Merge branch 'makefile'

Add the ability to customize:

- GOOS (defaults to 'linux' for tini)
- GOARCH (defaults to 'amd64' for tini)
- DOCKEROPTS (for container build customization)

Makefile

@@ -24,14 +24,16 @@
 NAME ?= bss
 VERSION ?= $(shell cat .version)
 BINARIES = boot-script-service bss-init
+GOOS := $(if $(GOOS),$(GOOS),linux)
+GOARCH := $(if $(GOARCH),$(GOARCH),amd64)
 
 
 all : image unittest ct snyk ct_image
 
 binaries: $(BINARIES)
 
 %: cmd/%/*.go
-	GOOS=linux GOARCH=amd64 go build -v -tags musl $(LDFLAGS) -o $@ ./$(dir $<)
+	GOOS=$(GOOS) GOARCH=$(GOARCH) go build -v -tags musl $(LDFLAGS) -o $@ ./$(dir $<)
 
 clean:
 	rm -f $(BINARIES)
@@ -52,4 +54,4 @@ ct_image:
 	docker build --no-cache -f test/ct/Dockerfile test/ct/ --tag hms-bss-hmth-test:${VERSION}
 
 docker: $(BINARIES)
-	docker build --tag openchami/bss:v$(VERSION)-dirty .
+	docker build --tag openchami/bss:v$(VERSION)-dirty $(DOCKEROPTS) .