From 364d509949f41f671465853d33e931321237b777 Mon Sep 17 00:00:00 2001
From: Robbie Blaine <4052340+rblaine95@users.noreply.github.com>
Date: Tue, 22 Oct 2024 16:41:10 +0000
Subject: [PATCH] Improved Docker build action

* Split each architecture with a matrix build so each arch builds on
  it's own runner
* Cache all architectures in GHA
* Combine and push in final step
---
 .github/workflows/docker.yml | 45 ++++++++++++++++++++++++++++++++----
 1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 23ca067..2a7b04d 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -9,14 +9,44 @@ env:
 jobs:
   build:
     name: Build
+    runs-on: ${{ matrix.runs-on }}
+    strategy:
+      matrix:
+        arch: [amd64, arm64, armv7]
+        include:
+          - arch: amd64
+            runs-on: ubuntu-latest
+            platform: linux/amd64
+          - arch: arm64
+            runs-on: ubuntu-latest
+            platform: linux/arm64
+            # One day, when ARM based Github Hosted Runners are GA...
+            # https://github.com/github/roadmap/issues/970
+            # runs-on: ubuntu-latest-arm64
+          - arch: armv7
+            runs-on: ubuntu-latest
+            platform: linux/arm/v7
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-qemu-action@v3
+        if: ${{ matrix.arch != 'amd64' }}
+      - uses: docker/setup-buildx-action@v3
+      - uses: docker/build-push-action@v6
+        with:
+          platforms: ${{ matrix.platform }}
+          push: false
+          cache-from: |
+            type=gha,scope=docker-build-${{ matrix.arch }}
+          cache-to: |
+            type=gha,mode=max,scope=docker-build-${{ matrix.arch }}
+          context: .
+  combine:
+    needs: [build]
     runs-on: ubuntu-latest
     permissions:
       contents: read
       packages: write
     steps:
-      - uses: actions/checkout@v4
-      - uses: docker/setup-qemu-action@v3
-      - uses: docker/setup-buildx-action@v3
       - uses: docker/login-action@v3
         with:
           registry: ghcr.io
@@ -42,5 +72,10 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-          cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-from: |
+            type=gha,scope=docker-package
+            type=gha,scope=docker-build-amd64
+            type=gha,scope=docker-build-arm64
+            type=gha,scope=docker-build-armv7
+          cache-to: |
+            type=gha,mode=max,scope=docker-package