67 changes: 67 additions & 0 deletions go.mod
@@ -0,0 +1,67 @@
module github.com/hiteshrepo/grpc-loadbalancing

go 1.19

require (
github.com/gin-gonic/gin v1.9.0
google.golang.org/grpc v1.55.0
google.golang.org/protobuf v1.30.0
k8s.io/client-go v0.27.1
)

require (
github.com/bytedance/sonic v1.8.8 // indirect
github.com/chenzhuoyu/base64x v0.0.0-20221115062448-fe3a3abad311 // indirect
github.com/davecgh/go-spew v1.1.1 // indirect
github.com/emicklei/go-restful/v3 v3.10.2 // indirect
github.com/gin-contrib/sse v0.1.0 // indirect
github.com/go-logr/logr v1.2.4 // indirect
github.com/go-openapi/jsonpointer v0.19.6 // indirect
github.com/go-openapi/jsonreference v0.20.2 // indirect
github.com/go-openapi/swag v0.22.3 // indirect
github.com/go-playground/locales v0.14.1 // indirect
github.com/go-playground/universal-translator v0.18.1 // indirect
github.com/go-playground/validator/v10 v10.13.0 // indirect
github.com/goccy/go-json v0.10.2 // indirect
github.com/gogo/protobuf v1.3.2 // indirect
github.com/golang/protobuf v1.5.3 // indirect
github.com/google/gnostic v0.6.9 // indirect
github.com/google/go-cmp v0.5.9 // indirect
github.com/google/gofuzz v1.2.0 // indirect
github.com/google/uuid v1.3.0 // indirect
github.com/imdario/mergo v0.3.15 // indirect
github.com/josharian/intern v1.0.0 // indirect
github.com/json-iterator/go v1.1.12 // indirect
github.com/klauspost/cpuid/v2 v2.2.4 // indirect
github.com/leodido/go-urn v1.2.4 // indirect
github.com/mailru/easyjson v0.7.7 // indirect
github.com/mattn/go-isatty v0.0.18 // indirect
github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
github.com/modern-go/reflect2 v1.0.2 // indirect
github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
github.com/pelletier/go-toml/v2 v2.0.7 // indirect
github.com/spf13/pflag v1.0.5 // indirect
github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
github.com/ugorji/go/codec v1.2.11 // indirect
golang.org/x/arch v0.3.0 // indirect
golang.org/x/crypto v0.9.0 // indirect
golang.org/x/net v0.10.0 // indirect
golang.org/x/oauth2 v0.8.0 // indirect
golang.org/x/sys v0.8.0 // indirect
golang.org/x/term v0.8.0 // indirect
golang.org/x/text v0.9.0 // indirect
golang.org/x/time v0.3.0 // indirect
google.golang.org/appengine v1.6.7 // indirect
google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
gopkg.in/inf.v0 v0.9.1 // indirect
gopkg.in/yaml.v2 v2.4.0 // indirect
gopkg.in/yaml.v3 v3.0.1 // indirect
k8s.io/api v0.27.1 // indirect
k8s.io/apimachinery v0.27.1 // indirect
k8s.io/klog/v2 v2.100.1 // indirect
k8s.io/kube-openapi v0.0.0-20230501164219-8b0f38b5fd1f // indirect
k8s.io/utils v0.0.0-20230505201702-9f6742963106 // indirect
sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd // indirect
sigs.k8s.io/structured-merge-diff/v4 v4.2.3 // indirect
sigs.k8s.io/yaml v1.3.0 // indirect
)
334 changes: 334 additions & 0 deletions go.sum

Large diffs are not rendered by default.

110 changes: 110 additions & 0 deletions internal/app/greetclient/app.go
@@ -0,0 +1,110 @@
package greetclient

import (
"context"
"fmt"
"log"
"net/http"
"os"

