From fa037166e1dacee2f6b400e306febdc7c30ca474 Mon Sep 17 00:00:00 2001
From: neha_gupta <nehagupta161995@gmail.com>
Date: Fri, 11 Nov 2022 12:58:40 +0530
Subject: [PATCH] Add Fission version API to router for CLI consumption (#2612)

* add version API to router

* return empty struct in case of error in getserverinfo
---
 pkg/fission-cli/util/util.go | 50 ++++++++++++++++++++++++++++--------
 pkg/router/httpTriggers.go   | 20 +++++++++++++++
 2 files changed, 59 insertions(+), 11 deletions(-)

diff --git a/pkg/fission-cli/util/util.go b/pkg/fission-cli/util/util.go
index a3577cc8..f7ecc096 100644
--- a/pkg/fission-cli/util/util.go
+++ b/pkg/fission-cli/util/util.go
@@ -18,8 +18,10 @@ package util
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"io"
+	"net/http"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -39,8 +41,6 @@ import (
 	"k8s.io/client-go/kubernetes"
 
 	fv1 "github.com/fission/fission/pkg/apis/core/v1"
-	"github.com/fission/fission/pkg/controller/client"
-	"github.com/fission/fission/pkg/controller/client/rest"
 	"github.com/fission/fission/pkg/fission-cli/cliwrapper/cli"
 	"github.com/fission/fission/pkg/fission-cli/cmd"
 	"github.com/fission/fission/pkg/fission-cli/console"
@@ -149,20 +149,48 @@ func GetVersion(ctx context.Context, input cli.Input, cmdClient cmd.Client) info
 }
 
 func GetServerInfo(input cli.Input, cmdClient cmd.Client) *info.ServerInfo {
-	serverUrl, err := GetServerURL(input, cmdClient)
-	if err != nil {
-		return &info.ServerInfo{}
-	}
-	restClient := rest.NewRESTClient(serverUrl)
-	client := client.MakeClientset(restClient)
 
-	serverInfo, err := client.V1().Misc().ServerInfo()
+	var serverInfo info.ServerInfo
+	serverURL, err := getRouterURL(input.Context(), cmdClient)
+	if err != nil {
+		console.Warn("could not connect to server")
+		return &serverInfo
+	}
+	// make request
+	resp, err := http.Get(serverURL.String() + "/_version")
+	if err != nil {
+		console.Warn("could not get data from server")
+		return &serverInfo
+	}
+
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		msg := fmt.Sprintf("HTTP error %v", resp.StatusCode)
+		console.Warn(msg)
+		return &serverInfo
+	}
+
+	err = json.NewDecoder(resp.Body).Decode(&serverInfo)
 	if err != nil {
 		console.Warn(fmt.Sprintf("Error getting Fission API version: %v", err))
-		serverInfo = &info.ServerInfo{}
+		serverInfo = info.ServerInfo{}
 	}
 
-	return serverInfo
+	return &serverInfo
+}
+
+func getRouterURL(ctx context.Context, cmdClient cmd.Client) (serverURL *url.URL, err error) {
+	// Portforward to the fission router
+	localRouterPort, err := SetupPortForward(ctx, cmdClient, GetFissionNamespace(), "application=fission-router")
+	if err != nil {
+		return serverURL, err
+	}
+
+	serverURL, err = url.Parse("http://127.0.0.1:" + localRouterPort)
+	if err != nil {
+		return serverURL, err
+	}
+	return serverURL, err
 }
 
 func GetServerURL(input cli.Input, client cmd.Client) (serverUrl string, err error) {
diff --git a/pkg/router/httpTriggers.go b/pkg/router/httpTriggers.go
index 86f1bf48..542e5031 100644
--- a/pkg/router/httpTriggers.go
+++ b/pkg/router/httpTriggers.go
@@ -24,14 +24,17 @@ import (
 
 	"github.com/gorilla/mux"
 	"go.uber.org/zap"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/kubernetes"
 	k8sCache "k8s.io/client-go/tools/cache"
 
 	fv1 "github.com/fission/fission/pkg/apis/core/v1"
+	ferror "github.com/fission/fission/pkg/error"
 	executorClient "github.com/fission/fission/pkg/executor/client"
 	config "github.com/fission/fission/pkg/featureconfig"
 	"github.com/fission/fission/pkg/generated/clientset/versioned"
+	"github.com/fission/fission/pkg/info"
 	"github.com/fission/fission/pkg/throttler"
 	"github.com/fission/fission/pkg/utils"
 	"github.com/fission/fission/pkg/utils/metrics"
@@ -107,6 +110,21 @@ func routerHealthHandler(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusOK)
 }
 
+func versionHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	_, err := w.Write([]byte(info.ApiInfo().String()))
+	if err != nil {
+		se, ok := err.(*kerrors.StatusError)
+		if ok {
+			http.Error(w, se.Error(), int(se.ErrStatus.Code))
+			return
+		}
+
+		code, msg := ferror.GetHTTPError(err)
+		http.Error(w, msg, code)
+	}
+}
+
 func (ts *HTTPTriggerSet) getRouter(fnTimeoutMap map[types.UID]int) *mux.Router {
 
 	featureConfig, _ := config.GetFeatureConfig()
@@ -267,6 +285,8 @@ func (ts *HTTPTriggerSet) getRouter(fnTimeoutMap map[types.UID]int) *mux.Router
 
 	// Healthz endpoint for the router.
 	muxRouter.HandleFunc("/router-healthz", routerHealthHandler).Methods("GET")
+	// version of application.
+	muxRouter.HandleFunc("/_version", versionHandler).Methods("GET")
 
 	return muxRouter
 }