feat: Add Confluence as BigBang Addon
# Feature Request
## Why
Confluence is part of the PartyBus baseline.
## Proposed Solution
Create a Confluence helm chart [here](https://repo1.dso.mil/platform-one/big-bang/apps/collaboration-tools/confluence). Tag it with an approved release, and implement it into BigBang.
## Definition of Done
**Package:**
* [ ] Do you have a 'main' branch that is default and protected?
* [ ] Are all other branches merged or deleted? For master and dev branches, tag the branch commit before deleting the branch so we can retrieve it if necessary. Exception: branches labeled release
* [ ] Does the repo contain only the following directories: chart, docs, tests? All other directories should be deleted.
* [ ] Is there a CODEOWNERS file containing some code owners?
* [ ] Is there a CHANGELOG.md file with initial changes?
* [ ] Is there a README.md file documenting basic use?
* [ ] Is there a CONTRIBUTING.md file outlining how a new person can contribute?
* [ ] Is there a .gitlab-ci.yml pipeline setup pointing to a pipeline template?
* [ ] Is there a tests/test-values.yaml file setup to provide default values for the pipeline? This must include image pull secret references.
* [ ] Is there a chart/Kptfile that points to the upstream chart used in the repo? Exception: Not needed if upstream chart is not used.
* [ ] Does the upstream chart version deploy the application version used in Iron Bank (or as close as possible)? This will help avoid incompatible configuration settings.
* [ ] Have you run helm dep up and added all .tgz file depedencies in chart/charts to the repo?
* [ ] Have you updated chart/requirements.yaml or chart/Chart.yaml to point to the file://./charts/.tgz dependencies?
* [ ] If the chart has a web interface, have you added a VirtualService using hostname that is conditionally added if istio.enabled is true? Verify this works using the web address.
* [ ] If the chart integrates with Prometheus monitoring, have you added a Service and ServiceMonitor that are conditionally added if monitoring.enabled is true? Verify this using Prometheus to check targets.
* [ ] Does your package have resource requests and limits set and equal to each other?
* [ ] Do you have a tag on your main branch for the Big Bang release version of the package?
* [ ] Have all of your images been updated to pull from registry1.dso.mil. Exception: If there is no Iron Bank image, are you pulling from registry.dso.mil?
* [ ] If the package supports SSO, have you integrated SSO settings? Needs clarification
* [ ] If the package requires a database, have you integrated external database settings? Needs clarification
* [ ] If the package requires storage, have you ingegrated external storage (e.g. MinIO) settings? Needs clarification
* [ ] Are all secrets and certificates removed from the repo? All secrets should be references or randomly generated during deployment.
**Big Bang:**
* [ ] Have you added a namespace.yaml in chart/templates that sets up the package's namespace
* [ ] Have you added pull secret creation to a resource? This may be in the namespace.yaml file.
* [ ] Have you added a gitrepository.yaml in chart/templates that sets up a flux GitRepository resource pointing to the package's git repository?
* [ ] Have you added a helmrelease.yaml in chart/templates that sets up a flux HelmRelease resource pointing to the package's helm chart?
* [ ] Have you added default values to the HelmRelease that need to be passed downstream to the package? For example: hostname, istio.enabled, monitoring.enabled.
* [ ] Have you added image pull secret references to the HelmRelease to be passed downstream to the package?
* [ ] Have you added other package dependencies to the HelmRelease to insure deployment order?
* [ ] Have you added a key for .yaml into chart/templates/values.yaml so override values can be passed downstream to the package?
* [ ] Have you added a valuesFrom configuration in the HelmRelease pointing to the values secret with a valuesKey equal to .yaml?
* [ ] Have you added the package into chart/values.yaml under addons? Exception: core apps do not go under addons.
* [ ] Have you added enabled: false to your chart/values.yaml and conditional statements on enabled: true for your namespace, pull secret, git repository, and helm release?
* [ ] Have you added git repo configuration to chart/values.yaml pointing to the packages git repo, helm chart path, and tag.
* [ ] Have you added a values: {} placeholder for you package in chart/values.yaml?
* [ ] Have you added any applicable default values from Fences and Party Bus to the package? Exception: Infrastructure specific implementations (e.g. AWS)
* [ ] Have you verified that
Additional details on definition of done need to be added for:
* Database integration
* Storage (minio) ingegration
* Certificates?
* SSO integration
**Testing:**
* [ ] Have you verified the CI/CD pipeline passes?
* [ ] Have you verified the application is available via web URL (if applicable)?
* [ ] Have you verified you can login via SSO with your Platform One account (if applicable)?
* [ ] Have you verified you Prometheus is scraping data from monitoring endpoints on the application (if applicable)?
* [ ] Have you verified the application has database connectivity to the external database (if applicable)?
* [ ] Have you verified the application has storage connectivity to the external storage (if applicable)?
## Future Work (as separate issues)
- [ ] SSO is integrated as BigBang values
epic