Application-level Goss checks

[MichaelThamm]

This PR provides more complexity and explores the capabilities of Goss rather than usage workflows and architecure discussed in the solution-level Goss checks PR.

PR Highlights

• application-level Goss checks.
  • The goss.yaml files exist in the same location as the application i.e. grafana-k8s-operator
• fetch goss files from decentralised locations.
  • Allows for dynamically combining goss checks for deployments and applications.
  • For example:
    1. start with an empty dir
    2. fetch-subdir solution-level checks
    3. fetch-subdir multiple application-level checks
    4. goss validate

Workflow

Fetching a sub-directory with Git is not a simple one-line command and is simplified with this fetch-subdir.sh script. This script can be executed anywhere with context to git and is not limited to this PR. We will use this script for the following examples:

Note:
<arbitrary_dir> = any dir,
<grafana_dir> = this cloned repo

Note: <grafana_dir>/fetch-subdir.sh exists in this PR for demo purposes but in the final solution will be included in the Juju plugin or juju-doctor snap.

1. cd <arbitrary_dir>
2. org="https://github.com/canonical"; repo="grafana-k8s-operator"; branch="feature/goss"; dir="goss"
3. source <grafana_dir>/goss/fetch-subdir.sh "$org" "$repo" "$branch" "$dir"

Run application-level checks

3. goss -g "$repo/goss/goss.yaml" --vars-inline '{"goss_dir": "'"$repo/goss"'"}' validate -f documentation

Expected result: Count: 6, Failed: 0, Skipped: 0

Inherit goss checks and run all

Note: These steps assume you already have some goss-*.yaml files in the <arbitrary_dir>/goss dir and the associated juju deployment. If not, use cos-lite-bundle as an example.

3. cp -ru $repo/goss/* goss/
4. goss -g goss/goss.yaml --vars-inline '{"goss_dir": "goss"}' validate -f documentation

Expected result: Count: >6, Failed: 0, Skipped: 0