Golang Assessment [ added two microservice ]

golang/ASSIGMENT/Makefile

@@ -0,0 +1,5 @@
+generate-proto:
+	rm -f pb/proto/*.pb.go
+	protoc --go_out=pb/ --go_opt=paths=source_relative \
+                                        --go-grpc_out=pb/ --go-grpc_opt=paths=source_relative \
+                                        proto/*.proto

golang/ASSIGMENT/docker-compose.yml

@@ -0,0 +1,10 @@
+version: '3.8'
+
+services:
+  oms:
+    build: ./oms
+    # You can add other configurations for this service
+
+  ums:
+    build: ./ums
+    # You can add other configurations for this service

golang/ASSIGMENT/oms/Dockerfile

@@ -0,0 +1,33 @@
+# Dockerfile References: https://docs.docker.com/engine/reference/builder/
+# Start from the latest golang base image
+FROM golang:1.21.4-alpine3.17 AS builder
+
+
+RUN apk update
+RUN apk add git gcc musl-dev
+RUN apk add curl bash
+
+WORKDIR /go/src/app
+
+# Copy the Go application source code into the container
+COPY . .
+
+# Add Maintainer Info
+LABEL maintainer="Arijit Nayak"
+ENV APP_NAME "oms"
+
+#You can define a variable with:
+#ARG myvalue=3
+# Create work env
+RUN mkdir -p  $GOPATH/src/$CODE_PATH/
+ADD .  $GOPATH/src/$CODE_PATH/
+WORKDIR $GOPATH/src/$CODE_PATH/
+
+# Run go clean?
+RUN go install -tags dynamic ./...
+
+# run the command to start es data service
+CMD $GOPATH/bin/ums
+
+# Expose port 8082 to the outside world
+EXPOSE 5060

golang/ASSIGMENT/oms/Makefile

@@ -0,0 +1,11 @@
+generate-proto:
+	rm -f pb/proto/*.pb.go
+	protoc --go_out=pb/ --go_opt=paths=source_relative \
+                                        --go-grpc_out=pb/ --go-grpc_opt=paths=source_relative \
+                                        proto/*.proto
+db-init:
+	psql -c 'CREATE DATABASE "user-management-service"' -U $(user)
+migrationup:
+    migrate -path db/migrations -database "postgres://$(user):$(password)@$(host):$(port)/user-management-service?sslmode=disable" -verbose up
+migrationdown:
+    migrate -path db/migrations -database "postgres://$(user):$(password)@$(host):$(port)/user-management-service?sslmode=disable" -verbose down

golang/ASSIGMENT/oms/go.mod

@@ -0,0 +1,22 @@
+module oms
+
+go 1.21.4
+
+require (
+	github.com/joho/godotenv v1.5.1
+	github.com/lib/pq v1.10.9
+	github.com/xhit/go-str2duration/v2 v2.1.0
+	github.myproto.com v0.0.0-00010101000000-000000000000
+	google.golang.org/grpc v1.59.0
+)
+
+require (
+	github.com/golang/protobuf v1.5.3 // indirect
+	golang.org/x/net v0.14.0 // indirect
+	golang.org/x/sys v0.11.0 // indirect
+	golang.org/x/text v0.12.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230822172742-b8732ec3820d // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
+)
+
+replace github.myproto.com => ../pb/proto/

golang/ASSIGMENT/oms/go.sum

@@ -0,0 +1,27 @@
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
+github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
+github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/xhit/go-str2duration/v2 v2.1.0 h1:lxklc02Drh6ynqX+DdPyp5pCKLUQpRT8bp8Ydu2Bstc=
+github.com/xhit/go-str2duration/v2 v2.1.0/go.mod h1:ohY8p+0f07DiV6Em5LKB0s2YpLtXVyJfNt1+BlmyAsU=
+golang.org/x/net v0.14.0 h1:BONx9s002vGdD9umnlX1Po8vOZmrgH34qlHcD1MfK14=
+golang.org/x/net v0.14.0/go.mod h1:PpSgVXXLK0OxS0F31C1/tv6XNguvCrnXIDrFMspZIUI=
+golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
+golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
+golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20230822172742-b8732ec3820d h1:uvYuEyMHKNt+lT4K3bN6fGswmK8qSvcreM3BwjDh+y4=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20230822172742-b8732ec3820d/go.mod h1:+Bk1OCOj40wS2hwAMA+aCW9ypzm63QTBBHp6lQ3p+9M=
+google.golang.org/grpc v1.59.0 h1:Z5Iec2pjwb+LEOqzpB2MR12/eKFhDPhuqW91O+4bwUk=
+google.golang.org/grpc v1.59.0/go.mod h1:aUPDwccQo6OTjy7Hct4AfBPD1GptF4fyUjIkQ9YtF98=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
+google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=

