docs: enhance README and CI workflow documentation for Docker image building and publishing process, including registry setup and job conditions for main/master branches

.gitea/workflows/ci.yaml

@@ -111,3 +111,126 @@ jobs:
             echo "==> $conf"
             bird -c "$WS/$conf" -p
           done
+
+  # Сборка образов и push в Container Registry Gitea (только push в main/master; см. .gitea/README.md).
+  docker-images:
+    needs: [go]
+    if: github.event_name == 'push' && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/master')
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - image: evobgp-api
+            dockerfile: deploy/docker/gobinary/Dockerfile
+            bin: evobgp-api
+            birdc: "1"
+          - image: evobgp-all
+            dockerfile: deploy/docker/gobinary/Dockerfile
+            bin: evobgp-all
+            birdc: "1"
+          - image: evobgp-scheduler
+            dockerfile: deploy/docker/gobinary/Dockerfile
+            bin: evobgp-scheduler
+            birdc: "0"
+          - image: evobgp-ingest
+            dockerfile: deploy/docker/gobinary/Dockerfile
+            bin: evobgp-ingest
+            birdc: "0"
+          - image: evobgp-render
+            dockerfile: deploy/docker/gobinary/Dockerfile
+            bin: evobgp-render
+            birdc: "0"
+          - image: evobgp-deploy
+            dockerfile: deploy/docker/gobinary/Dockerfile
+            bin: evobgp-deploy
+            birdc: "0"
+          - image: evobgp-node
+            dockerfile: deploy/docker/gobinary/Dockerfile
+            bin: evobgp-node
+            birdc: "0"
+          - image: evobgp-web
+            dockerfile: deploy/docker/evobgp-web/Dockerfile
+          - image: evobgp-agent
+            dockerfile: deploy/docker/evobgp-agent/Dockerfile
+          - image: evobgp-bird2
+            dockerfile: deploy/docker/bird2/Dockerfile
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Prepare registry (REGISTRY in env + outputs)
+        id: meta
+        env:
+          HOST: ${{ secrets.GITEA_REGISTRY_HOST }}
+        run: |
+          set -euo pipefail
+          owner_lc="$(echo '${{ github.repository_owner }}' | tr '[:upper:]' '[:lower:]')"
+          echo "owner_lc=$owner_lc" >> "$GITHUB_OUTPUT"
+          short_sha="$(echo '${{ github.sha }}' | cut -c1-7)"
+          echo "short_sha=$short_sha" >> "$GITHUB_OUTPUT"
+          if [ -z "${HOST:-}" ]; then
+            echo "GITEA_REGISTRY_HOST not set — build without push."
+            echo "docker_push=false" >> "$GITHUB_OUTPUT"
+            echo "REGISTRY=" >> "$GITHUB_ENV"
+          else
+            h="$HOST"
+            h="${h#https://}"
+            h="${h#http://}"
+            h="${h%/}"
+            echo "docker_push=true" >> "$GITHUB_OUTPUT"
+            echo "REGISTRY=$h" >> "$GITHUB_ENV"
+          fi
+
+      - name: Log in to Gitea Registry
+        if: steps.meta.outputs.docker_push == 'true' && secrets.ACTIONS_PAT != ''
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.ACTIONS_PAT }}
+
+      - name: Build and push ${{ matrix.image }}
+        env:
+          OWNER_LC: ${{ steps.meta.outputs.owner_lc }}
+          SHORT_SHA: ${{ steps.meta.outputs.short_sha }}
+          DO_PUSH: ${{ steps.meta.outputs.docker_push }}
+          PAT_OK: ${{ secrets.ACTIONS_PAT != '' }}
+          DF: ${{ matrix.dockerfile }}
+          IMAGE: ${{ matrix.image }}
+          BIN: ${{ matrix.bin }}
+          BIRDC: ${{ matrix.birdc }}
+        run: |
+          set -euxo pipefail
+          WS="${{ github.workspace }}"
+          cd "$WS"
+
+          TAG_LOCAL="evobgp:${IMAGE}-${SHORT_SHA}"
+          BUILD_ARGS=()
+          if [ -n "${BIN:-}" ]; then
+            BUILD_ARGS+=(--build-arg "BIN=${BIN}")
+            BUILD_ARGS+=(--build-arg "INSTALL_BIRDC=${BIRDC:-0}")
+          fi
+
+          if [ "$DO_PUSH" = "true" ] && [ -n "${REGISTRY:-}" ] && [ "$PAT_OK" = "true" ]; then
+            IMG="${REGISTRY}/${OWNER_LC}/${IMAGE}"
+            docker buildx build \
+              --platform linux/amd64 \
+              --file "$DF" \
+              "${BUILD_ARGS[@]}" \
+              --tag "${IMG}:latest" \
+              --tag "${IMG}:${SHORT_SHA}" \
+              --tag "${IMG}:sha-${{ github.sha }}" \
+              --push \
+              "$WS"
+          else
+            docker buildx build \
+              --platform linux/amd64 \
+              --file "$DF" \
+              "${BUILD_ARGS[@]}" \
+              --tag "$TAG_LOCAL" \
+              --load \
+              "$WS"
+          fi