# Tencent Cloud Private Registry Design

**Goal:** Add CI that automatically builds and pushes private `backend` and `frontend` images to a self-hosted Docker Registry running on a Tencent Cloud CVM, with `dev` publishing test tags, `release` and `release/*` publishing release-candidate tags, and `main` publishing formal tags.

**Decisions**
- Publish only two runtime images: `<registry-host>/ctms/ctms-backend` and `<registry-host>/ctms/ctms-frontend`.
- Keep the private registry on the Tencent Cloud CVM as a self-hosted `registry:2` instance protected by `htpasswd`.
- Trigger automation on pushes to `dev`, `release`, `release/*`, and `main`.
- Use GitHub Actions only as the orchestrator. Actual Docker build and push happen on the Tencent Cloud server over SSH.
- Keep `docker-compose.yaml` compatible with both local `build` workflows and private registry pulls.

**Approaches Considered**
- Recommended: GitHub Actions connects to the Tencent Cloud server over SSH and runs a server-local build-and-push script. This avoids GitHub-hosted runner limitations around insecure or self-signed private registries and keeps registry access local to the server.
- Alternative: GitHub Actions builds and pushes directly to `<IP>:5000`. This is simpler on paper but is fragile when the registry is exposed only as an IP endpoint and may use insecure or non-public TLS.
- Alternative: move first to a domain-backed HTTPS registry and then push directly from GitHub Actions. This is the clean long-term path but adds infrastructure work that is not required for the current goal.

**Architecture**
- A new GitHub Actions workflow triggers on pushes to `dev`, `release`, `release/*`, and `main`.
- The workflow authenticates to the Tencent Cloud server using SSH credentials stored in GitHub Secrets.
- The workflow syncs the repository contents to a fixed build directory such as `/opt/ctms-build/<repo>`.
- A server-local script logs in to the private registry, builds `backend` and `frontend`, applies branch-specific tags, and pushes the images to the registry.

**Registry Naming**
- Backend image: `<registry-host>/ctms/ctms-backend`
- Frontend image: `<registry-host>/ctms/ctms-frontend`

**Tagging Strategy**
- `dev` branch pushes publish:
  - `<registry-host>/ctms/ctms-backend:dev-latest`
  - `<registry-host>/ctms/ctms-backend:dev-<short_sha>`
  - `<registry-host>/ctms/ctms-frontend:dev-latest`
  - `<registry-host>/ctms/ctms-frontend:dev-<short_sha>`
- `release` branch pushes publish:
  - `<registry-host>/ctms/ctms-backend:rc-release`
  - `<registry-host>/ctms/ctms-backend:rc-<short_sha>`
  - `<registry-host>/ctms/ctms-frontend:rc-release`
  - `<registry-host>/ctms/ctms-frontend:rc-<short_sha>`
- `release/*` branch pushes publish:
  - `<registry-host>/ctms/ctms-backend:rc-<release-branch>`
  - `<registry-host>/ctms/ctms-backend:rc-<short_sha>`
  - `<registry-host>/ctms/ctms-frontend:rc-<release-branch>`
  - `<registry-host>/ctms/ctms-frontend:rc-<short_sha>`
- `main` branch pushes publish:
  - `<registry-host>/ctms/ctms-backend:latest`
  - `<registry-host>/ctms/ctms-backend:sha-<short_sha>`
  - `<registry-host>/ctms/ctms-frontend:latest`
  - `<registry-host>/ctms/ctms-frontend:sha-<short_sha>`

**Server Requirements**
- Docker installed on the Tencent Cloud server.
- A private `registry:2` instance listening on `<IP>:5000`.
- `htpasswd` authentication configured for the registry.
- SSH access from GitHub Actions to the server.
- A writable build directory such as `/opt/ctms-build`.

**GitHub Secrets**
- `TCLOUD_HOST`
- `TCLOUD_PORT`
- `TCLOUD_USER`
- `TCLOUD_SSH_KEY`
- `REGISTRY_HOST`
- `REGISTRY_USERNAME`
- `REGISTRY_PASSWORD`

**Compose Integration**
- `docker-compose.yaml` should define `image:` for `backend`, `backend-init`, and `frontend`, with defaults based on private registry variables such as `REGISTRY_HOST`.
- Existing `build:` blocks stay in place so local `docker compose up -d --build` continues to work.
- Deployment hosts can export `REGISTRY_HOST`, then run `docker login`, `docker compose pull`, `docker compose run --rm backend-init`, and `docker compose up -d`.

**Operational Notes**
- This design assumes the server-local script runs on the same machine that can log in to the private registry reliably.
- The GitHub workflow should not embed long shell logic inline; the repository should own a script under `scripts/` so the build logic stays versioned and testable.
- Direct verification of actual image publication depends on GitHub Actions reaching the Tencent Cloud server and cannot be proven locally without those secrets and network access.

**Verification**
- Push to `dev` and confirm both images appear with `dev-latest` and `dev-<short_sha>`.
- Push to `release` and confirm both images appear with `rc-release` and `rc-<short_sha>`.
- Push to `release/*` and confirm both images appear with `rc-<release-branch>` and `rc-<short_sha>`.
- Push to `main` and confirm both images appear with `latest` and `sha-<short_sha>`.
- Run `docker compose config` after compose changes and confirm the private registry defaults render correctly.
- Parse the workflow YAML successfully and inspect the remote build script for the expected tag logic and registry login behavior.