Added make target for prebuilding binary for mutliple targets

.gitignore

@@ -1 +1,3 @@
 /bin
+/release
+/build

Makefile

@@ -1,20 +1,35 @@
 SOURCEDIR=.
 SOURCES := $(shell find $(SOURCEDIR) -name '*.go')
 
-BINARY=bin/terraform-provider-zabbix
+BUILD_PATH=build
+BINARY=terraform-provider-zabbix
+BIN=bin
+TARGETS=darwin linux windows
+VERSION=0.0.2
+RELEASE_DIR=release
+RELEASE=terraform-provider-zabbix_$(VERSION).tar.gz
 
-VERSION=1.0.0
-BUILD_TIME=`date +%FT%T%z`
+build=GOOS=$(1) GOARCH=$(2) go build -o ${BUILD_PATH}/$(BINARY)/$(1)_$(2)/${BINARY}`if [ "$(1)" = "windows" ]; then echo ".exe"; fi` main.go
 
 .DEFAULT_GOAL: $(BINARY)
 
-$(BINARY): $(SOURCES)
-	go build ${LDFLAGS} -o ${BINARY} main.go
+$(BIN)/$(BINARY): $(SOURCES)
+	go build -o $(BIN)/${BINARY} main.go
+
+$(TARGETS): $(SOURCES)
+	$(call build,$@,amd64,$(ext))
+	$(call build,$@,386,$(ext))
+
+release: $(TARGETS)
+	mkdir -p $(RELEASE_DIR)
+	tar -czvf $(RELEASE_DIR)/$(RELEASE) -C $(BUILD_PATH) $(BINARY)
 
 install:
 	go install ./...
 
 clean:
-	if [ -f ${BINARY} ] ; then rm ${BINARY} ; fi
+	@if [ -f ${BINARY} ] ; then rm ${BINARY} ; fi
+	@if [ -d ${BUILD_PATH} ]; then rm -r ${BUILD_PATH} ; fi
+	@if [ -d ${RELEASE_DIR} ]; then rm -r $(RELEASE_DIR) ; fi
 
-.PHONY: clean install
+.PHONY: clean install build release $(TARGETS)