Merge pull request #1 from maZahaca/feature-improved-easyjson-generation

easyjson improvements

.gitignore

@@ -1 +1,2 @@
-.idea
+.idea
+*_easyjson.go

Dockerfile

@@ -2,14 +2,17 @@
 # STEP 1 build executable binary
 ############################
 # golang alpine 1.11.5
-FROM golang@sha256:8dea7186cf96e6072c23bcbac842d140fe0186758bcc215acb1745f584984857 as builder
-
-ENV GO111MODULE=on
+#FROM golang:1.11.4-alpine3.8 as builder
+FROM golang:1.11.5-alpine3.8 as builder
 
 # Install git + SSL ca certificates.
 # Git is required for fetching the dependencies.
 # Ca-certificates is required to call HTTPS endpoints.
-RUN apk update && apk add --no-cache git ca-certificates tzdata && update-ca-certificates
+RUN apk add --update --no-cache make bash git openssh-client ca-certificates build-base musl-dev curl wget tzdata \
+    && update-ca-certificates \
+    && go get -u github.com/mailru/easyjson/easyjson
+
+ENV GO111MODULE=on
 
 # Create appuser
 RUN adduser -D -g '' appuser
@@ -22,9 +25,11 @@ COPY . .
 # Using go mod.
 RUN go mod download
 
+# Generate easyjson files
+RUN go generate ./dto/*
+
 # Build the binary
 RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-w -s" -a -installsuffix cgo -o /go/bin/exchange-rates-server
-#RUN go build -o /go/bin/exchange-rates-server
 
 ############################
 # STEP 2 build a small image
@@ -43,4 +48,4 @@ COPY --from=builder /go/bin/exchange-rates-server /go/bin/exchange-rates-server
 USER appuser
 
 # Run binary.
-ENTRYPOINT ["/go/bin/exchange-rates-server", "--base", "USD", "--", "GBP", "EUR", "CAD", "RUB", "CHF", "BTC", "ETH", "ETC"]
+ENTRYPOINT ["/go/bin/exchange-rates-server", "--base", "USD", "--", "GBP", "EUR", "CAD", "RUB", "CHF", "BTC", "ETH", "ETC", "ALF", "AGS", "AMC", "APEX", "ARCH", "ARI", "BCX", "BET", "BLK"]

Makefile

@@ -0,0 +1,28 @@
+VERSION=`git rev-parse HEAD`
+BUILD=`date +%FT%T%z`
+LDFLAGS=-ldflags "-X main.Version=${VERSION} -X main.Build=${BUILD}"
+
+.PHONY: help
+help: ## - Show help message
+	@printf "\033[32m\xE2\x9c\x93 usage: make [target]\n\n\033[0m"
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
+
+.PHONY: build
+build:	## - Build the smallest and secured golang docker image based on scratch
+	@printf "\033[32m\xE2\x9c\x93 Build the smallest and secured golang docker image based on scratch\n\033[0m"
+	@docker build -f Dockerfile -t exchange-rates-server .
+
+.PHONY: build-no-cache
+build-no-cache:	## - Build the smallest and secured golang docker image based on scratch with no cache
+	@printf "\033[32m\xE2\x9c\x93 Build the smallest and secured golang docker image based on scratch\n\033[0m"
+	@docker build --no-cache -f Dockerfile -t exchange-rates-server .
+
+.PHONY: ls
+ls: ## - List 'exchange-rates-server' docker images
+	@printf "\033[32m\xE2\x9c\x93 Look at the size dude !\n\033[0m"
+	@docker image ls exchange-rates-server
+
+.PHONY: run
+run:	## - Run the smallest and secured golang docker image based on scratch
+	@printf "\033[32m\xE2\x9c\x93 Run the smallest and secured golang docker image based on scratch\n\033[0m"
+	@docker run -p 8000:8000 exchange-rates-server:latest

dto/Rates.go

@@ -1,6 +1,10 @@
+//go:generate easyjson -all
 package dto
 
-import "sync"
+import (
+	"errors"
+	"sync"
+)
 
