add makefile

Makefile

@@ -0,0 +1,45 @@
+export CGO_ENABLED = 0
+
+export GO111MODULE := on
+
+project_dir = $(shell pwd)
+builds_dir = $(shell echo $${builds_dir:-$(project_dir)/builds})
+
+UNAME_S := $(shell uname -s)
+UNAME_P := $(shell uname -p)
+
+GOOS = linux
+ifeq ($(UNAME_S),Darwin)
+  GOOS = darwin
+endif
+
+GOARCH = amd64
+ifneq ($(UNAME_P),x86_64)
+  GOARCH = 386
+endif
+
+.PHONY: _build
+_build:
+	@echo "=> building dockma via go build"
+	@echo ""
+	@builds_dir=${builds_dir} GOOS=${GOOS} GOARCH=${GOARCH} go build -o "$(builds_dir)/dockma_$(GOOS)_$(GOARCH)" cmd/dockma.go
+	@echo "built $(builds_dir)/doctl_$(GOOS)_$(GOARCH)"
+
+.PHONY: native
+native: _build
+	@echo "==> build local version"
+	@echo ""
+	@mv $(builds_dir)/doctl_$(GOOS)_$(GOARCH) $(builds_dir)/doctl
+	@echo "installed as $(builds_dir)/doctl"
+
+.PHONY: clean
+clean:
+	@echo "==> remove builds"
+	@echo ""
+	@rm -rf builds
+
+.PHONY: example
+example:
+	@echo "==> test"
+	@echo ""
+	@echo "built $(builds_dir)/doctl_$(GOOS)_$(GOARCH)"