Add Docker pipeline

.github/workflows/push-docker-image.yaml

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+name: Push Docker image
+
+on:
+  push:
+    tags: [ 'v*.*.*' ]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  main:
+    name: Build and push Docker image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4.1.7
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3.4.0
+
+      - name: Log into registry ${{ env.REGISTRY }}
+        uses: docker/login-action@v3.2.0
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5.5.1
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        id: build-and-push
+        uses: docker/build-push-action@v6.3.0
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

Dockerfile

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+# Shared layer with dependencies
+FROM alpine:3.21.3 AS shared
+
+RUN apk add --no-cache \
+    lua5.4 \
+    make \
+    openssl \
+    pcre2
+
+
+
+# Build dependencies
+FROM shared AS build-deps
+
+RUN apk add --no-cache \
+    alpine-sdk \
+    lua5.4-dev \
+    openssl-dev \
+    pcre2-dev
+
+
+
+# Build layer
+FROM build-deps AS build
+
+RUN git clone https://github.com/lefcha/imapfilter.git /dist
+WORKDIR /dist
+RUN make \
+    INCDIRS=-I/usr/include/lua5.4 \
+    LDFLAGS='-L/usr/lib/lua5.4' \
+    LIBLUA=-llua \
+    LUA_CFLAGS=-I/usr/include/lua5.4
+
+
+
+# Final layer with installed imapfilter
+FROM shared AS final
+
+COPY --from=build /dist /dist
+WORKDIR /dist
+RUN make install \
+    && rm -rf /dist
+
+RUN addgroup abc \
+    && adduser \
+        --home /home/imapfilter \
+        --shell /sbin/nologin \
+        --disabled-password \
+        --ingroup abc \
+        abc
+
+USER abc:abc
+
+ENTRYPOINT [ "/usr/local/bin/imapfilter" ]
+CMD ["-c", "/config.lua"]