Show fission deployment version with cli (#538)

Add version information to binary through go ldflags

builder/cmd/build.sh

@@ -1,3 +1,18 @@
 #!/bin/bash
-CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -gcflags=-trimpath=$GOPATH -asmflags=-trimpath=$GOPATH -o builder .
+version=$1
+if [ -z $version ]; then
+    version=$(git rev-parse HEAD)
+fi
+
+date=$2
+if [ -z $date ]; then
+    date=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+fi
+
+gitcommit=$3
+if [ -z $gitcommit ]; then
+    gitcommit=$(git rev-parse HEAD)
+fi
+
+CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -gcflags=-trimpath=$GOPATH -asmflags=-trimpath=$GOPATH -ldflags "-X github.com/fission/fission.GitCommit=$gitcommit -X github.com/fission/fission.BuildDate=$date -X github.com/fission/fission.Version=$version" -o builder .
 

builder/cmd/main.go

@@ -38,6 +38,7 @@ func main() {
 	builder := builder.MakeBuilder(dir)
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", builder.Handler)
+	mux.HandleFunc("/version", builder.VersionHandler)
 	mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
 	})