migrate to golang from node.js

.circleci/config.yml

@@ -10,10 +10,10 @@ jobs:
       - setup_remote_docker
       - run:
           name: Build Docker image
-          command: docker build -t app .
+          command: docker build --target target_for_development -t app .
       - run:
           name: Test Docker image
-          command: docker run -it --rm app bash -c "yarn && yarn test"
+          command: docker run -it --rm app bash -c "go test"
   frontend:
     docker:
       - image: circleci/node:12.12.0-buster

Dockerfile

@@ -1,9 +1,10 @@
-FROM golang:1.13.4-buster
-
 ###############################
-# pict
+# for development
 ###############################
 
+### pict ###
+FROM golang:1.13.4-buster AS target_for_development
+
 RUN apt update
 RUN apt -y install clang
 RUN which clang
@@ -15,8 +16,33 @@ WORKDIR /root/pict
 RUN make && install ./pict /usr/bin
 RUN which pict
 
-# for auto reload
+### golang ###
+RUN go get github.com/gin-contrib/cors
+RUN go get github.com/gin-contrib/gzip
+RUN go get github.com/gin-gonic/gin
+RUN go get github.com/stretchr/testify/assert
+
+# to enable auto reloading while developing
 RUN go get github.com/pilu/fresh
 
+COPY main.go /go/src/github.com/junkboy0315/pairwise-pict-online/
+COPY main_test.go /go/src/github.com/junkboy0315/pairwise-pict-online/
+WORKDIR /go/src/github.com/junkboy0315/pairwise-pict-online
+
 # start server
-CMD go run main.go
+CMD ["fresh"]
+
+###############################
+# for production
+###############################
+
+FROM target_for_development AS target_for_compilation
+RUN CGO_ENABLED=0 GOOS=linux go build -v -o server
+
+# Use clean image for a lean production container.
+# https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
+FROM debian:buster-20191014-slim AS target_for_production
+COPY --from=target_for_compilation /root/pict/pict /usr/bin/
+RUN which pict
+COPY --from=target_for_compilation /go/src/github.com/junkboy0315/pairwise-pict-online/server /server
+CMD ["/server"]

README.md

@@ -4,12 +4,3 @@
 
 An online service that easily generates pair-wise test cases.
 It's powered by [Microsoft Pict](https://github.com/microsoft/pict) under the hood.
-
-## Deployment
-
-NOTE: This section is a personal memo.
-
-```sh
-gcloud config set project pairwise-pict-online
-gcloud builds submit --tag asia.gcr.io/pairwise-pict-online/pict-api .
-```

docker-compose.prod.yml

@@ -0,0 +1,30 @@
+version: '3.4'
+services:
+  pict_api_prod:
+    build:
+      context: .
+      target: target_for_production
+    environment:
+      NODE_ENV: production
+    container_name: pict_api_prod
+    volumes:
+      - .:/go/src/github.com/junkboy0315/pairwise-pict-online
+    working_dir: /go/src/github.com/junkboy0315/pairwise-pict-online
+    ports:
+      - '8080:8080'
+  # following frontend will not work because
+  # browsers doe's not support CORS on localhost.
+  # CORS should be disabled to test production builds on local environment.
+  # https://stackoverflow.com/a/10892392/6574720
+  pict_react_prod:
+    image: node:12.12.0-alpine
+    container_name: pict_react_prod
+    environment:
+      NODE_ENV: development # run frontend as dev mode to point to the local API
+    volumes:
+      - ./front:/root/front
+      - /root/front/node_modules/
+    working_dir: /root/front
+    ports:
+      - '3000:3000'
+    command: sh -c 'yarn && yarn start'

docker-compose.yml

@@ -1,14 +1,15 @@
-# This file is only used in the development enviroment
-
-version: '3.3'
+version: '3.4'
 services:
   pict_api:
-    build: .
+    build:
+      context: .
+      target: target_for_development
     environment:
       NODE_ENV: development
     container_name: pict_api
     volumes:
-      - .:/go/src/github.com/junkboy0315/pairwise-pict-online
+      - ./:/go/src/github.com/junkboy0315/pairwise-pict-online/
+      - /go/src/github.com/junkboy0315/pairwise-pict-online/front # to ignore front/node_modules
     working_dir: /go/src/github.com/junkboy0315/pairwise-pict-online
     command: fresh # run `main.go` with auto reload
     ports:
@@ -23,8 +24,6 @@ services:
       - ./front:/root/front
       - /root/front/node_modules/
     working_dir: /root/front
-    depends_on:
-      - pict_api
     ports:
       - '3000:3000'
     command: sh -c 'yarn && yarn start'

main.go

@@ -1,15 +1,88 @@
 package main
 
 import (
-	"fmt"
-	"net/http"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+
+	"github.com/gin-contrib/cors"
+	"github.com/gin-contrib/gzip"
+	"github.com/gin-gonic/gin"
 )
 
