build: retire legacy ci in favor of container build

.github/workflows/docker.yml

@@ -3,6 +3,7 @@ name: Build and Push Container
 on:
   push:
     branches: [main]
+  pull_request:
   workflow_dispatch:
     inputs:
       tag:
@@ -26,7 +27,7 @@ jobs:
       packages: write
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Set tag
         id: tag
@@ -44,9 +45,14 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Build and push
         uses: docker/build-push-action@v6
         with:
           context: .
-          push: true
+          push: ${{ github.event_name == 'push' || github.event_name == 'workflow_dispatch' }}
           tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.tag.outputs.tag }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

Dockerfile

@@ -1,38 +1,25 @@
 # syntax=docker/dockerfile:1
-# Based on https://depot.dev/docs/container-builds/optimal-dockerfiles/rust-dockerfile
-
-FROM rust:1 AS build
 
+FROM rust:1-trixie AS chef
 RUN cargo install cargo-chef --locked
-
 WORKDIR /app
 
-COPY Cargo.toml Cargo.lock ./
-COPY src ./src
-
-RUN cargo chef prepare --recipe-path recipe.json
-
-RUN --mount=type=cache,target=/usr/local/cargo/registry,sharing=locked \
-    --mount=type=cache,target=/usr/local/cargo/git,sharing=locked \
-    cargo chef cook --release --recipe-path recipe.json
-
+FROM chef AS planner
 COPY . .
+RUN cargo chef prepare
 
-RUN --mount=type=cache,target=/usr/local/cargo/registry,sharing=locked \
-    --mount=type=cache,target=/usr/local/cargo/git,sharing=locked \
-    cargo build --release --bin lila-push
+FROM chef AS builder
+COPY --from=planner /app/recipe.json recipe.json
+RUN cargo chef cook --release
+COPY . .
+RUN cargo build --release
 
 FROM debian:trixie-slim AS runtime
-
 RUN apt-get update && \
     apt-get install -y --no-install-recommends ca-certificates && \
     rm -rf /var/lib/apt/lists/*
-
 RUN groupadd -g 1001 lichess && \
     useradd -u 1001 -g lichess -m -d /home/lichess -s /bin/bash lichess
-
-COPY --from=build --chown=lichess:lichess /app/target/release/lila-push /usr/local/bin/lila-push
-
+COPY --from=builder --chown=lichess:lichess /app/target/release/lila-push /usr/local/bin/lila-push
 USER lichess
-
 ENTRYPOINT ["/usr/local/bin/lila-push"]