util-docker: Proof-of-concept using Docker buildx

Introduced in https://github.com/gem5/gem5/pull/236 the
"docker-build.yaml" file will allow us to build and push docker images
to the GitHub Container Registry. This allows for both automation of
docker image building and allows us to utilize Github's zero-cost
pulling policy for downloads to GitHub Actions runners.

In this PR https://github.com/gem5/gem5/pull/236 has been altered to
use Docker `buildx` which allows for multi-platform Docker Image builds.
A multi-platform Docker image pull automatically pull the correct image
for your platform from a single URL. In this prototype the images are
build to both `linux/arm64` and `linux/amd64` have been set.

Docker `buildx` has it's own file format for specifying image builds
called `bake`. "util/dockerfiles/docker-bake.hcl" has been added with
the goal of replacing "util/dockerfiles/docker-compose.yaml".

In this proof-of-concept doesn't build all our docker images, just
enough to ensure it works inside our actions as intended.

Change-Id: Id0debed216c91ec514aa4fce3bc2ff4fc2ea669b

.github/workflows/docker-build.yaml

@@ -1,42 +1,39 @@
-#
 name: Docker images build and push
 
 on:
-  push:
-    branches:
-      - develop
-    paths:
-      - 'util/docker/ubuntu-20.04_all-depenencies'
   workflow_dispatch:
-
-env:
-  IMAGE_NAME: ubuntu-20.04_all-depenencies
-#
 jobs:
   # This builds and pushes the docker image.
-  push:
+  build-and-push:
     runs-on: [self-hosted, linux, x64, run]
     permissions:
       packages: write
       contents: read
+    container: gcr.io/gem5-test/ubuntu-22.04_all-dependencies:latest
 
     steps:
       - uses: actions/checkout@v3
+        name: Checkout the develop branch
+        with:
+            # Scheduled workflows run on the default branch by default. We
+            # therefore need to explicitly checkout the develop branch.
+            ref: develop
 
-      - name: Build image
-        run: |
-          cd util/docker/ubuntu-20.04_all-depenencies
-          docker build . --file Dockerfile --tag $IMAGE_NAME --label "runnumber=${GITHUB_RUN_ID}"
+      - uses: docker/setup-qemu-action@v2
+        name: Setup QEMU
 
-      - name: Log in to registry
-        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u $ --password-stdin
+      - uses: docker/setup-buildx-action@v2
+        name: Set up Docker Buildx
 
-      - name: Push image
-        run: |
-          IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
+      - uses: docker/login-action@v2
+        name: Login to the GitHub Container Registry
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
 
-          # This changes all uppercase characters to lowercase.
-          IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
-
-          docker tag $IMAGE_NAME $IMAGE_ID:latest
-          docker push $IMAGE_ID::latest
+      - name: Build and push with bake
+        uses: docker/bake-action@v3
+        with:
+          files: util/dockerfiles/docker-bake.hcl
+          push: true

util/dockerfiles/docker-bake.hcl

@@ -0,0 +1,83 @@
+# Copyright (c) 2023 The Regents of the University of California
+# All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# docker buildx bake --push
+# https://docs.docker.com/build/bake/reference
+
+variable "IMAGE_URI" {
+  default = "ghcr.io/gem5" # The gem5 GitHub container registry.
+}
+
+variable "TAG" {
+  default = "latest"
+}
+
+# A group of targets to be built. Note: groups can contain other groups.
+# Any target or group can be build individually. I.e.:
+# `docker buildx bake --push ubuntu-20-04_all-dependencies` or
+# `docker buildx bake --push ubuntu-releases`.
+group "default" {
+  targets=["clang-compilers", "ubuntu-releases"]
+}
+
+group "ubuntu-releases" {
+    targets=["ubuntu-22-04_all-dependencies", "ubuntu-20-04_all-dependencies"]
+}
+
+# Common attributes across all targets. Note: these can be overwritten.
+target "common" {
+  # Here we are enabling multi-platform builds. We are compiling to both ARM
+  # amd X86.
+  platforms = ["linux/amd64", "linux/arm64"]
+}
+
+target "clang-compilers" {
+    name="clang-compilers-${replace(ver, ".", "-")}"
+    inherits = ["common"]
+    context = "ubuntu-20.04_clang-version"
+    dockerfile = "Dockerfile"
+    matrix = {
+        ver = ["6.0","7","8","9","10","11"]
+    }
+    args = {
+        version=ver
+    }
+    tags = ["${IMAGE_URI}/clang-version-${ver}:${TAG}"]
+}
+
+target "ubuntu-22-04_all-dependencies" {
+  inherits = ["common"]
+  dockerfile = "Dockerfile"
+  context = "ubuntu-22.04_all-dependencies"
+  tags = ["${IMAGE_URI}/ubuntu-22.04_all-dependencies:${TAG}"]
+}
+
+target "ubuntu-20-04_all-dependencies" {
+  inherits = ["common"]
+  dockerfile = "Dockerfile"
+  context = "ubuntu-20.04_all-dependencies"
+  tags = ["${IMAGE_URI}/ubuntu-20.04_all-dependencies:${TAG}"]
+}

util/dockerfiles/ubuntu-20.04_all-dependencies/Dockerfile

@@ -24,7 +24,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-FROM ubuntu:20.04
+FROM --platform=${BUILDPLATFORM} ubuntu:20.04
 
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt -y update && apt -y upgrade && \

util/dockerfiles/ubuntu-20.04_clang-version/Dockerfile

@@ -23,7 +23,7 @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-FROM ubuntu:20.04
+FROM --platform=${BUILDPLATFORM} ubuntu:20.04
 
 # Valid version values:
 # 6.0

util/dockerfiles/ubuntu-22.04_all-dependencies/Dockerfile

@@ -24,7 +24,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-FROM ubuntu:22.04
+FROM --platform=${BUILDPLATFORM} ubuntu:22.04
 
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt -y update && apt -y upgrade && \