Add Docker image build to CI pipeline

Multi-stage Dockerfile using hotio/base:alpinevpn with s6-overlay.
Docker job runs after backend, unit-tests, and frontend pass.
Builds linux/amd64 and linux/arm64 images, pushes to GHCR on
non-PR events. Supports manual dispatch with optional version tag.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,12 @@
+.git
+.github
+.vscode
+.devcontainer
+_output
+_temp
+_tests
+_artifacts
+node_modules
+Logo
+*.md
+!LICENSE

.github/workflows/build.yml

@@ -1,8 +1,8 @@
-name: Build & Test
+name: Build, Test & Docker
 
 on:
   push:
-    branches: [develop, master]
+    branches: [develop, master, feature/**]
     paths-ignore:
       - 'src/NzbDrone.Core/Localization/Core/**'
       - 'src/Prowlarr.Api.*/openapi.json'
@@ -11,12 +11,20 @@ on:
     paths-ignore:
       - 'src/NzbDrone.Core/Localization/Core/**'
       - 'src/Prowlarr.Api.*/openapi.json'
+  workflow_dispatch:
+    inputs:
+      version:
+        description: "Version tag (e.g. 2.3.3.1234)"
+        required: false
+        type: string
 
 env:
   DOTNET_VERSION: '8.0.x'
   DOTNET_NOLOGO: true
   DOTNET_CLI_TELEMETRY_OPTOUT: true
   NODE_VERSION: '20'
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
 
 jobs:
   backend:
@@ -138,3 +146,67 @@ jobs:
 
       - name: Build
         run: yarn run build --env production
+
+  docker:
+    name: Build & Push Docker Image
+    runs-on: ubuntu-latest
+    needs: [backend, unit-tests, frontend]
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GHCR
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Determine version
+        id: version
+        env:
+          INPUT_VERSION: ${{ inputs.version }}
+        run: |
+          if [ -n "$INPUT_VERSION" ]; then
+            echo "version=$INPUT_VERSION" >> "$GITHUB_OUTPUT"
+          else
+            echo "version=$(git describe --tags 2>/dev/null || echo "dev-${GITHUB_SHA::8}")" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=ref,event=branch
+            type=sha,prefix=
+            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/develop' }}
+            type=raw,value=${{ steps.version.outputs.version }},enable=${{ inputs.version != '' }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            VERSION=${{ steps.version.outputs.version }}
+            VERSION_BRANCH=${{ github.ref_name }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

