How openstack-k8s-operators/ci-framework works
<explanation>
1. Project type and purpose
- This is a highly modular, Ansible‑based CI framework (“ci‑framework”) designed to orchestrate, test, and validate OpenStack/Kubernetes operator deployments and related infrastructure via Ansible playbooks, roles, Molecule scenarios, Zuul pipelines, container builds, and documentation.
2. High‑level architectural components
a. CI Orchestrator Layer
‑ Zuul pipelines (zuul.d/*.yaml) triggered by GitHub or Gerrit events
‑ GitHub Actions/CodeQL for code scanning
b. Execution Engine
‑ Ansible core (ansible.cfg) driving:
• Playbooks (playbooks/, ci/playbooks/, cleanup-edpm.yml, update-edpm.yml)
• Roles library (roles/*) with defaults, tasks, handlers, meta, molecule tests
• Plugins (plugins/action, filter, module_utils, modules) extending Ansible
‑ Molecule for role/unit/integration testing (roles/*/molecule/*, tests/*)
‑ Container tooling: Podman/Docker (containerfiles/, roles/build_containers, roles/build_push_container)
c. Underlying Infrastructure/Test Targets
‑ Virtualization & networking: libvirt_manager
‑ Kubernetes/OpenShift clusters (openstack operators, kuttl)
‑ Baremetal/network appliances (nat64_appliance, virtualbmc, ironic, hive)
‑ Storage (ceph via cifmw_cephadm, lvms, local_storage)
d. External Services & Repositories
‑ Container registries (quay.io, mirrored via roles/mirror_registry)
‑ GitHub/Gerrit code hosts
‑ ReadTheDocs for documentation (docs/source)
‑ ReportPortal or other test-report aggregators (roles/reportportal)
3. Relationships and interactions
- GitHub/Gerrit event → Zuul orchestrates a pipeline → launches one or more Ansible jobs
- Ansible Execution Engine reads CI playbooks → loads roles, plugins → orchestrates:
• Container build & push → container registry
• Infrastructure setup (libvirt VMs, baremetal via Ironic & virtualbmc)
• Deploy OpenStack/K8s operators via kustomize/oc commands
• Run tests (Molecule, kuttl, Tempest, Tobiko)
• Collect artifacts & logs → archive or reportportal
- Molecule tests isolate individual roles in ephemeral Docker/Podman environments
- Documentation build via Sphinx reads docs/source → published to ReadTheDocs
4. Architectural patterns & principles
- Modular, plug‑in architecture: roles, modules, filter/action plugins
- Separation of concerns:
• Orchestration (playbooks + scenarios)
• Reusable building blocks (roles)
• CI pipelines (Zuul + GitHub Actions)
• Testing & validation (Molecule + integration tests)
• Container build & artifact publishing
- Scalability via scenarios directory driving multi‑node or multi‑service configurations
5. Tailoring your system diagram
- Use a layered view:
Layer 1: CI Orchestration (Zuul, CodeQL, GitHub Actions)
Layer 2: Execution Engine (Ansible, Molecule, Podman)
Layer 3: Roles & Playbooks repository (roles/, playbooks/, plugins/)
Layer 4: Target environments (libvirt VMs, Kubernetes clusters, Baremetal nodes, Storage backends)
Layer 5: External systems (Container registries, Git repos, Documentation service, ReportPortal)
- Show data/control flows: e.g., “Zuul → Ansible Runner → Target Infrastructure → Test Results → Zuul/ReportPortal”
6. Diagram elements to include
- Components as labeled boxes (use different shapes or colors):
• CI Orchestrator (cylinder or cloud icon)
• Ansible Engine (rectangle)
• Roles & Plugins (stacked rectangles)
• Molecule Test Harness (rectangle with dashed boundary)
• Container Registry (cylinder)
• Infrastructure Targets (grouped icons for VMs, Kubernetes, Baremetal)
- Arrows with direction and labels indicating:
• “Trigger”, “Deploy”, “Test”, “Collect Artifacts”, “Publish”
- Color coding:
• Blue for control components (Zuul, Ansible)
• Green for target environments
• Orange for repositories/registries
• Gray for supporting services (ReadTheDocs, ReportPortal)
7. Additional guidelines
- Be exhaustive in identifying roles subsets: grouping related roles under “Storage”, “Networking”, “Operator Deployment”, etc.
- Depict Molecule’s ephemeral environment as a side branch of the Ansible Engine, emphasizing test isolation
- Highlight custom plugins (action, filter, module_utils) as extension points in the Ansible Engine layer
- Keep the diagram uncluttered by grouping hundreds of roles into logical domains
By following these steps, you’ll capture the essential architecture of the CI‑Framework: the CI orchestration, the Ansible‑based execution engine with its modular roles and plugins, the testing harness, the underlying infrastructure targets, and the external services it integrates with. Ensure all components, their interactions, patterns, and technologies are clearly labeled and color‑coded for immediate comprehension.