Merge pull request prometheus-community#6 from nlamirault/version-flag

Add: flag to print version of the application

Author: ncabatoff

Makefile

@@ -5,6 +5,8 @@ GO_SRC := dbms_exporter.go $(shell find ${GO_DIRS} -name '*.go')
 CONTAINER_NAME = ncabatoff/dbms_exporter:latest
 FREETDS_VERSION = 1.1.5
 BUILD_CONTAINER_NAME = ncabatoff/dbms_exporter_builder:${FREETDS_VERSION}
+TAG_VERSION ?= $(shell git describe --tags --abbrev=0)
+
 # Possible BUILDTAGS settings are postgres, freetds, and odbc.
 DRIVERS = postgres freetds
 # Use make LDFLAGS= if you want to build with tag ODBC.
@@ -14,7 +16,7 @@ all: vet test dbms_exporter
 
 # Simple go build
 dbms_exporter: $(GO_SRC)
-	go build -ldflags '$(LDFLAGS) -X main.Version=git:$(shell git rev-parse HEAD)' -o dbms_exporter -tags '$(DRIVERS)' .
+	go build -ldflags '$(LDFLAGS) -X main.Version=$(TAG_VERSION)' -o dbms_exporter -tags '$(DRIVERS)' .
 
 docker: Dockerfile $(GO_SRC)
 	docker build --build-arg drivers="$(DRIVERS)" --build-arg ldflags="$(LDFLAGS)" -t $(CONTAINER_NAME) .
@@ -24,7 +26,7 @@ vet:
 
 test:
 	go test -v . ./config ./common ./db ./recipes
- 
+
 test-integration:
 	tests/test-smoke
 

dbms_exporter.go

@@ -19,9 +19,11 @@ import (
 	"github.com/prometheus/common/log"
 )
 
-var Version string = "0.0.1"
+// Version is set at build time use ldflags.
+var Version string
 
 var (
+	version       = flag.Bool("version", false, "print version and exit")
 	listenAddress = flag.String(
 		"web.listen-address", ":9113",
 		"Address to listen on for web interface and telemetry.",
@@ -458,6 +460,10 @@ func main() {
 		fmt.Fprintf(os.Stderr, usage)
 	}
 	flag.Parse()
+	if *version {
+		fmt.Printf("dbms-exporter version %s\n", Version)
+		os.Exit(0)
+	}
 
 	if *queriesPath == "" {
 		log.Fatalf("-queryfile is a required argument")
@@ -508,7 +514,7 @@ func main() {
 
 var usage = `
 The DATA_SOURCE_NAME enviroment variable specifies connection details.  Examples:
-	
+
   Sybase FreeTDS example (driver=freetds):
 	compatibility_mode=sybase;user=myuser;pwd=mypassword;server=myhostname