Dockerfile

@@ -0,0 +1,74 @@
+# Stage 1: Build backend
+FROM mcr.microsoft.com/dotnet/sdk:8.0-alpine AS backend
+WORKDIR /repo
+
+ARG TARGETPLATFORM
+RUN case "${TARGETPLATFORM}" in \
+      "linux/arm64") echo "linux-musl-arm64" > /tmp/rid ;; \
+      "linux/arm/v7") echo "linux-musl-arm" > /tmp/rid ;; \
+      *) echo "linux-musl-x64" > /tmp/rid ;; \
+    esac
+
+# Copy solution and project files first for layer caching on restore
+COPY src/Prowlarr.sln src/Directory.Build.props src/Directory.Build.targets src/NuGet.config src/stylecop.json src/
+COPY src/Targets/ src/Targets/
+COPY src/Libraries/ src/Libraries/
+COPY src/NzbDrone/Prowlarr.csproj src/NzbDrone/
+COPY src/NzbDrone.Common/Prowlarr.Common.csproj src/NzbDrone.Common/
+COPY src/NzbDrone.Console/Prowlarr.Console.csproj src/NzbDrone.Console/
+COPY src/NzbDrone.Core/Prowlarr.Core.csproj src/NzbDrone.Core/
+COPY src/NzbDrone.Host/Prowlarr.Host.csproj src/NzbDrone.Host/
+COPY src/NzbDrone.Mono/Prowlarr.Mono.csproj src/NzbDrone.Mono/
+COPY src/NzbDrone.SignalR/Prowlarr.SignalR.csproj src/NzbDrone.SignalR/
+COPY src/NzbDrone.Update/Prowlarr.Update.csproj src/NzbDrone.Update/
+COPY src/NzbDrone.Windows/Prowlarr.Windows.csproj src/NzbDrone.Windows/
+COPY src/Prowlarr.Api.V1/Prowlarr.Api.V1.csproj src/Prowlarr.Api.V1/
+COPY src/Prowlarr.Http/Prowlarr.Http.csproj src/Prowlarr.Http/
+COPY src/ServiceHelpers/ServiceInstall/ServiceInstall.csproj src/ServiceHelpers/ServiceInstall/
+COPY src/ServiceHelpers/ServiceUninstall/ServiceUninstall.csproj src/ServiceHelpers/ServiceUninstall/
+
+RUN dotnet restore src/Prowlarr.sln -r "$(cat /tmp/rid)" -p:SelfContained=true
+
+# Copy remaining source and build
+COPY src/ src/
+COPY LICENSE LICENSE
+
+RUN dotnet publish src/NzbDrone/Prowlarr.csproj \
+      -c Release \
+      -r "$(cat /tmp/rid)" \
+      --self-contained \
+      --no-restore \
+      -o /build/bin && \
+    rm -rf /build/bin/Prowlarr.Update /build/bin/Prowlarr.Windows.* \
+           /build/bin/ServiceInstall.* /build/bin/ServiceUninstall.*
+
+# Stage 2: Build frontend
+FROM node:20-alpine AS frontend
+WORKDIR /repo
+
+COPY package.json yarn.lock .yarnrc ./
+RUN yarn install --frozen-lockfile --network-timeout 120000
+
+COPY frontend/ frontend/
+COPY tsconfig.json ./
+RUN yarn build --env production
+
+# Stage 3: Runtime on hotio base
+FROM ghcr.io/hotio/base:alpinevpn
+
+EXPOSE 9696
+ENV WEBUI_PORTS="9696/tcp"
+
+RUN apk add --no-cache libintl sqlite-libs icu-libs
+
+COPY --from=backend /build/bin ${APP_DIR}/bin
+COPY --from=frontend /repo/_output/UI ${APP_DIR}/bin/UI
+
+ARG VERSION
+ARG VERSION_BRANCH=develop
+RUN echo -e "PackageVersion=${VERSION:-local}\nPackageAuthor=[nitrobass24](https://github.com/nitrobass24)\nUpdateMethod=Docker\nBranch=${VERSION_BRANCH}" \
+      > "${APP_DIR}/package_info" && \
+    chmod -R u=rwX,go=rX "${APP_DIR}"
+
+COPY root/ /
+RUN find /etc/s6-overlay/s6-rc.d -name "run*" -execdir chmod +x {} +

root/etc/s6-overlay/s6-rc.d/init-setup-app/run

@@ -0,0 +1,17 @@
+#!/command/with-contenv bash
+# shellcheck shell=bash
+
+# shellcheck source=/dev/null
+source /etc/s6-overlay/scripts/bash-functions
+
+set -e
+
+umask "${UMASK}"
+
+echo "
+----------------------------------------------------------------------
+ENVIRONMENT APP
+----------------------------------------------------------------------
+WEBUI_PORTS=${WEBUI_PORTS}
+----------------------------------------------------------------------
+"

root/etc/s6-overlay/s6-rc.d/init-setup-app/type

@@ -0,0 +1 @@
+oneshot

root/etc/s6-overlay/s6-rc.d/init-setup-app/up

@@ -0,0 +1 @@
+/etc/s6-overlay/s6-rc.d/init-setup-app/run

root/etc/s6-overlay/s6-rc.d/service-prowlarr/run

@@ -0,0 +1,7 @@
+#!/command/with-contenv bash
+# shellcheck shell=bash
+
+umask "${UMASK}"
+
+cd "${APP_DIR}/bin" || exit 1
+exec s6-setuidgid hotio "${APP_DIR}/bin/Prowlarr" --nobrowser --data="${CONFIG_DIR}"

root/etc/s6-overlay/s6-rc.d/service-prowlarr/type

@@ -0,0 +1 @@
+longrun