refactor: change the code's whole structure

Makefile

@@ -0,0 +1,58 @@
+BINNAME = go-monitoring
+BINDIR = $(CURDIR)/bin
+TARGETS = linux/amd64 linux/386 linux/arm linux/arm64
+
+SRC := $(shell find . -type f -name '*.go' -print) go.mod go.sum
+GOHOSTOS = $(shell go env GOHOSTOS)
+GOHOSTARCH ?= $(shell go env GOHOSTARCH)
+
+GIT_TAG    = $(shell git describe --tags --abbrev=0 --exact-match 2>/dev/null)
+GIT_COMMIT = $(shell git rev-parse --short HEAD 2>/dev/null)
+GIT_STATUS = $(shell test -n "`git status --porcelain`" && echo "dirty" || echo "clean")
+
+ifneq ($(VERSION),)
+	BINARY_VERSION = $(VERSION)
+endif
+BINARY_VERSION ?= $(GIT_TAG)
+
+LDFLAGS += -w -s
+ifneq ($(BINARY_VERSION),)
+	LDFLAGS += -X nocternity.net/go-monitoring/pkg/version.version=${BINARY_VERSION}
+endif
+LDFLAGS += -X nocternity.net/go-monitoring/pkg/version.commit=${GIT_COMMIT}
+LDFLAGS += -X nocternity.net/go-monitoring/pkg/version.status=${GIT_STATUS}
+
+
+.PHONY: all
+all: build
+
+.PHONY: build
+build: GOOS=$(GOHOSTOS)
+build: GOARCH=$(GOHOSTARCH)
+build: build-target symlink
+
+.PHONY: symlink
+symlink:
+	@ln -sf $(BINDIR)/$(GOOS)/$(GOARCH)/$(BINNAME) $(BINDIR)/$(BINNAME)
+
+.PHONY: build-target
+build-target: LDFLAGS += -X nocternity.net/go-monitoring/pkg/version.target=${GOOS}/${GOARCH}
+build-target: $(BINDIR)/$(GOOS)/$(GOARCH)/$(BINNAME)
+
+$(BINDIR)/$(GOOS)/$(GOARCH)/$(BINNAME): $(SRC)
+	@mkdir -p $(BINDIR)/$(GOOS)/$(GOARCH)
+	@CGO_ENABLED=0 go build -ldflags "$(LDFLAGS)" -o $(BINDIR)/$(GOOS)/$(GOARCH)/$(BINNAME) .
+
+.PHONY: test
+test: build
+	@go test -v ./...
+
+.PHONY: build-cross
+build-cross:
+	@for target in $(TARGETS); do \
+		$(MAKE) build-target GOOS=`echo $$target | cut -d / -f 1` GOARCH=`echo $$target | cut -d / -f 2`; \
+	done
+
+.PHONY: clean
+clean:
+	@rm -rf $(BINDIR)