Integrate version numbering with govvv

See: https://oddcode.daveamit.com/2018/08/17/embed-versioning-information-in-golang-binary/

build.sh

@@ -2,14 +2,54 @@
 
 TARGET=mqttListener
 
+export PATH=$PATH:~/go/bin
 
 
+
+
+
+
+
+
+RED='\e[0;31m'
+GREEN='\e[0;32m'
+LIGHT_YELLOW='\e[93m'
+NC='\e[0m' # No Color
+BOLD='\e[1m'
+NORMAL='\e[21m'
+
+
+
+#######################################################################################
+# functions
+
+die() { echo -e "\n${RED}$@${NC}" 1>&2 ; exit 1; }
+
+
+
+#######################################################################################
+
 #cd /src
 
+if ! command -v govvv &> /dev/null ; then
+	die "govv is not installed"	
+fi	
 
 
-echo "Building for Linux 64-bit"
-env GOOS=linux GOARCH=amd64 go build -o ${TARGET}-linux-amd64
 
-echo "Building for arm"
-env GOOS=linux GOARCH=arm go build -o ${TARGET}-linux-arm
+#######################################################################################
+# build
+echo -e "${NC}\n "
+
+echo -e "\nBuilding for Linux 64-bit:"
+env GOOS=linux GOARCH=amd64 go build -a -v -ldflags "$(govvv -flags)" -o ${TARGET}-linux-amd64
+echo -e "\t\t${GREEN}... done${NC}"
+
+
+echo -e "\nBuilding for arm:"
+env GOOS=linux GOARCH=arm go build -a -v -ldflags "$(govvv -flags)" -o ${TARGET}-linux-arm
+echo -e "\t\t${GREEN}... done${NC}"
+
+echo -e "\nstipping arm binary:"
+strip -o ${TARGET}-linux-arm-stripped ${TARGET}-linux-arm
+echo -e "\t\t${GREEN}... done${NC}"

go.mod

@@ -3,6 +3,7 @@ module mqttListener
 go 1.14
 
 require (
+	github.com/ahmetb/govvv v0.3.0 // indirect
 	github.com/eclipse/paho.mqtt.golang v1.2.0
 	github.com/mattn/go-sqlite3 v1.14.2
 	github.com/mmcdole/gofeed v1.0.0

main.go

@@ -11,13 +11,50 @@ import (
 
 	"os"
 	"os/signal"
+	"path/filepath"
 	"syscall"
 
 	"net/http"
 )
 
+// ---------------------------------------------------------------------------
+// Following variables will be statically linked at the time of compiling
+
+// GitCommit holds short commit hash of source tree
+var GitCommit string
+
+// GitBranch holds current branch name the code is built off
+var GitBranch string
+
+// GitState shows whether there are uncommitted changes
+var GitState string
+
+// GitSummary holds output of git describe --tags --dirty --always
+var GitSummary string
+
+// BuildDate holds RFC3339 formatted UTC date (build time)
+var BuildDate string
+
+// Version holds contents of ./VERSION file, if exists, or the value passed via the -version option
+var Version string
+
+func PrintVersion() {
+	var versionString string = GitSummary
+	fmt.Println("\n--------------------------------------------------------")
+	fmt.Println(filepath.Base(os.Args[0]), " Version Information: ")
+	fmt.Println("\tVersion:\t", versionString)
+	fmt.Println("\tBranch:\t\t", GitBranch)
+	fmt.Println("\tCommit-ID:\t", GitCommit)
+	fmt.Println("\tBuilt:\t\t", BuildDate)
+	fmt.Println("\n--------------------------------------------------------")
+	fmt.Println("")
+}
+
+// ---------------------------------------------------------------------------
 func main() {
 
+	PrintVersion()
+
 	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt, syscall.SIGTERM)