Add docker

.github/workflows/docker.yml

@@ -0,0 +1,53 @@
+---
+name: docker
+
+on:
+  push:
+    branches:
+      - '*'
+    tags:
+      - v*
+  pull_request:
+    branches:
+      - '*'
+  workflow_dispatch: {}
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-qemu-action@v3
+        with:
+          # Spurious segfaults when compiling
+          # https://github.com/docker/setup-qemu-action/issues/188
+          image: tonistiigi/binfmt:qemu-v8.1.5
+      - uses: docker/setup-buildx-action@v3
+
+      - uses: docker/metadata-action@v5
+        id: meta
+        with:
+          flavor: |
+            latest=false
+          images: |
+            name=ghcr.io/${{ github.repository }},enable=${{ github.repository == 'lefcha/imapfilter' }} # publishing to ghcr.io/lefcha/imapfilter
+            name=ghcr.io/${{ github.actor }}/imapfilter,enable=true # publish to the (PR) author's packages
+          tags: |
+            type=raw,value=latest,enable=${{ startsWith(github.ref, 'refs/tags/v') }} # set latest tag for releases
+            type=semver,pattern={{raw}} # uses git tag as image tag
+            type=ref,event=branch
+            type=ref,event=pr
+            type=sha
+
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: docker/build-push-action@v6
+        with:
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          platforms: linux/amd64,linux/arm64,linux/arm/v7

Dockerfile

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+FROM alpine AS builder
+
+RUN apk --no-cache add make gcc lua lua-dev openssl openssl-dev libc-dev pcre pcre-dev pcre2-dev
+
+WORKDIR /build
+
+ADD . /build
+RUN make && make install
+
+FROM alpine
+
+COPY --from=builder /usr/local/bin/imapfilter /usr/local/bin/imapfilter
+COPY --from=builder /usr/local/share/imapfilter /usr/local/share/imapfilter
+
+RUN apk --no-cache add lua lua-dev openssl pcre git \
+    && adduser -D -u 1000 imapfilter
+
+USER imapfilter
+
+ENTRYPOINT ["/usr/local/bin/imapfilter"]