---
status: accepted
date: 2026-04-30
decision-makers: R&D Lead
tags: [infrastructure, process]
---

# CI/CD pipeline — Gitea Actions, trunk-based + squash-merge, thin YAML over portable scripts

## Context and Problem Statement

The repository currently lives on Gitea (`gitea@git.unespace.com:julien/adastra_portal.git`). The organisation plans to migrate to GitLab on a 6–18-month horizon. The pipeline shape we adopt now must be (a) operational on Gitea immediately, (b) low-cost to migrate later, and (c) consistent with the project's anti-bricolage and security-first values.

We also need to fix the branch model, the merge strategy, the required gates, the protection rules on `main`, and the location of the orchestration logic — all of these have first-order effects on the Nx scaffold (`package.json` scripts, lint configs, branch tags, conventional-commits validation surface).

This ADR is split into two levels of decision:
- **Level 1 — vendor-neutral.** Survives the future GitLab migration unchanged.
- **Level 2 — Gitea Actions implementation.** Will be rewritten when GitLab is adopted; a future ADR will supersede the level-2 sections without affecting level-1.

## Decision Drivers

* Pipeline portability across CI vendors (Gitea now, GitLab later, possibly other platforms in the future).
* All gates blocking — no "warnings ignored". Either we fail or we adjust the threshold via ADR.
* Trunk-based development for fast feedback and continuous integration discipline.
* Compatibility with the Nx monorepo's `affected` model and remote cache.
* Self-hosted runners (on-prem context — see ADR-0008's hosting constraint).
* Mature, mainstream tooling — anti-bricolage applies particularly here.
* Local enforcement (Husky + lint-staged + commitlint, ADR-0007) plus CI defense in depth — the same checks run twice, on purpose.

## Considered Options

### Branch / merge strategy (level 1)
* **Trunk-based + squash-merge.** (Chosen.)
* Trunk-based + rebase-merge.
* Trunk-based + merge commit.
* GitFlow.

### Required reviewer count on PRs to `main` (level 1)
* **0 in v1, ≥1 once a second active contributor exists.** (Chosen.)
* 1 always (blocks if solo).
* 2 (heavy for a small team).

### Signed commits (level 1)
* **Recommended but not required in v1; reconsidered at the GitLab migration ADR.** (Chosen.)
* Required in v1.
* Never.

### Conventional Commits validation (level 1)
* **Local `commit-msg` hook (ADR-0007) + CI defense-in-depth on the PR commit range.** (Chosen.)
* Local hook only.
* CI only.

### Pipeline orchestration logic location (level 1)
* **Thin YAML — logic lives in `package.json` scripts and Nx targets, the workflow file orchestrates.** (Chosen.)
* Logic in YAML, scripts called step by step.

### CI engine (level 2 — Gitea-specific)
* **Gitea Actions** (built-in since Gitea 1.19, GitHub Actions-compatible YAML). (Chosen.)
* Drone CI alongside Gitea.
* Concourse / Tekton / Buildkite / etc.

### Runner topology (level 2)
* **≥ 3 self-hosted `act_runner` instances on-prem.** (Chosen.)
* Single runner.
* Cloud-hosted (rejected — on-prem constraint).

## Decision Outcome

### Level 1 — vendor-neutral decisions

**Branch model.** Trunk-based with `main` always deployable. Feature branches are short-lived (hours to days), named `feat/<short-slug>` or `fix/<slug>` or `chore/<slug>`. Releases happen by tagging `vX.Y.Z` on `main`.

**Merge strategy.** Squash-merge only. The squash subject is the PR title and must be a valid Conventional Commits message; the squash body inherits the PR body. This produces a clean linear history on `main` where each commit corresponds 1:1 to a PR. Rebase-merge and merge-commit are disabled at the platform level.

**Branch protection on `main`:**
- direct push: forbidden (no exceptions, including the project lead);
- force push: forbidden;
- linear history: required (consistent with squash-merge);
- required status checks: every CI gate listed below, all blocking;
- required PR review approvals: 0 in v1 (solo), revisited to ≥1 once a second active contributor joins (a follow-up ADR or amendment will mark the date);
- branch deletion after merge: required;
- merge of stale branches: PRs must be up-to-date with `main` before merging (or use a merge queue once GitLab provides one).

