ci: replace buildkite pipeline with github actions

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [master]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    name: Tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - run: make ci_test
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - run: make ci_build
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - run: make ci_lint

.github/workflows/mirror-ci-image.yml

@@ -0,0 +1,46 @@
+name: Mirror CI image
+
+# Anonymous pulls from public ECR hit a rate limit on GitHub runners.
+# This copies the gridx dev image to GHCR, where CI pulls it from.
+# Runs on every change to this file and on manual dispatch.
+on:
+  push:
+    paths:
+      - .github/workflows/mirror-ci-image.yml
+  workflow_dispatch:
+    inputs:
+      source_tag:
+        description: Tag of public.ecr.aws/gridx/base-images to mirror
+        default: modbus-dev-1.21.latest
+      target_tag:
+        description: Tag to publish under ghcr.io/grid-x/modbus-dev
+        default: go1.21
+
+jobs:
+  mirror:
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+    env:
+      SOURCE: public.ecr.aws/gridx/base-images:${{ inputs.source_tag || 'modbus-dev-1.21.latest' }}
+      TARGET: ghcr.io/grid-x/modbus-dev:${{ inputs.target_tag || 'go1.21' }}
+    steps:
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Pull source image
+        run: |
+          for attempt in 1 2 3 4 5 6; do
+            docker pull "$SOURCE" && exit 0
+            echo "pull failed, retry $attempt in 30s"
+            sleep 30
+          done
+          exit 1
+
+      - name: Push to GHCR
+        run: |
+          docker tag "$SOURCE" "$TARGET"
+          docker push "$TARGET"

Makefile

@@ -1,11 +1,9 @@
 GO_FILES := $(shell find . -type f -name "*.go")
 GO_BUILD := CGO_ENABLED=0 go build -ldflags "-w -s"
-GO_TOOLS := public.ecr.aws/gridx/base-images:modbus-dev-1.21.latest
+GO_TOOLS := ghcr.io/grid-x/modbus-dev:go1.21
 DOCKER_RUN := docker run --init --rm -v $$PWD:/go/src/github.com/grid-x/modbus -w /go/src/github.com/grid-x/modbus
 GO_RUN := ${DOCKER_RUN} ${GO_TOOLS} bash -c
 
-BRANCH := $(shell echo ${BUILDKITE_BRANCH} | sed 's/\//_/g')
-
 all: bin/
 
 .PHONY: test