golang/ASSIGMENT/oms/main.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"os"
+	"os/signal"
+	"time"
+
+	"oms/pkg/db"
+	"oms/pkg/domain"
+	grpcPkg "oms/pkg/grpc"
+	"oms/pkg/grpchandler"
+
+	"github.com/joho/godotenv"
+	strToDuration "github.com/xhit/go-str2duration/v2"
+)
+
+var (
+	// Derived from ldflags -X
+	buildRevision string
+	buildVersion  string
+	buildTime     string
+	// general options
+	versionFlag bool
+	helpFlag    bool
+	// timeout flag
+	timeout int
+	// grpc server port
+	grpcServerPort string
+	postgresURI    string
+	// retryInterval for db connection
+	retryInterval string
+	// program controller
+	done    = make(chan struct{})
+	errGrpc = make(chan error)
+)
+
+func init() {
+	err := godotenv.Load()
+	if err != nil {
+		log.Println(".env file not found")
+	}
+	flag.BoolVar(&versionFlag, "version", false, "show current version and exit")
+	flag.BoolVar(&helpFlag, "help", false, "show usage and exit")
+	flag.StringVar(&grpcServerPort, "grpcServerPort", ":5060", "grpc server port")
+	flag.IntVar(&timeout, "timeout", 1, "timeout for db connection")
+	postgresURI = os.Getenv("POSTGRESQL_DB_URL")
+	if postgresURI == "" {
+		log.Fatal("postgres db url not found")
+	}
+	if retryInterval = os.Getenv("RETRY_INTERVAL"); len(retryInterval) == 0 {
+		log.Println("retry interval for db connection not found !")
+		return
+	}
+}
+
+func setBuildVariables() {
+	if buildRevision == "" {
+		buildRevision = "dev"
+	}
+	if buildVersion == "" {
+		buildVersion = "dev"
+	}
+	if buildTime == "" {
+		buildTime = time.Now().UTC().Format(time.RFC3339)
+	}
+}
+
+func parseFlags() {
+	flag.Parse()
+	if helpFlag {
+		flag.Usage()
+		os.Exit(0)
+	}
+	if versionFlag {
+		log.Printf("%s %s %s\n", buildRevision, buildVersion, buildTime)
+		os.Exit(0)
+	}
+}
+
+func handleInterrupts() {
+	log.Println("start handle interrupts")
+	interrupt := make(chan os.Signal, 1)
+	signal.Notify(interrupt, os.Interrupt)
+	sig := <-interrupt
+	log.Printf("caught sig: %v", sig)
+	// close resource here
+	done <- struct{}{}
+}
+
+func main() {
+	log.SetFlags(log.LstdFlags | log.Lshortfile)
+	setBuildVariables()
+	parseFlags()
+	go handleInterrupts()
+	log.SetFlags(log.LstdFlags | log.Lshortfile)
+	retryIntervalDuration, err := strToDuration.ParseDuration(retryInterval)
+	if err != nil {
+		log.Fatal("unable to parse string to duration : ", err)
+	}
+	postgreSQL := db.Connect2DB(postgresURI, retryIntervalDuration)
+	defer postgreSQL.Close()
+
+	d := domain.NewOrderCliet(postgreSQL, timeout)
+
+	grpcHandler := grpchandler.NewGrpcHandler(d)
+	grpcServer := grpcPkg.NewGrpcServer(grpcServerPort, grpcHandler)
+	go func() {
+		log.Printf("GRPC sever running on port: %v\n", grpcServerPort)
+		errGrpc <- grpcServer.ListenAndServe()
+	}()
+	select {
+	case err := <-errGrpc:
+		log.Print("Grpc error", err)
+	case <-done:
+		log.Println("shutting down server ...")
+	}
+	time.AfterFunc(1*time.Second, func() {
+		close(done)
+		close(errGrpc)
+	})
+}

golang/ASSIGMENT/oms/pkg/db/db.go

@@ -0,0 +1,15 @@
+package db
+
+import (
+	"context"
+	"database/sql"
+)
+
+// Database ...
+type Database interface {
+	PingContext(ctx context.Context) error
+	Exec(query string, args ...interface{}) (sql.Result, error)
+	Close() error
+	QueryRow(query string, args ...interface{}) *sql.Row
+	Query(query string, args ...interface{}) (*sql.Rows, error)
+}

