Add action to run on pull requests

Signed-off-by: Marcelo E. Magallon <marcelo.magallon@grafana.com>

.github/workflows/pr.yml

@@ -0,0 +1,76 @@
+name: "Validate pull request"
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - Makefile
+      - Dockerfile
+      - lib/**
+      - scripts/**
+      - .github/workflows/**
+
+  workflow_dispatch:
+
+env:
+  TEST_TAG: grafana/${{ github.repository }}:test
+
+jobs:
+  validate:
+    name: Validate pull request
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-tags: true
+
+      - name: Unshallow
+        run: git fetch --prune --tags --unshallow
+
+      - name: Describe the current state
+        run: git describe --tags --always
+
+      - name: Docker meta
+        id: docker_meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ghcr.io/${{ github.repository }}
+          tags: |
+            type=raw,value=sha-${{ github.sha }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Cache Docker layers
+        uses: actions/cache@v3
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-
+
+      - name: Login to GitHub Package Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - # This will only build the container image, not publish it
+        name: Build container image and export to Docker
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: false
+          load: true
+          tags: ${{ steps.docker_meta.outputs.tags }}
+          labels: ${{ steps.docker_meta.outputs.labels }}
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache-new,mode=max
+
+      - name: Test container image
+        run: |
+          docker run --rm ghcr.io/${{ github.repository }}:sha-${{ github.sha }} image-test

.github/workflows/publish.yml

@@ -16,7 +16,7 @@ on:
 jobs:
   publish:
     name: Publish container images
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:

Dockerfile

@@ -1,6 +1,6 @@
 FROM registry.hub.docker.com/library/golang:1.21.3 as go-build
 
-    COPY go.env /usr/local/go
+    COPY lib/go.env /usr/local/go
 
     RUN env GOBIN=/build go install github.com/google/go-jsonnet/cmd/jsonnet@v0.20.0
     RUN env GOBIN=/build go install github.com/google/go-jsonnet/cmd/jsonnetfmt@v0.20.0
@@ -93,4 +93,4 @@ FROM registry.hub.docker.com/library/debian:stable-slim
     # what comes from the image vs stuff coming from the base image.
     COPY --from=go-build /build/* /usr/local/bin/
 
-    COPY image-test /usr/local/bin
+    COPY lib/image-test /usr/local/bin

README.md

@@ -13,7 +13,7 @@ First you need to confirm that the image is building and that the changes are pr
 
 Once you confirmed the build passes and the changes are as expected do the following:
 
-1. create a commit with `Makefile`, `Dockerfile` and `image-test` changes.
+1. create a commit with `Makefile`, `Dockerfile` and `lib/image-test` changes.
 2. push the changes and create a new pull request.
 
 After the PR gets reviewed you need to check all the different places where `grafana-build-tools` is used and update accordingly. Here [`git grep`](http://git-scm.com/docs/git-grep) is your friend: