Add new examples to kompose (#1803)

#### What type of PR is this?

<!--
Add one of the following kinds:
/kind bug
/kind documentation
/kind feature
-->

/kind cleanup

#### What this PR does / why we need it:

Fixes the current broken examples by:

* Removing all the old incompatible ones (we do not really support v3
  anymore or v2... since switching libraries)
* Uses quay.io/kompose/web as our front end example which is a fork of
  the guestbook-go kubernetes examples

#### Which issue(s) this PR fixes:
<!--
*Automatically closes linked issue when PR is merged.
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
-->

Closes https://github.com/kubernetes/kompose/issues/1757

#### Special notes for your reviewer:

Test using docker-compose (you'll see it come up!), then try with
kompose :)

Signed-off-by: Charlie Drage <charlie@charliedrage.com>

examples/web/main.go

@@ -0,0 +1,133 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/codegangsta/negroni"
+	"github.com/gorilla/mux"
+	"github.com/xyproto/simpleredis/v2"
+)
+
+var (
+	leaderPool   *simpleredis.ConnectionPool
+	replicaPools []*simpleredis.ConnectionPool
+)
+
+func ListRangeHandler(rw http.ResponseWriter, req *http.Request) {
+	key := mux.Vars(req)["key"]
+	var members []string
+	var err error
+	for _, replicaPool := range replicaPools {
+		list := simpleredis.NewList(replicaPool, key)
+		members, err = list.GetAll()
+		if err == nil {
+			break // Found a replica with data, exit loop
+		}
+	}
+	if err != nil {
+		http.Error(rw, "Failed to retrieve data from replicas", http.StatusInternalServerError)
+		return
+	}
+
+	membersJSON, err := json.MarshalIndent(members, "", "  ")
+	if err != nil {
+		http.Error(rw, "Failed to marshal JSON", http.StatusInternalServerError)
+		return
+	}
+
+	rw.Write(membersJSON)
+}
+
+func ListPushHandler(rw http.ResponseWriter, req *http.Request) {
+	key := mux.Vars(req)["key"]
+	value := mux.Vars(req)["value"]
+	list := simpleredis.NewList(leaderPool, key)
+	HandleError(nil, list.Add(value))
+	ListRangeHandler(rw, req)
+}
+
+func InfoHandler(rw http.ResponseWriter, req *http.Request) {
+	info := HandleError(leaderPool.Get(0).Do("INFO")).([]byte)
+	rw.Write(info)
+}
+
+func EnvHandler(rw http.ResponseWriter, req *http.Request) {
+	environment := make(map[string]string)
+	for _, item := range os.Environ() {
+		splits := strings.Split(item, "=")
+		key := splits[0]
+		val := strings.Join(splits[1:], "=")
+		environment[key] = val
+	}
+
+	envJSON := HandleError(json.MarshalIndent(environment, "", "  ")).([]byte)
+	rw.Write(envJSON)
+}
+
+func HandleError(result interface{}, err error) (r interface{}) {
+	if err != nil {
+		panic(err)
+	}
+	return result
+}
+
+func getReplicaPool() *simpleredis.ConnectionPool {
+	// Use the first replica as the primary replica for read operations
+	return replicaPools[0]
+}
+
+func main() {
+	// Read the Redis replica addresses from an environment variable
+	replicaAddresses := os.Getenv("REDIS_REPLICAS")
+	if replicaAddresses == "" {
+		// Use default values if not set
+		replicaAddresses = "redis-replica"
+	}
+
+	// Read the Redis port number from an environment variable
+	redisPort := os.Getenv("REDIS_PORT")
+	if redisPort == "" {
+		// Use default port if not set
+		redisPort = "6379"
+	}
+
+	// Read the Redis leader address from an environment variable
+	redisLeaderAddress := os.Getenv("REDIS_LEADER")
+	if redisLeaderAddress == "" {
+		// Use default leader address if not set
+		redisLeaderAddress = "redis-leader"
+	}
+
+	// Read the server port number from an environment variable
+	serverPort := os.Getenv("SERVER_PORT")
+	if serverPort == "" {
+		// Use default port if not set
+		serverPort = "8080"
+	}
+
+	// Construct the Redis leader and replica addresses
+	leaderAddress := redisLeaderAddress + ":" + redisPort
+	replicaAddressesArr := strings.Split(replicaAddresses, ",")
+	replicaPools = make([]*simpleredis.ConnectionPool, len(replicaAddressesArr))
+	for i, addr := range replicaAddressesArr {
+		replicaPools[i] = simpleredis.NewConnectionPoolHost(addr + ":" + redisPort)
+		defer replicaPools[i].Close()
+	}
+
+	// Create a connection pool for the leader using the constructed address
+	leaderPool = simpleredis.NewConnectionPoolHost(leaderAddress)
+	defer leaderPool.Close()
+
+	r := mux.NewRouter()
+	r.Path("/lrange/{key}").Methods("GET").HandlerFunc(ListRangeHandler)
+	r.Path("/rpush/{key}/{value}").Methods("GET").HandlerFunc(ListPushHandler)
+	r.Path("/info").Methods("GET").HandlerFunc(InfoHandler)
+	r.Path("/env").Methods("GET").HandlerFunc(EnvHandler)
+
+	n := negroni.Classic()
+	n.UseHandler(r)
+	n.Run(":" + serverPort)
+}