golang/ASSIGMENT/oms/pkg/db/migrations/000001_Add_Order_Table.down.sql

@@ -0,0 +1,6 @@
+BEGIN;
+DROP TABLE IF EXISTS "orders";
+DROP FUNCTION IF EXISTS update_modified_column;
+DROP TRIGGER [IF EXISTS] update_order
+ON "orders" [ CASCADE | RESTRICT ];
+COMMIT;

golang/ASSIGMENT/oms/pkg/db/migrations/000001_Add_Order_Table.up.sql

@@ -0,0 +1,25 @@
+BEGIN;
+
+CREATE TYPE ORDER_STAUTS IF NOT EXISTS AS ENUM('INITIALIZED','PROCESSING','SHIPPED','DELIVERED');
+
+CREATE TABLE IF NOT EXISTS "orders" (
+    "ID" SERIAL PRIMARY KEY,
+    "buyerUserID" VARCHAR NOT NULL,
+    "status" ORDER_STAUTS NOT NULL,
+    "totalAmount" NUMERIC NOT NULL,
+    "products" JSONB,
+    "paymentID" VARCHAR NOT NULL,
+    "createdAt" TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    "updatedAt" TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+);
+
+CREATE OR REPLACE FUNCTION update_modified_column()
+RETURNS TRIGGER AS $$
+BEGIN
+    NEW."updatedAt" = now();
+    RETURN NEW;
+END;
+
+CREATE TRIGGER update_order BEFORE UPDATE ON "orders" FOR EACH ROW EXECUTE PROCEDURE update_modified_column();
+
+COMMIT;

golang/ASSIGMENT/oms/pkg/db/postgres.go

@@ -0,0 +1,30 @@
+package db
+
+import (
+	"database/sql"
+	"log"
+	"time"
+
+	_ "github.com/lib/pq"
+)
+
+// QuitRetry is the exit point for retrying from a infinite loop
+var QuitRetry = make(chan bool)
+
+// Connect2DB extablish the connection to the database
+func Connect2DB(connStr string, dbRetry time.Duration) *sql.DB {
+	for {
+		select {
+		case <-QuitRetry:
+			return nil
+		case <-time.After(dbRetry):
+			DB, err := sql.Open("postgres", connStr)
+			if err != nil {
+				log.Println("failed to connect to database: ", err)
+			} else {
+				return DB
+			}
+			log.Printf("reconnecting to database, after: %v milliseconds\n", dbRetry)
+		}
+	}
+}

golang/ASSIGMENT/oms/pkg/domain/domain.go

@@ -0,0 +1,31 @@
+package domain
+
+import (
+	"oms/pkg/models"
+
+	"oms/pkg/db"
+)
+
+// Order ...
+type Order interface {
+	GetHealth() bool
+	CreateOrder(order *models.Order) (string, error)
+	GetOrdersByUserID(userID string) ([]models.Order, error)
+	DeleteOrderByUserID(userID string) error
+	DeleteOrderByOrderID(orderID string) error
+	GetOrder(orderID string) (*models.Order, error)
+}
+
+// UserClient ...
+type OrderCliet struct {
+	DB      db.Database
+	Timeout int
+}
+
+// NewUserClient ...
+func NewOrderCliet(db db.Database, timeout int) *OrderCliet {
+	return &OrderCliet{
+		DB:      db,
+		Timeout: timeout,
+	}
+}

golang/ASSIGMENT/oms/pkg/domain/errors.go

@@ -0,0 +1,18 @@
+package domain
+
+import "errors"
+
+var (
+	// ErrOrderCreationFailed ...
+	ErrOrderCreationFailed = errors.New("failed to create the order")
+	// ErrInvalidData ...
+	ErrInvalidData = errors.New("invalid data received from the client")
+	// ErrOrderNotFound ...
+	ErrOrderNotFound = errors.New("requested order not found")
+	// ErrInternalError ...
+	ErrInternalError = errors.New("internal error")
+	// ErrFailedToDeleteOrders ...
+	ErrFailedToDeleteOrders = errors.New("failed to delete all the orders under the specified userID")
+	// ErrFailedToDeleteOrder ...
+	ErrFailedToDeleteOrder = errors.New("failed to delete the order")
+)

golang/ASSIGMENT/oms/pkg/domain/health.go

@@ -0,0 +1,19 @@
+package domain
+
+import (
+	"context"
+	"log"
+	"time"
+)
+
+// GetHealth checks if the the database connection is live or not
+func (d *OrderCliet) GetHealth() bool {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(d.Timeout)*time.Second)
+	defer cancel()
+	err := d.DB.PingContext(ctx)
+	if err != nil {
+		log.Println("failed to connect to database : ", err)
+		return false
+	}
+	return true
+}