-func handler(w http.ResponseWriter, r *http.Request) {
-	fmt.Fprintf(w, "Hello, World")
+type GenerateCasesRequestBody struct {
+	Factors string `json:"factors"`
+}
+
+func SetupRouter() *gin.Engine {
+	// set gin as release mode
+	if os.Getenv("NODE_ENV") != "development" {
+		gin.SetMode(gin.ReleaseMode)
+	}
+
+	router := gin.Default()
+
+	// CORS settings
+	// https://github.com/gin-contrib/cors#using-defaultconfig-as-start-point
+	config := cors.DefaultConfig()
+	config.AllowOrigins = []string{
+		"*",
+	}
+	if os.Getenv("NODE_ENV") != "development" {
+		config.AllowOrigins = []string{
+			"https://pairwise.yuuniworks.com",
+		}
+	}
+	router.Use(cors.New(config))
+
+	// enable gzip
+	router.Use(gzip.Gzip(gzip.DefaultCompression))
+
+	router.GET("/", func(c *gin.Context) {
+		c.String(200, "ok")
+	})
+
+	router.POST("/generate_cases", func(c *gin.Context) {
+		// extract request body
+		var generateCasesRequestBody GenerateCasesRequestBody
+		c.BindJSON(&generateCasesRequestBody)
+
+		// create temporary test-factors file
+		factors := []byte(generateCasesRequestBody.Factors)
+		tmpfile, err := ioutil.TempFile("", "temp-test-factors-")
+		if err != nil {
+			log.Print(err)
+			c.Status(500)
+			return
+		}
+		defer os.Remove(tmpfile.Name()) // clean up
+		if _, err := tmpfile.Write(factors); err != nil {
+			log.Print(err)
+			c.Status(500)
+			return
+		}
+		if err := tmpfile.Close(); err != nil {
+			log.Print(err)
+			c.Status(500)
+			return
+		}
+
+		// exec `pict` command
+		pictCmd := exec.Command("pict", tmpfile.Name())
+		pictOut, err := pictCmd.CombinedOutput() // get both stdin & stdout
+		if err != nil {
+			c.JSON(400, string(pictOut))
+			return
+		}
+
+		c.JSON(200, string(pictOut))
+	})
+
+	return router
 }
 
 func main() {
-	http.HandleFunc("/", handler)
-	http.ListenAndServe(":8080", nil)
+	router := SetupRouter()
+	router.Run()
 }

main_test.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+)
+
+func performRequest(r http.Handler, method, path string, body io.Reader) *httptest.ResponseRecorder {
+	req, _ := http.NewRequest(method, path, body)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+	return w
+}
+
+func TestReadiness(t *testing.T) {
+	router := SetupRouter()
+
+	response := performRequest(router, "GET", "/", nil)
+
+	assert.Equal(t, http.StatusOK, response.Code)
+	assert.Equal(t, "ok", response.Body.String())
+}
+
+func TestGeneratingCases(t *testing.T) {
+	requestBodyStruct := gin.H{
+		"factors": "SomeFactor: 1234567,2,3,4",
+	}
+	requestBody, _ := json.Marshal(requestBodyStruct)
+
+	router := SetupRouter()
+
+	response := performRequest(
+		router,
+		"POST",
+		"/generate_cases",
+		bytes.NewReader(requestBody))
+
+	assert.Equal(t, http.StatusOK, response.Code)
+	responseBody := response.Body.String()
+	assert.True(t, strings.Contains(responseBody, "SomeFactor"))
+	assert.True(t, strings.Contains(responseBody, "1234567"))
+}

scripts/push_to_gcs_as_production_build.sh

@@ -0,0 +1,6 @@
+#/bin/sh
+
+cd ~/go/src/github.com/junkboy0315/pairwise-pict-online
+docker build --target target_for_production -t pict_api:production .
+docker tag pict_api:production asia.gcr.io/pairwise-pict-online/pict_api:production
+docker push asia.gcr.io/pairwise-pict-online/pict_api:production

scripts/push_to_gcs_as_staging_build.sh

@@ -0,0 +1,6 @@
+#/bin/sh
+
+cd ~/go/src/github.com/junkboy0315/pairwise-pict-online
+docker build --target target_for_production -t pict_api:staging
+docker tag pict_api:staging asia.gcr.io/pairwise-pict-online/pict_api:staging
+docker push asia.gcr.io/pairwise-pict-online/pict_api:staging