**Required CI gates** (every gate is blocking; failing any blocks the merge):

| Gate | What it runs | Tooling |
| --- | --- | --- |
| `format` | Prettier check, no auto-fix | `prettier --check` via `pnpm nx format:check` |
| `lint` | ESLint across affected projects, including `@nx/enforce-module-boundaries` | `pnpm nx affected -t lint` |
| `type-check` | TypeScript strict, no emit | `pnpm nx affected -t type-check` |
| `test` | Unit/component tests | Vitest (front, ADR-0004) and Jest (back, ADR-0005), via `pnpm nx affected -t test` |
| `build` | Production builds of affected apps and libs | `pnpm nx affected -t build` |
| `audit` | Dependency vulnerabilities | `pnpm audit` + Trivy filesystem scan |
| `secret-scan` | Repo-wide secret detection | `gitleaks` |
| `commit-lint` | Conventional Commits validation on the PR commit range | `commitlint --from <base> --to HEAD` |
| `a11y` | Pending — defined by future a11y ADR (axe-core in e2e) | (placeholder) |
| `perf` | Pending — defined by future perf ADR (Lighthouse CI) | (placeholder) |

**Conventional Commits.** Already enforced locally via the `commit-msg` hook (ADR-0007). In CI, `commitlint --from origin/main --to HEAD` runs against the PR commit range as defense in depth — even if a contributor bypasses the local hook, the CI gate catches it.

**Signed commits.** Recommended but not required in v1. Setup overhead for contributors (GPG or SSH signing key) is non-trivial relative to the marginal value with a single contributor and a well-controlled host. The decision is revisited as part of the GitLab migration ADR (GitLab has stronger built-in tooling for centralised signing policies than current Gitea).

**Logic location — the "thin YAML" pattern.** All non-trivial CI logic lives in `package.json` scripts and Nx targets, *not* in the workflow YAML. The YAML's role is restricted to: checkout, runtime setup, cache restoration, and calling a single high-level script per job. Concretely:

```jsonc
// package.json (excerpt — lands with the scaffold)
"scripts": {
  "ci:check":   "pnpm exec nx affected -t format:check lint type-check test build",
  "ci:scan":    "pnpm audit --audit-level=moderate && pnpm exec trivy fs --skip-dirs node_modules --exit-code 1 . && pnpm exec gitleaks detect --no-banner --redact",
  "ci:commits": "pnpm exec commitlint --from $COMMIT_LINT_FROM --to HEAD --verbose"
}
```

The migration to GitLab then becomes a rewrite of the YAML wrappers (a few dozen lines) and not a re-derivation of the gates — these scripts are platform-agnostic, runnable locally, and serve as the source of truth.

**Caching.** Two cache surfaces, both portable:
- the `pnpm` store, keyed on `pnpm-lock.yaml`;
- the Nx local cache (`.nx/cache`), keyed on the project graph.

The level-2 implementation wires both via the CI vendor's cache action; the level-1 contract is "these two paths must be cached".

**Secrets policy.**
- Secrets live exclusively in CI vendor variables (Gitea → GitLab later). Naming convention: `SCOPE_PURPOSE` (e.g. `BFF_DATABASE_URL`, `OBO_CACHE_ENCRYPTION_KEY`).
- No secret ever in source. `gitleaks` enforces.
- Rotation procedures, key vault, and operator runbooks belong in the future operations / secret-management ADR.

**Container images / deployment.** Explicitly out of scope of this ADR. CI v1 builds and tests; image build and deploy will land with the on-prem infrastructure ADR (phase 3).

### Level 2 — Gitea-specific implementation

**Engine.** Gitea Actions, available since Gitea 1.19. The workflow YAML is GitHub Actions-syntax-compatible, which means most third-party actions (`actions/checkout`, `actions/setup-node`, `pnpm/action-setup`, etc.) work unchanged. This compatibility is also a partial migration hedge: the same workflows can be ported to GitHub Actions with near-zero changes if the org pivots to GitHub instead of GitLab.

**Runners.** Three self-hosted `act_runner` instances on internal infrastructure. The first runner is deployed to validate the pipeline; the second and third are added before the project hits any non-trivial PR volume. Runners are labelled `self-hosted`, `on-prem`, plus capacity labels (`size:default`) for future job differentiation. Runner image baseline: a Debian image (aligned with the WSL development environment) pinned by SHA and rebuilt on a cadence by a security-scheduled job.

**Workflow file structure.**
- `.gitea/workflows/ci.yml` — runs on `pull_request` and `push` to `main`. Hosts the `check`, `scan`, and `commits` jobs.
- `.gitea/workflows/release.yml` — runs on `push` of a `vX.Y.Z` tag. Builds release artefacts. Empty stub in v1; gains content when the on-prem deploy ADR lands.
- `.gitea/workflows/security-scheduled.yml` — runs weekly via `schedule:` cron. Re-runs Trivy and gitleaks on the full tree (not just affected), and triggers Renovate (configuration covered by the security baseline ADR).

