Interservice communication

docker-compose.yml

@@ -18,11 +18,13 @@ services:
             context: ./machines
             dockerfile: Dockerfile
         environment:
+            - APPPORT=3000
             - DBHOST=db
             - DBPORT=5432
             - DBNAME=komponiranje
             - DBUSER=pero
             - DBPASSWORD=pero.000
+            - PRODUCTSAPPURL=http://products-service:3000
         # ports:
         #     - 3000:3000
         depends_on:
@@ -33,6 +35,7 @@ services:
             context: ./products
             dockerfile: Dockerfile
         environment:
+            - APPPORT=3000
             - DBHOST=db
             - DBPORT=5432
             - DBNAME=komponiranje

machines/app/api/router.go

@@ -2,6 +2,8 @@ package api
 
 import (
 	"fmt"
+	"io"
+	"machines/app/cfg"
 	"machines/app/db"
 	"net/http"
 	"strconv"
@@ -10,9 +12,6 @@ import (
 	"gorm.io/gorm"
 )
 
-const HOST = "0.0.0.0"
-const PORT = 3000
-
 func handlePing(c *gin.Context) {
 	c.JSON(
 		http.StatusOK,
@@ -56,6 +55,44 @@ func handleGetMachine(dbConn *gorm.DB) gin.HandlerFunc {
 	}
 }
 
+func handleGetMachineProducts(dbConn *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		machineId, err := strconv.Atoi(c.Param("machineId"))
+		if err != nil {
+			raiseBadRequestError(c, "Invalid machineId parameter")
+			return
+		}
+
+		machine, err := db.GetMachine(dbConn, machineId)
+		if err != nil {
+			raiseNotFoundError(c, "Machine not found")
+			return
+		}
+
+		url := fmt.Sprintf("%s/products?machineId=%d", cfg.Config.ProductsAppUrl, machine.Id)
+		resp, err := http.Get(url)
+		if err != nil {
+			fmt.Println(err.Error())
+			raiseInternalError(c, err.Error())
+			return
+		}
+
+		if resp.Body != nil {
+			defer resp.Body.Close()
+		}
+
+		body, err := io.ReadAll(resp.Body)
+		if err != nil {
+			fmt.Println(err.Error())
+			raiseInternalError(c, err.Error())
+			return
+		}
+
+		c.Header("Content-Type", "application/json; charset=utf-8")
+		c.Writer.WriteString(string(body))
+	}
+}
+
 func initRouter(dbConn *gorm.DB) *gin.Engine {
 	gin.SetMode(gin.ReleaseMode)
 	router := gin.Default()
@@ -65,13 +102,15 @@ func initRouter(dbConn *gorm.DB) *gin.Engine {
 		routes.GET("/ping", handlePing)
 		routes.GET("", handleGetMachines(dbConn))
 		routes.GET("/:machineId", handleGetMachine(dbConn))
+		routes.GET("/:machineId/products", handleGetMachineProducts(dbConn))
 	}
 
 	return router
 }
 
 func Serve(dbConn *gorm.DB) {
-	serverAddr := fmt.Sprintf("%s:%d", HOST, PORT)
+	serverAddr := fmt.Sprintf("%s:%d", cfg.Config.AppHost, cfg.Config.AppPort)
+	fmt.Printf("Starting serving on %s\n", serverAddr)
 
 	router := initRouter(dbConn)
 	router.Run(serverAddr)

machines/app/cfg/config.go

@@ -5,11 +5,14 @@ import (
 )
 
 type configStruct struct {
+	AppHost        string `default:"0.0.0.0"`
+	AppPort        int    `default:"3000"`
 	DbHost         string `default:"localhost"`
 	DbPort         int    `default:"55432"`
 	DbName         string `default:"komponiranje"`
 	DbUser         string `default:"pero"`
 	DbPassword     string `default:"pero.000"`
+	ProductsAppUrl string `default:"http://localhost:3001"`
 }
 
 const ENV_PREFIX = ""

machines/go.mod

@@ -4,6 +4,7 @@ go 1.21.5
 
 require (
 	github.com/gin-gonic/gin v1.9.1
+	github.com/kelseyhightower/envconfig v1.4.0
 	gorm.io/driver/postgres v1.5.4
 	gorm.io/gorm v1.25.5
 )
@@ -24,7 +25,6 @@ require (
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/kelseyhightower/envconfig v1.4.0 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.4 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/leodido/go-urn v1.2.4 // indirect

products/app/api/router.go

@@ -3,6 +3,7 @@ package api
 import (
 	"fmt"
 	"net/http"
+	"products/app/cfg"
 	"products/app/db"
 	"strconv"
 
@@ -10,9 +11,6 @@ import (
 	"gorm.io/gorm"
 )
 
-const HOST = "0.0.0.0"
-const PORT = 3000
-
 func handlePing(c *gin.Context) {
 	c.JSON(
 		http.StatusOK,
@@ -24,7 +22,22 @@ func handlePing(c *gin.Context) {
 
 func handleGetProducts(dbConn *gorm.DB) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		products := db.GetProducts(dbConn)
+		var (
+			machineId *int = nil
+			err       error
+			mId       int
+		)
+
+		machineIdStr, ok := c.GetQuery("machineId")
+		if ok && len(machineIdStr) > 0 {
+			if mId, err = strconv.Atoi(machineIdStr); err != nil {
+				raiseBadRequestError(c, "Invalid machineId filter")
+				return
+			}
+			machineId = &mId
+		}
+
+		products := db.GetProducts(dbConn, machineId)
 
 		c.JSON(
 			http.StatusOK,
@@ -71,7 +84,8 @@ func initRouter(dbConn *gorm.DB) *gin.Engine {
 }
 
 func Serve(dbConn *gorm.DB) {
-	serverAddr := fmt.Sprintf("%s:%d", HOST, PORT)
+	serverAddr := fmt.Sprintf("%s:%d", cfg.Config.AppHost, cfg.Config.AppPort)
+	fmt.Printf("Starting serving on %s\n", serverAddr)
 
 	router := initRouter(dbConn)
 	router.Run(serverAddr)

products/app/cfg/config.go

@@ -5,6 +5,8 @@ import (
 )
 
 type configStruct struct {
+	AppHost    string `default:"0.0.0.0"`
+	AppPort    int    `default:"3001"`
 	DbHost     string `default:"localhost"`
 	DbPort     int    `default:"55432"`
 	DbName     string `default:"komponiranje"`

products/app/db/repository.go

@@ -2,10 +2,19 @@ package db
 
 import "gorm.io/gorm"
 
-func GetProducts(dbConn *gorm.DB) *[]Product {
+func GetProducts(dbConn *gorm.DB, machineId *int) *[]Product {
-	var products []Product
+	var (
+		products []Product
+		query    = dbConn
+	)
 
-	dbConn.Order("name").Find(&products)
+	if machineId != nil {
+		query = query.
+			Joins("LEFT JOIN machine_products mp ON mp.product_id = products.id").
+			Where("mp.machine_id = ?", machineId)
+	}
+
+	query.Order("name").Find(&products)
 
 	return &products
 }