From 4ba7d5017419cfc592e4915a81f2a4e2e7cd3fb1 Mon Sep 17 00:00:00 2001
From: Nalin Dahyabhai <nalin@redhat.com>
Date: Thu, 24 Sep 2020 11:13:06 -0400
Subject: [PATCH] Makefile: add a local-cross target

Add a make target that cross-compiles for a handful of the possible
targets that `go tool dist list` can tell us about.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
---
 .travis.yml | 2 +-
 Makefile    | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index bb349078..d8392a8f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,4 +24,4 @@ install:
 
 script:
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]];   then hack/travis_osx.sh ; fi
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make vendor && ./hack/tree_status.sh && make check ; fi
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then make vendor && ./hack/tree_status.sh && make local-cross && make check ; fi
diff --git a/Makefile b/Makefile
index 0460b995..8e4028ae 100644
--- a/Makefile
+++ b/Makefile
@@ -126,6 +126,9 @@ static:
 .PHONY: bin/skopeo
 bin/skopeo:
 	$(GPGME_ENV) $(GO) build $(MOD_VENDOR) ${GO_DYN_FLAGS} ${LDFLAGS} -gcflags "$(GOGCFLAGS)" -tags "$(BUILDTAGS)" -o $@ ./cmd/skopeo
+bin/skopeo.%:
+	GOOS=$(word 2,$(subst ., ,$@)) GOARCH=$(word 3,$(subst ., ,$@)) $(GO) build $(MOD_VENDOR) ${LDFLAGS} -tags "containers_image_openpgp $(BUILDTAGS)" -o $@ ./cmd/skopeo
+local-cross: bin/skopeo.darwin.amd64 bin/skopeo.linux.arm bin/skopeo.linux.arm64 bin/skopeo.windows.386.exe bin/skopeo.windows.amd64.exe
 
 build-container:
 	${CONTAINER_RUNTIME} build ${BUILD_ARGS} -t "$(IMAGE)" .