Multi-arch rootless image (amd64 + arm64)

Dockerfile.rootless

@@ -1,5 +1,13 @@
+# Multi-arch build (linux/amd64 + linux/arm64) without an emulated toolchain.
+# The build stage always runs on the build host's own platform ($BUILDPLATFORM):
+# the frontend and the generated Go sources are platform-independent, and the
+# gitea binary is cross-compiled for $TARGETPLATFORM with tonistiigi/xx
+# (clang + a target musl sysroot; cgo is needed for sqlite). Only the small
+# runtime stage below runs as the target platform.
+FROM --platform=$BUILDPLATFORM docker.io/tonistiigi/xx:1.6.1 AS xx
+
 #Build stage
-FROM docker.io/library/golang:1.20-alpine3.18 AS build-env
+FROM --platform=$BUILDPLATFORM docker.io/library/golang:1.20-alpine3.18 AS build-env
 
 ARG GOPROXY
 ENV GOPROXY ${GOPROXY:-direct}
@@ -10,18 +18,28 @@ ENV TAGS "bindata timetzdata $TAGS"
 ARG CGO_EXTRA_CFLAGS
 
 #Build deps
-RUN apk --no-cache add build-base git nodejs npm
+RUN apk --no-cache add build-base git nodejs npm clang lld
+COPY --from=xx / /
 
 #Setup repo
 COPY . ${GOPATH}/src/code.gitea.io/gitea
 WORKDIR ${GOPATH}/src/code.gitea.io/gitea
 
-#Checkout version if set
+#Checkout version if set, then build everything that does not depend on the
+#target platform (frontend assets + go generate / bindata) natively, once.
 RUN if [ -n "${GITEA_VERSION}" ]; then git checkout "${GITEA_VERSION}"; fi \
- && make clean-all build
-
-# Begin env-to-ini build
-RUN go build contrib/environment-to-ini/environment-to-ini.go
+ && make clean-all frontend go-check generate-backend
+
+#Cross-compile the backend and env-to-ini for the target platform
+ARG TARGETPLATFORM
+RUN xx-apk add --no-cache gcc musl-dev
+# Version string baked into the binary. By default the Makefile takes it from
+# `git describe`; pass it when the build context has no usable .git directory
+# (a git worktree, for example), e.g. GITEA_BUILD_VERSION=1.20.3+10-gabcdef012
+ARG GITEA_BUILD_VERSION
+RUN CGO_ENABLED=1 make GO=xx-go ${GITEA_BUILD_VERSION:+GITEA_VERSION=$GITEA_BUILD_VERSION} gitea \
+ && CGO_ENABLED=1 xx-go build contrib/environment-to-ini/environment-to-ini.go \
+ && xx-verify gitea environment-to-ini
 
 FROM docker.io/library/alpine:3.18
 LABEL maintainer="maintainers@gitea.io"

Makefile

@@ -1007,9 +1007,18 @@ generate-manpage:
 	@gzip -9 man/man1/gitea.1 && echo man/man1/gitea.1.gz created
 	@#TODO A small script that formats config-cheat-sheet.en-us.md nicely for use as a config man page
 
+DOCKER_PLATFORMS ?= linux/amd64,linux/arm64
+
 .PHONY: docker
 docker:
-	docker build -t $(DOCKER_REF) -f Dockerfile.rootless .
+	docker build --build-arg GITEA_BUILD_VERSION=$(GITEA_VERSION) -t $(DOCKER_REF) -f Dockerfile.rootless .
+
+# amd64 + arm64 image, pushed straight to the registry (a multi-platform image
+# cannot be loaded into the local image store). Always use a new DOCKER_TAG:
+#   make docker-multiarch DOCKER_IMAGE=dcodetech/gitea DOCKER_TAG=v1.20-dcode.N
+.PHONY: docker-multiarch
+docker-multiarch:
+	docker buildx build --platform $(DOCKER_PLATFORMS) --build-arg GITEA_BUILD_VERSION=$(GITEA_VERSION) -t $(DOCKER_REF) -f Dockerfile.rootless --push .
 # support also build args docker build --build-arg GITEA_VERSION=v1.2.3 --build-arg TAGS="bindata sqlite sqlite_unlock_notify"  .
 
 # This endif closes the if at the top of the file