 //easyjson:json
 type Rates struct {
@@ -21,3 +25,17 @@ func (r *Rates) Add(currency string, rate float32) {
 	r.Items[currency] = rate
 	r.mu.Unlock()
 }
+
+func (r *Rates) AddFromMap(jsonMap map[string]map[string]float32) error {
+	r.mu.Lock()
+	for currency, rate := range jsonMap {
+		var value float32
+		var ok bool
+		if value, ok = rate[r.Base]; !ok {
+			return errors.New("cannot fetch rate by base currency")
+		}
+		r.Items[currency] = 1 / value
+	}
+	r.mu.Unlock()
+	return nil
+}

main.go

@@ -2,107 +2,89 @@ package main
 
 import (
 	"bytes"
-	"encoding/json"
 	"flag"
 	"fmt"
 	"github.com/gorilla/mux"
-	"github.com/maZahaca/go-exchange-rates-service/dto"
-	"io/ioutil"
+	"github.com/maZahaca/go-exchange-rates-service/pkg"
 	"log"
 	"net/http"
+	"os"
+	"strconv"
 	"time"
 )
 
 var (
 	baseCurrency = flag.String("base", "USD", "base currency to get rates base on it")
-	urlsChunk    = 3
 )
 
 func main() {
 	flag.Parse()
 
-	var buf bytes.Buffer
-	var urls []string
-	args := flag.Args()
-	for i := 1; i <= len(args); i++ {
-		buf.WriteString(args[i-1])
-		if i%urlsChunk == 0 || i == len(args) {
-			log.Println("i=", i)
-			urls = append(
-				urls,
-				fmt.Sprintf("https://min-api.cryptocompare.com/data/pricemulti?fsyms=%s&tsyms=%s",
-					buf.String(), *baseCurrency),
-			)
-			buf.Reset()
-			continue
-		}
-		buf.WriteString(",")
+	urlsChunk, err := strconv.ParseInt(getEnv("URL_CHUNKS", "3"), 10, 8)
+	if err != nil {
+		log.Fatal(err)
+	}
+	urls, err := getUrlsFromArgs(flag.Args(), urlsChunk, *baseCurrency)
+	if err != nil {
+		log.Fatal(err)
 	}
 
-	rates := dto.NewRates(*baseCurrency)
-
-	updateRates(urls, *rates)
+	manager := pkg.NewRatesManager(*baseCurrency, urls)
+	manager.Update()
 
 	go func() {
 		for {
 			time.Sleep(10 * time.Second)
-			updateRates(urls, *rates)
+			manager.Update()
 		}
 	}()
 
 	r := mux.NewRouter()
 
 	r.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
-		rawResponse, err := rates.MarshalJSON()
+		rawResponse, err := manager.Get().MarshalJSON()
 		if err != nil {
 			log.Fatal(err)
 		}
-		writer.Write(rawResponse)
+		if _, err = writer.Write(rawResponse); err != nil {
+			log.Fatal(err)
+		}
 	})
 
+	port := getEnv("PORT", "8000")
 	srv := &http.Server{
-		Handler: r,
-		Addr:    ":8000",
-		// Good practice: enforce timeouts for servers you create!
+		Handler:      r,
+		Addr:         fmt.Sprintf(":%s", port),
 		WriteTimeout: 15 * time.Second,
 		ReadTimeout:  15 * time.Second,
 	}
 
 	log.Fatal(srv.ListenAndServe())
 }
 
-func updateRates(urls []string, rates dto.Rates) {
-	done := make(chan string, len(urls))
-
-	for i := 0; i < len(urls); i++ {
-		go fetch(urls[i], done)
-	}
-
-	for i := 0; i < len(urls); i++ {
-		res := <-done
-		jsonMap := make(map[string]map[string]float32)
-		err := json.Unmarshal([]byte(res), &jsonMap)
-		if err != nil {
-			panic(err)
-		}
-		for currency, rate := range jsonMap {
-			rates.Add(currency, 1/rate[*baseCurrency])
-		}
-		log.Println(rates)
-		log.Printf("Fetched result: %s", res)
+func getEnv(key string, defaultVal string) string {
+	val, ok := os.LookupEnv(key)
+	if !ok {
+		return defaultVal
 	}
+	return val
 }
 
-func fetch(url string, done chan string) {
-	log.Printf("fetching url: %s", url)
-	resp, err := http.Get(url)
-	defer resp.Body.Close()
-	if err != nil {
-		log.Fatalf("Cannot fetch url: %+q", err)
-	}
-	bodyBytes, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		log.Fatalf("Cannot read response: %+q", err)
+func getUrlsFromArgs(args []string, urlsChunk int64, base string) ([]string, error) {
+	var buf bytes.Buffer
+	var urls []string
+	for i := 1; i <= len(args); i++ {
+		buf.WriteString(args[i-1])
+		if i%int(urlsChunk) == 0 || i == len(args) {
+			urls = append(
+				urls,
+				fmt.Sprintf("https://min-api.cryptocompare.com/data/pricemulti?fsyms=%s&tsyms=%s",
+					buf.String(), base),
+			)
+			buf.Reset()
+			continue
+		}
+		buf.WriteString(",")
 	}
-	done <- string(bodyBytes)
+	return urls, nil
 }