Show fission deployment version with cli (#538)

Add version information to binary through go ldflags

environments/fetcher/cmd/build.sh

@@ -1,2 +1,17 @@
 #!/bin/sh
-CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -gcflags=-trimpath=$GOPATH -asmflags=-trimpath=$GOPATH -o fetcher .
+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 fetcher .

environments/fetcher/cmd/main.go

@@ -71,6 +71,7 @@ func main() {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", fetcher.FetchHandler)
 	mux.HandleFunc("/upload", fetcher.UploadHandler)
+	mux.HandleFunc("/version", fetcher.VersionHandler)
 	mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
 	})

environments/fetcher/fetcher.go

@@ -163,6 +163,11 @@ func writeSecretOrConfigMap(dataMap map[string][]byte, dirPath string) error {
 	return nil
 }
 
+func (fetcher *Fetcher) VersionHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	fmt.Fprintf(w, fission.VersionInfo().String())
+}
+
 func (fetcher *Fetcher) FetchHandler(w http.ResponseWriter, r *http.Request) {
 	if r.Method != "POST" {
 		http.Error(w, "only POST is supported on this endpoint", http.StatusMethodNotAllowed)