"github.com/gin-gonic/gin"
"github.com/hiteshrepo/grpc-loadbalancing/internal/pkg/proto"
"google.golang.org/grpc"
)

type App struct {
client proto.GreetServiceClient
conn *grpc.ClientConn
}

type GreetingRequest struct {
FirstName string `json:"first_name"`
LastName string `json:"last_name"`
}

func (a *App) Start() {
err := a.setupGreetClient()
if err != nil {
log.Printf("could not setup greet client: %v", err)
return
}

fmt.Println("Starting gateway")

router := gin.Default()
router.POST("/greet", a.greet)

port := "9091"
if len(os.Getenv("GATEWAY_PORT")) > 0 {
port = os.Getenv("GATEWAY_PORT")
}

fmt.Println("Starting REST Gateway")

router.Run(fmt.Sprintf("0.0.0.0:%s", port))
}

func (a *App) setupGreetClient() error {
var err error

fmt.Println("Starting greet client")

opts := grpc.WithInsecure()
serverHost := "localhost"
serverPort := "50051"

if host, ok := os.LookupEnv("GRPC_SERVER_HOST"); ok {
serverHost = host
}

if port, ok := os.LookupEnv("GRPC_SERVER_PORT"); ok {
serverPort = port
}

servAddr := fmt.Sprintf("%s:%s", serverHost, serverPort)

fmt.Println("dialing", servAddr)

a.conn, err = grpc.Dial(
servAddr,
opts,
)
if err != nil {
log.Printf("could not connect: %v", err)
return err
}

a.client = proto.NewGreetServiceClient(a.conn)

return nil
}

func (a *App) Shutdown() {
a.conn.Close()
}

func (a *App) doUnary(firstName, lastName string) string {
req := &proto.GreetingRequest{
Greeting: &proto.Greeting{
FirstName: firstName,
LastName: lastName,
},
}
res, err := a.client.Greet(context.Background(), req)
if err != nil {
log.Fatalf("error while calling greet rpc : %v", err)
}
return fmt.Sprintf("reponse from Greet rpc: %v", res.Result)
}

func (a *App) greet(c *gin.Context) {
fmt.Println("got request - REST Gateway")

var gr GreetingRequest
if err := c.BindJSON(&gr); err != nil {
return
}

resp := a.doUnary(gr.FirstName, gr.LastName)
c.String(http.StatusOK, resp)
}
62 changes: 62 additions & 0 deletions internal/app/greetserver/app.go
@@ -0,0 +1,62 @@
package greetserver

import (
"context"
"fmt"
"log"
"net"
"os"

"github.com/hiteshrepo/grpc-loadbalancing/internal/pkg/proto"
"google.golang.org/grpc"
)

type App struct {
proto.UnimplementedGreetServiceServer
}

func (a *App) Start() {
fmt.Println("Starting greet server")

port := "50051"
if len(os.Getenv("GRPC_PORT")) > 0 {
port = os.Getenv("GRPC_PORT")
}

servAddr := fmt.Sprintf("0.0.0.0:%s", port)

lis, err := net.Listen("tcp", servAddr)
if err != nil {
log.Fatalf("Failed to listen: %v", err)
}
opts := []grpc.ServerOption{}
s := grpc.NewServer(opts...)
proto.RegisterGreetServiceServer(s, &App{})
if err := s.Serve(lis); err != nil {
log.Fatalf("Failed to serve: %v", err)
}
}

func (a *App) Shutdown() {

}

func (a *App) Greet(_ context.Context, req *proto.GreetingRequest) (*proto.GreetingResponse, error) {
firstName := req.GetGreeting().GetFirstName()
lastName := req.GetGreeting().GetLastName()

var podIp string
var podName string
if len(os.Getenv("POD_IP")) > 0 {
podIp = os.Getenv("POD_IP")
}

if len(os.Getenv("POD_NAME")) > 0 {
podName = os.Getenv("POD_NAME")
}

result := fmt.Sprintf("Hello, %s %s from pod: name(%s), ip(%s).", firstName, lastName, podName, podIp)
return &proto.GreetingResponse{
Result: result,
}, nil
}
287 changes: 287 additions & 0 deletions internal/pkg/proto/greet.pb.go
22 changes: 22 additions & 0 deletions internal/pkg/proto/greet.proto
@@ -0,0 +1,22 @@
syntax = "proto3";

package greet;
option go_package="./proto";

message Greeting {
string first_name = 1;
string last_name = 2;
}

message GreetingRequest {
Greeting greeting = 1;
}

message GreetingResponse {
string Result = 1;
}

service GreetService{
// Unary
rpc Greet(GreetingRequest) returns (GreetingResponse) {};
}
107 changes: 107 additions & 0 deletions internal/pkg/proto/greet_grpc.pb.go