Three files; small surface; clear scope per file.

**Workflow shape (illustrative — final lands with the scaffold):**

```yaml
# .gitea/workflows/ci.yml
name: CI
on:
  pull_request:
    branches: [main]
  push:
    branches: [main]

jobs:
  check:
    runs-on: [self-hosted, on-prem]
    steps:
      - uses: actions/checkout@v4
        with: { fetch-depth: 0 }
      - uses: nrwl/nx-set-shas@v4
      - uses: pnpm/action-setup@v3
      - uses: actions/setup-node@v4
        with: { node-version-file: '.nvmrc', cache: pnpm }
      - run: pnpm install --frozen-lockfile
      - run: pnpm ci:check
  scan:
    runs-on: [self-hosted, on-prem]
    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v3
      - uses: actions/setup-node@v4
        with: { node-version-file: '.nvmrc', cache: pnpm }
      - run: pnpm install --frozen-lockfile
      - run: pnpm ci:scan
  commits:
    if: github.event_name == 'pull_request'
    runs-on: [self-hosted, on-prem]
    steps:
      - uses: actions/checkout@v4
        with: { fetch-depth: 0 }
      - uses: pnpm/action-setup@v3
      - uses: actions/setup-node@v4
        with: { node-version-file: '.nvmrc', cache: pnpm }
      - run: pnpm install --frozen-lockfile
      - run: COMMIT_LINT_FROM=origin/main pnpm ci:commits
```

This is a sketch, not the final file — the final lands with the scaffold and any iteration on it is not by itself an ADR-worthy change.

**Branch protection (Gitea-side configuration):** `Settings → Branches → Add rule` on `main`:
- Disable force push: yes;
- Disable direct push: yes (only PR merge);
- Required status checks: `check`, `scan`, `commits`, plus future `a11y`, `perf`;
- Require pull request reviews: 0 in v1, raise to 1 when a second contributor joins;
- Require linear history: yes;
- Delete head branches after merge: yes.

### Migration to GitLab — what changes, what doesn't

When the GitLab migration happens (6–18-month horizon), a new ADR will be written that **supersedes only the level-2 sections** of this ADR. The level-1 decisions stand unchanged. Concretely the migration touches:

- `.gitea/workflows/*.yml` → `.gitlab-ci.yml` (rewrite — the *gates* are the same, the *DSL* is different). Estimate: 1–2 days.
- Self-hosted `act_runner` → GitLab Runner. Estimate: 0.5–1 day.
- Gitea branch protection rules → GitLab merge request approval rules. Same concepts, different UI. Estimate: a few hours.
- Secrets re-creation in GitLab CI/CD variables. Same naming convention, copy values. Estimate: a few hours.

The `package.json` scripts (`ci:check`, `ci:scan`, `ci:commits`), the Nx workspace, the dependency manifest, the entire code surface, and the level-1 decisions are unchanged.

### Consequences

* Good, because the gates are written once and run twice (locally via hooks, in CI as defense). Drift is impossible without breaking both layers.
* Good, because thin YAML keeps CI reproducible locally — anyone can run `pnpm ci:check` to mirror what the runner does.
* Good, because Gitea Actions' GHA-compatible syntax doubles as a hedge: the same YAML can land on GitHub Actions if the org's plans change again.
* Good, because squash-merge produces a Conventional-Commits-only history on `main` — clean changelog generation, predictable release notes, smooth semver inference.
* Good, because branch protection is enforced at the platform level, not at convention level.
* Good, because the migration weight is bounded and transparent: ~3–5 days of dev/ops work, no code rewrite.
* Bad, because the level-2 sections will need to be rewritten at the GitLab migration. This is the explicit trade-off; it is accepted because the alternatives (going GitLab now without the existing tooling, or staying CI-less until GitLab) cost more.
* Bad, because trunk-based with required-reviewers=0 in v1 leaves the project lead as the sole gatekeeper. Mitigated by mandating green CI (which the lead cannot bypass without rewriting branch protection — a deliberate, audit-visible action).
* Bad, because `act_runner` is younger than GitLab Runner; expect occasional rough edges, especially around large action ecosystems. Mitigated by pinning third-party actions by SHA and cadence-rebuilding the runner image.
* Bad, because deferring signed commits to v2 means the v1 history won't carry attribution-grade signatures. Reasonable for a small team; revisit at GitLab migration.

