Pre-build docker images on GitHub Actions (#25)

This means we don't need to build at deployment time, and means releases
are more obviously packaged up.

It also slims down the docker image - instead of a whole ubuntu image
(~600MB) we drop down to alpine.

Author: illicitonion

.dockerignore

@@ -5,17 +5,26 @@ on:
       - "v[0-9]+\\.[0-9]+\\.[0-9]"
   workflow_dispatch:
 
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
 jobs:
-  validate_pr_metadata:
+  publish:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
     container:
       image: rust:1.88.0-alpine
     steps:
       - uses: actions/checkout@v4
-      - name: Install gcc
-        run: apk add gcc g++
-      - name: Build validator
-        run: cargo build --release --bin pr-metadata-validator
+      - name: Install deps
+        run: apk add docker gcc g++
+      - name: Build binaries
+        run: cargo build --release
       - name: Create release
         id: create_release
         uses: softprops/action-gh-release@v1
@@ -34,3 +43,28 @@ jobs:
           asset_name: pr-metadata-validator-musl-${{ github.ref_name }}
           asset_path: target/release/pr-metadata-validator
           asset_content_type: application/octet-stream
+      - name: Log in to the Container registry
+        uses: docker/login-action@65b78e6e13532edd9afa3aa52ac7964289d1a9c1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
+      - name: Build and push Docker image
+        id: push
+        uses: docker/build-push-action@f2a1d5e99d037542a71f64918e516c093c6f3fc4
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+      - name: Generate artifact attestation
+        uses: actions/attest-build-provenance@v3
+        with:
+          subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}
+          subject-digest: ${{ steps.push.outputs.digest }}
+          push-to-registry: true

.github/workflows/release.yml

@@ -1,22 +1,7 @@
-FROM ekidd/rust-musl-builder@sha256:c18dbd9fcf3a4c0c66b8aacea5cf977ee38193efd7e98a55ee7bf9cd9954b221 AS build
+# alpine:3.22.2
+FROM alpine@sha256:4b7ce07002c69e8f3d704a9c5d6fd3053be500b7f1c69fc0d80990c2ad8dd412
 
-RUN sudo chown -R rust:rust /opt/rust/rustup
-
-RUN rustup install 1.88.0
-
-RUN rustup +1.88.0 target add x86_64-unknown-linux-musl
-
-RUN mkdir /tmp/src && chown rust:rust /tmp/src
-
-COPY . /tmp/src
-
-RUN cargo +1.88.0 build --release --manifest-path=/tmp/src/Cargo.toml
-
-FROM ubuntu:latest
-
-RUN apt-get update && apt-get install -y curl wget
-
-COPY --from=build /tmp/src/target/x86_64-unknown-linux-musl/release/trainee-tracker /trainee-tracker
+COPY target/release/trainee-tracker /trainee-tracker
 
 COPY config.prod.json /config.prod.json