tree) or create a custom salt-config.zip file and reference it from the custom config.yaml file.

Final Notes

All formulae that have Pillar-settable or Pillar-overridable parameters should include a pillar.example or pillar.example.yaml file with the project’s content. This file should be placed in the project’s root-directory. The file should be valid YAML with explanatory comments for each configuration item. If a new formula’s execution-customizability is more complex than is easily accommodated by comment-entries in the example Pillar YAML file, add a README_PillarContents.md file to the project. This file should contain sufficiently-expository content to allow new users of the formula to fully understand how to tailor the formulae’s execution to their site’s needs.