From 13872ace65931f411fe6116c9bccc4d2c7e5ef67 Mon Sep 17 00:00:00 2001
From: Matt McCormick <matt@fideus.io>
Date: Wed, 24 Sep 2025 11:24:33 -0400
Subject: [PATCH] ci: push multi-arch images with manifest-tool

Instead of buildah.

- Simplified workflow: manifest-tool provides a more straightforward command-line interface for creating manifest lists
- Better integration: manifest-tool is specifically designed for manifest list/OCI index creation and management
- Cross-platform compatibility: Works with both Docker v2.2 manifest lists and OCI v1 indexes
- Template-based approach: The --template and --platforms flags provide a cleaner way to specify multi-arch images
---
 .github/workflows/main.yml |  7 +++++++
 Makefile                   | 17 +++++++++--------
 README.md                  |  8 ++++++++
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 26907c6..ced1388 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1547,6 +1547,13 @@ jobs:
           username: ${{ secrets.DOCKER_USER }}
           password: ${{ secrets.DOCKER_PASS }}
 
+      - name: Install manifest-tool
+        if: github.ref == 'refs/heads/master'
+        run: |
+          wget https://github.com/estesp/manifest-tool/releases/latest/download/binaries-manifest-tool.tar.gz -O - | tar -xz
+          sudo cp manifest-tool-linux-amd64 /usr/local/bin/manifest-tool
+          sudo chmod +x /usr/local/bin/manifest-tool
+
       - name: deploy-multi-arch
         if: github.ref == 'refs/heads/master'
         run: |
diff --git a/Makefile b/Makefile
index 1d310f0..a269bad 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@
 # Common values: docker, podman, buildah
 DOCKER := $(or $(OCI_EXE), docker)
 BUILD_DOCKER := $(or $(BUILD_DOCKER), $(DOCKER))
-BUILDAH := $(or $(BUILDAH_EXE), buildah)
+MANIFEST_TOOL := $(or $(MANIFEST_TOOL_EXE), manifest-tool)
 RM = --rm
 
 # Name of the docker-equivalent executable for running test containers.
@@ -382,16 +382,17 @@ $(addsuffix .push,$(STANDARD_IMAGES) $(NON_STANDARD_IMAGES)): $$(basename $$@)
 
 .SECONDEXPANSION:
 $(addsuffix .manifest,$(MULTIARCH_IMAGES) web-wasi-threads web-wasm): $$(basename $$@)
-	if $(BUILDAH) manifest exists $(ORG)/$(basename $@); then \
-		$(BUILDAH) manifest rm $(ORG)/$(basename $@); fi
-	$(BUILDAH) manifest create $(ORG)/$(basename $@)
-	$(BUILDAH) manifest add $(ORG)/$(basename $@) docker://$(ORG)/$(basename $@):latest-amd64
-	$(BUILDAH) manifest add $(ORG)/$(basename $@) docker://$(ORG)/$(basename $@):latest-arm64
+	$(MANIFEST_TOOL) push from-args \
+		--platforms linux/amd64,linux/arm64 \
+		--template $(ORG)/$(basename $@):latest-ARCH \
+		--target $(ORG)/$(basename $@):latest
 
 .SECONDEXPANSION:
 $(addsuffix .push,$(MULTIARCH_IMAGES) web-wasi-threads web-wasm): $$(basename $$@).manifest
-	$(BUILDAH) manifest push --all --format v2s2 $(ORG)/$(basename $@) docker://$(ORG)/$(basename $@):latest
-	$(BUILDAH) manifest push --all --format v2s2 $(ORG)/$(basename $@) docker://$(ORG)/$(basename $@):$(TAG)
+	$(MANIFEST_TOOL) push from-args \
+		--platforms linux/amd64,linux/arm64 \
+		--template $(ORG)/$(basename $@):$(TAG)-ARCH \
+		--target $(ORG)/$(basename $@):$(TAG)
 
 #
 # testing prerequisites implicit rule
diff --git a/README.md b/README.md
index 6322579..ec520a0 100644
--- a/README.md
+++ b/README.md
@@ -620,6 +620,14 @@ Note that the architecture is now `aarch64` instead of `amd64`, so it runs nativ
 
 \-\--
 
+## Multi-architecture Image Creation
+
+For creating multi-architecture container images, this project uses [manifest-tool](https://github.com/estesp/manifest-tool) to create and manage manifest lists that combine platform-specific images into a single multi-platform reference. This allows container runtimes to automatically select the appropriate image based on the target architecture.
+
+The multi-architecture images are built on different architectures (amd64 and arm64) and then combined using manifest-tool's `push from-args` command, which creates manifest lists pointing to the individual platform-specific images.
+
+---
+
 Credits:
 
 - [sdt/docker-raspberry-pi-cross-compiler](https://github.com/sdt/docker-raspberry-pi-cross-compiler), who invented the base of the **dockcross** script.