### Confirmation

* `.gitea/workflows/ci.yml`, `release.yml`, `security-scheduled.yml` exist with the structure above. The `release.yml` may be a stub until the deploy ADR lands.
* `package.json` exposes `ci:check`, `ci:scan`, `ci:commits` scripts. Each is runnable locally and produces the same exit code as the CI job.
* Gitea branch protection on `main` has the rules above; configuration is documented in `docs/operations/branch-protection.md` (created with the scaffold).
* `Trivy`, `gitleaks`, and `commitlint` are in `devDependencies` (or available as actions pinned by SHA — both acceptable).
* At least three `act_runner` instances are registered to the org; their bootstrap and update procedure live in an operations doc.
* CI exits non-zero on any gate failure; no gate is `continue-on-error: true`.
* Runner images are pinned by SHA in the workflows. The `security-scheduled.yml` job rebuilds the runner image weekly and reports to the security audit feed.
* A future migration ADR (GitLab) explicitly references this ADR, supersedes only level 2, and inherits level 1.

## Pros and Cons of the Options

### Branch / merge strategy

#### Trunk-based + squash-merge (chosen)

* Good, because clean linear history on `main`, one squash commit per PR.
* Good, because Conventional Commits + squash-merge yields a directly machine-readable changelog.
* Good, because feature branches stay short-lived — pressure against long-lived branches becomes structural, not cultural.
* Bad, because contributors lose granular commit history on the merged branch (the squash collapses it). Mitigated: the PR retains the full history for review purposes.

#### Trunk-based + rebase-merge

* Good, because preserves individual commits without merge bubbles.
* Bad, because contributors must groom every commit to be CI-clean (each commit must compile and pass tests if we want a clean bisect history). High discipline cost; squash-merge gets most of the benefit at lower cost.

#### Trunk-based + merge commit

* Good, because preserves the full history, including the branch topology.
* Bad, because produces messy merge bubbles on `main`; conflicts with the "linear history" branch protection.

#### GitFlow

* Good, because release branches isolate stabilisation.
* Bad, because heavy for a continuously deployable monorepo; redundant with semver tags on a trunk-based main; introduces the "long-lived `develop` branch" anti-pattern.

### CI engine (level 2)

#### Gitea Actions (chosen)

* Good, because built-in to Gitea, no extra deployment.
* Good, because GitHub Actions syntax means transferable skills and a partial portability hedge.
* Good, because actively developed by the Gitea team.
* Bad, because younger ecosystem than GitLab CI or GitHub Actions proper — expect occasional rough edges.

#### Drone CI

* Good, because mature, lean, opinionated.
* Bad, because separate deployment and operational surface; YAML is Drone-specific (less portable than GHA-compatible Gitea Actions).

#### Concourse / Tekton / Buildkite

* Good, because powerful for complex pipelines.
* Bad, because over-engineered for the v1 scope, and orthogonal to the Gitea/GitLab decision axis.

### Required reviewer count

#### 0 in v1, raise later (chosen)

* Good, because doesn't block solo development.
* Good, because the green-CI requirement still prevents the project lead from merging broken code without effort.
* Bad, because relies on the project lead's discipline (and CI's correctness) for code quality.

#### 1 always

* Good, because rigour.
* Bad, because blocks if there's only one contributor — would force the project lead to merge their own PRs by overriding protection, which is the opposite of the intended behaviour.

### Signed commits

#### Optional in v1, revisited at GitLab migration (chosen)

* Good, because no setup overhead for contributors during a phase where the priority is shipping the structural ADRs and scaffolding.
* Bad, because v1 history carries no attribution-grade signatures. Acceptable: the host (Gitea) records the user identity on each commit.

#### Required in v1

* Good, because rigorous attribution from day one.
* Bad, because every contributor must set up GPG or SSH signing — high friction for early stages.

## More Information

* Gitea Actions: https://docs.gitea.com/usage/actions/overview
* `act_runner`: https://gitea.com/gitea/act_runner
* GitHub Actions reference (compatible with Gitea Actions): https://docs.github.com/actions
* Conventional Commits: https://www.conventionalcommits.org/
* commitlint: https://commitlint.js.org/
* Trivy: https://github.com/aquasecurity/trivy
* gitleaks: https://github.com/gitleaks/gitleaks
* `nrwl/nx-set-shas`: https://github.com/nrwl/nx-set-shas
* Related ADRs: [ADR-0002](0002-adopt-nx-monorepo-apps-preset.md) (Nx workspace + `affected`), [ADR-0007](0007-pre-commit-hooks-and-conventional-commits.md) (local hooks + commitlint config), and the future ADRs for security baseline (Trivy / gitleaks / Renovate config), accessibility baseline (`a11y` gate), performance budgets (`perf` gate), on-prem infrastructure stack (deploy pipeline, runners hosting), and GitLab migration (level-2 supersession).