add goarm handling in makefile (#176)

Author: xoxys

Dockerfile.multiarch

@@ -37,5 +37,4 @@ RUN apk --update add --virtual .build-deps curl && \
     rm -rf /tmp/*
 
 COPY --from=build /src/dist/drone-docker-buildx /bin/drone-docker-buildx
-
 ENTRYPOINT ["/usr/local/bin/dockerd-entrypoint.sh", "drone-docker-buildx"]

Makefile

@@ -24,6 +24,9 @@ XGO_TARGETS ?= linux/amd64,linux/arm64
 
 TARGETOS ?= linux
 TARGETARCH ?= amd64
+ifneq ("$(TARGETVARIANT)","")
+GOARM ?= $(subst v,,$(TARGETVARIANT))
+endif
 TAGS ?= netgo
 
 ifndef VERSION
@@ -71,7 +74,7 @@ test:
 build: $(DIST)/$(EXECUTABLE)
 
 $(DIST)/$(EXECUTABLE): $(SOURCES)
-	GOOS=${TARGETOS} GOARCH=${TARGETARCH} $(GO) build -v -tags '$(TAGS)' -ldflags '-extldflags "-static" $(LDFLAGS)' -o $@ ./cmd/$(EXECUTABLE)
+	GOOS=${TARGETOS} GOARCH=${TARGETARCH} GOARM=$(GOARM) $(GO) build -v -tags '$(TAGS)' -ldflags '-extldflags "-static" $(LDFLAGS)' -o $@ ./cmd/$(EXECUTABLE)
 
 $(DIST_DIRS):
 	mkdir -p $(DIST_DIRS)