Merge pull request #7806 from planetscale/planetscale/gedgar-xbuild

Makefile: add cross-build target for cross-compiling client binaries

Makefile

@@ -75,6 +75,22 @@ endif
 	# build vtorc with CGO, because it depends on sqlite
 	CGO_ENABLED=1 go install $(EXTRA_BUILD_FLAGS) $(VT_GO_PARALLEL) -ldflags "$(shell tools/build_version_flags.sh)" ./go/cmd/vtorc/...
 
+# xbuild can be used to cross-compile Vitess client binaries
+# Outside of select client binaries (namely vtctlclient & vtexplain), cross-compiled Vitess Binaries are not recommended for production deployments
+# Usage: GOOS=darwin GOARCH=amd64 make xbuild
+cross-build:
+ifndef NOBANNER
+	echo $$(date): Building source tree
+endif
+	bash ./build.env
+	# In order to cross-compile, go install requires GOBIN to be unset
+	export GOBIN=""
+	# For the specified GOOS + GOARCH, build all the binaries by default with CGO disabled
+	CGO_ENABLED=0 GOOS=${GOOS} GOARCH=${GOARCH} go install $(EXTRA_BUILD_FLAGS) $(VT_GO_PARALLEL) -ldflags "$(shell tools/build_version_flags.sh)" ./go/...
+	# unset GOOS and embed local resources in the vttablet executable
+	(cd go/cmd/vttablet && unset GOOS && go run github.com/GeertJohan/go.rice/rice --verbose append --exec=$${HOME}/go/bin/${GOOS}_${GOARCH}/vttablet)
+	# Cross-compiling w/ cgo isn't trivial and we don't need vtorc, so we can skip building it 
+
 debug:
 ifndef NOBANNER
 	echo $$(date): Building source tree