# Build the Gitea and Caddy images, push them, and roll them out.
#
# The rollout works by kicking podman-auto-update on the VM. That is why the
# quadlets track a floating :prod tag rather than a digest: AutoUpdate=registry
# compares the local digest against the registry's digest FOR A TAG, so a
# digest-pinned image would give it nothing to poll.
#
# The :$SHORT_SHA and version tags are the audit trail and the rollback targets.

substitutions:
  _REGION: us-east1
  _ZONE: us-east1-b
  _DOMAIN: gitea.jasonmross.dev
  _REPO: gitea
  _VM: gitea-vm

options:
  # A user-specified service account cannot write to the legacy default log
  # bucket. Without this the very first build fails on storage.objects.create.
  logging: CLOUD_LOGGING_ONLY
  machineType: E2_HIGHCPU_8

timeout: 2400s

steps:
  - id: read-versions
    name: bash
    script: |
      #!/usr/bin/env bash
      set -euo pipefail
      mkdir -p /workspace/vars
      tr -d '[:space:]' < image/gitea.version > /workspace/vars/gitea_version
      tr -d '[:space:]' < image/caddy.version > /workspace/vars/caddy_version
      tr -d '[:space:]' < image/coraza.version > /workspace/vars/coraza_version
      echo "gitea=$(cat /workspace/vars/gitea_version) caddy=$(cat /workspace/vars/caddy_version) coraza=$(cat /workspace/vars/coraza_version)"

  - id: build-gitea
    name: gcr.io/cloud-builders/docker
    # Both Dockerfiles are written for BuildKit (`# syntax=`, COPY --chmod). This
    # builder image defaults to the legacy builder, which rejects --chmod.
    env: [DOCKER_BUILDKIT=1]
    entrypoint: bash
    args:
      - -c
      - |
        set -euo pipefail
        V=$(cat /workspace/vars/gitea_version)
        IMG="${_REGION}-docker.pkg.dev/$PROJECT_ID/${_REPO}/gitea"
        docker build \
          --build-arg "GITEA_VERSION=$${V}" \
          --tag "$${IMG}:prod" \
          --tag "$${IMG}:$SHORT_SHA" \
          --tag "$${IMG}:$${V}" \
          image/gitea

  - id: build-caddy
    name: gcr.io/cloud-builders/docker
    env: [DOCKER_BUILDKIT=1]
    entrypoint: bash
    # xcaddy runs inside the Dockerfile's golang builder stage, so the plain
    # docker builder is all this step needs -- no Go toolchain out here.
    args:
      - -c
      - |
        set -euo pipefail
        V=$(cat /workspace/vars/caddy_version)
        C=$(cat /workspace/vars/coraza_version)
        IMG="${_REGION}-docker.pkg.dev/$PROJECT_ID/${_REPO}/caddy"
        # The Dockerfile asserts both the DNS and WAF modules are present, so a
        # dropped --with fails the build rather than shipping an unprotected
        # server. Caddy and coraza-caddy versions are coupled: coraza-caddy
        # pins a minimum Caddy, and a mismatch fails here at `go get`.
        docker build \
          --build-arg "CADDY_VERSION=$${V}" \
          --build-arg "CORAZA_VERSION=$${C}" \
          --tag "$${IMG}:prod" \
          --tag "$${IMG}:$SHORT_SHA" \
          --tag "$${IMG}:$${V}" \
          image/caddy

  - id: push
    name: gcr.io/cloud-builders/docker
    entrypoint: bash
    args:
      - -c
      - |
        set -euo pipefail
        BASE="${_REGION}-docker.pkg.dev/$PROJECT_ID/${_REPO}"
        docker push --all-tags "$${BASE}/gitea"
        docker push --all-tags "$${BASE}/caddy"
        # Record the digests actually published. Pulumi does not pin these, so
        # the build log is where you look to find a rollback target.
        docker image inspect "$${BASE}/gitea:prod" --format '{{index .RepoDigests 0}}'
        docker image inspect "$${BASE}/caddy:prod" --format '{{index .RepoDigests 0}}'

  - id: rollout
    name: gcr.io/google.com/cloudsdktool/cloud-sdk:slim
    entrypoint: bash
    env:
      # gcloud needs a writable HOME to generate the ephemeral SSH key it pushes
      # through OS Login. The default HOME in this image is not writable.
      - HOME=/workspace
    args:
      - -c
      - |
        set -euo pipefail
        gcloud compute ssh "${_VM}" \
          --zone="${_ZONE}" \
          --tunnel-through-iap \
          --quiet \
          --command 'sudo systemctl start podman-auto-update.service'

  - id: verify
    name: gcr.io/google.com/cloudsdktool/cloud-sdk:slim
    entrypoint: bash
    # A build that pushes a broken image and reports success is worse than a
    # failed build. Gate on the app actually answering.
    args:
      - -c
      - |
        set -euo pipefail
        for i in $(seq 1 30); do
          if curl -fsS --max-time 10 "https://${_DOMAIN}/api/healthz" >/dev/null; then
            echo "healthz passed after $${i} attempt(s)"
            exit 0
          fi
          echo "waiting for https://${_DOMAIN}/api/healthz ($${i}/30)"
          sleep 10
        done
        echo "healthz never passed -- check 'journalctl -u podman-auto-update' on the VM;" >&2
        echo "podman should have rolled back automatically if the new image failed to start." >&2
        exit 1