From f3f2c6f8ea90594d0b2908a3622ecde5b4f7bd5a Mon Sep 17 00:00:00 2001
From: Mechiel Lukkien <mechiel@ueber.net>
Date: Mon, 27 Feb 2023 13:46:29 +0100
Subject: [PATCH] fix cross-compiled docker images

binaries for linux/amd64 were build for each target platform. apparently the
--platform in the first-stage overrides the $TARGET* variables of the build.
docker behaviour always manages to surprise me...
---
 Dockerfile.release |  8 ++++++--
 docker-release.sh  | 19 ++++++++++++-------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/Dockerfile.release b/Dockerfile.release
index 35b8f7b..9e698ae 100644
--- a/Dockerfile.release
+++ b/Dockerfile.release
@@ -1,8 +1,12 @@
 FROM --platform=linux/amd64 docker.io/golang:1-alpine AS build
+# note: cannot use $TARGETOS or $TARGETARCH because apparently the --platform in
+# the FROM above overrides the actual target os/arch from the command-line.
+ARG goos
+ARG goarch
 WORKDIR /
 ARG moxversion
-RUN CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=$TARGETARCH go install -mod mod -trimpath github.com/mjl-/mox@$moxversion
-RUN test -f /go/bin/mox && cp /go/bin/mox /bin/mox || cp /go/bin/${TARGETOS}_${TARGETARCH}/mox /bin/mox
+RUN CGO_ENABLED=0 GOOS=$goos GOARCH=$goarch go install -mod mod -trimpath github.com/mjl-/mox@$moxversion
+RUN test -f /go/bin/mox && cp /go/bin/mox /bin/mox || cp /go/bin/${goos}_${goarch}/mox /bin/mox
 
 # Using latest may break at some point, but will hopefully be convenient most of the time.
 FROM --platform=$TARGETPLATFORM docker.io/alpine:latest
diff --git a/docker-release.sh b/docker-release.sh
index 1f0e42c..8476d5a 100755
--- a/docker-release.sh
+++ b/docker-release.sh
@@ -32,18 +32,23 @@ alpineversion=alpine$(podman run alpine:latest cat /etc/alpine-release)
 # We assume the alpines for all platforms have the same version...
 echo Building with $goversion and $alpineversion
 
+# We build the images individually so we can pass goos and goarch ourselves,
+# needed because the platform in "FROM --platform <image>" in the first stage
+# seems to override the TARGET* variables.
 test -d empty || mkdir empty
-podman build --platform $platforms -f Dockerfile.release -v $HOME/go/pkg/sumdb:/go/pkg/sumbd:ro --build-arg moxversion=$moxversion --manifest docker.io/moxmail/mox:$moxversion-$goversion-$alpineversion empty
+(podman manifest rm moxmail/mox:$moxversion-$goversion-$alpineversion || exit 0)
+for platform in $(echo $platforms | sed 's/,/ /g'); do
+	goos=$(echo $platform | sed 's,/.*$,,')
+	goarch=$(echo $platform | sed 's,^.*/,,')
+	podman build --platform $platform -f Dockerfile.release -v $HOME/go/pkg/sumdb:/go/pkg/sumbd:ro --build-arg goos=$goos --build-arg goarch=$goarch --build-arg moxversion=$moxversion --manifest moxmail/mox:$moxversion-$goversion-$alpineversion empty
+done
 
 cat <<EOF
 
 # Suggested commands to push images:
 
-podman manifest push --all docker.io/moxmail/mox:$moxversion-$goversion-$alpineversion
+podman manifest push --all moxmail/mox:$moxversion-$goversion-$alpineversion docker.io/moxmail/mox:$moxversion-$goversion-$alpineversion
 
-podman tag docker.io/moxmail/mox:$moxversion-$goversion-$alpineversion docker.io/moxmail/mox:$moxversion
-podman manifest push --all docker.io/moxmail/mox:$moxversion
-
-podman tag docker.io/moxmail/mox:$moxversion docker.io/moxmail/mox:latest
-podman manifest push --all docker.io/moxmail/mox:latest
+podman manifest push --all moxmail/mox:$moxversion-$goversion-$alpineversion docker.io/moxmail/mox:$moxversion
+podman manifest push --all moxmail/mox:$moxversion-$goversion-$alpineversion docker.io/moxmail/mox:latest
 EOF