currencyservicefake: temp replacement for currencysvc

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

kubernetes-manifests/currencyservice.yaml

@@ -0,0 +1,27 @@
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: currencyservice
+spec:
+  template:
+    metadata:
+      labels:
+        app: currencyservice
+    spec:
+      containers:
+      - name: server
+        image: currencyservice
+        ports:
+        - containerPort: 7000
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: currencyservice
+spec:
+  type: ClusterIP
+  selector:
+    app: currencyservice
+  ports:
+  - port: 7000
+    targetPort: 7000

skaffold.yaml

@@ -14,6 +14,8 @@ build:
     workspace: src/checkoutservice
   - imageName: paymentservice
     workspace: src/paymentservice
+  - imageName: currencyservice
+    workspace: src/currencyservicetemp
 deploy:
   kubectl:
     manifests:

src/currencyservicetemp/Dockerfile

@@ -0,0 +1,13 @@
+FROM golang:1.10-alpine as builder
+RUN apk add --no-cache ca-certificates git
+WORKDIR /src/microservices-demo/currencyservice
+COPY . .
+RUN go get -d ./...
+RUN go build -o /currencyservice .
+
+FROM alpine as release
+RUN apk add --no-cache \
+  ca-certificates
+COPY --from=builder /currencyservice /currencyservice
+EXPOSE 7000
+ENTRYPOINT ["/currencyservice"]

src/currencyservicetemp/main.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"os"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"google.golang.org/grpc"
+
+	pb "./genproto"
+)
+
+const (
+	listenPort = "7000"
+)
+
+type currencyServer struct {
+	currencies      []string
+	conversionRates map[[2]string]float64
+}
+
+func main() {
+	port := listenPort
+	if os.Getenv("PORT") != "" {
+		port = os.Getenv("PORT")
+	}
+
+	svc := &currencyServer{
+		currencies: []string{"USD", "EUR", "CAD"},
+		conversionRates: map[[2]string]float64{
+			{"USD", "EUR"}: 0.86,
+			{"EUR", "USD"}: 1 / 0.86,
+
+			{"USD", "CAD"}: 1.33,
+			{"CAD", "USD"}: 1 / 1.33,
+
+			{"EUR", "CAD"}: 1.54,
+			{"CAD", "EUR"}: 1 / 1.54,
+		},
+	}
+
+	lis, err := net.Listen("tcp", fmt.Sprintf(":%s", port))
+	if err != nil {
+		log.Fatal(err)
+	}
+	srv := grpc.NewServer()
+	pb.RegisterCurrencyServiceServer(srv, svc)
+	log.Printf("starting to listen on tcp: %q", lis.Addr().String())
+	log.Fatal(srv.Serve(lis))
+}
+
+func (cs *currencyServer) GetSupportedCurrencies(_ context.Context, _ *pb.Empty) (*pb.GetSupportedCurrenciesResponse, error) {
+	log.Printf("requesting supported currencies (%d)", len(cs.currencies))
+	return &pb.GetSupportedCurrenciesResponse{CurrencyCodes: cs.currencies}, nil
+}
+
+func (cs *currencyServer) Convert(_ context.Context, req *pb.CurrencyConversionRequest) (*pb.Money, error) {
+	log.Printf("requesting currency conversion [%+v] --> %s", req.From, req.ToCode)
+	conv := [2]string{req.GetFrom().GetCurrencyCode(), req.GetToCode()}
+	rate, ok := cs.conversionRates[conv]
+	if !ok {
+		return nil, status.Errorf(codes.InvalidArgument, "conversion %v not supported", conv)
+	}
+	if req.From == nil {
+		return nil, status.Errorf(codes.InvalidArgument, "no money amount provided")
+	}
+
+	amount := convert(*req.From.Amount, rate)
+	return &pb.Money{
+		CurrencyCode: req.GetToCode(),
+		Amount:       &amount}, nil
+}

src/currencyservicetemp/money.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+
+	pb "./genproto"
+)
+
+func convert(m pb.MoneyAmount, rate float64) pb.MoneyAmount {
+	d, f := m.Decimal, m.Fractional
+	lg := int(math.Max(1, math.Ceil(math.Log10(float64(f)))))
+	ff, _ := strconv.ParseFloat(fmt.Sprintf("%d.%d", d, f), 64)
+	res := ff * rate
+	resTxt := fmt.Sprintf("%."+strconv.Itoa(lg)+"f", res)
+	p := strings.Split(resTxt, ".")
+
+	ds, fs := p[0], p[1]
+	fs = strings.TrimSuffix(fs, "0")
+	if fs == "" {
+		fs = "0"
+	}
+	dn, _ := strconv.Atoi(ds)
+	fn, _ := strconv.Atoi(fs)
+
+	return pb.MoneyAmount{Decimal: uint32(dn), Fractional: uint32(fn)}
+}

src/currencyservicetemp/money_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+
+	pb "./genproto"
+)
+
+func Test_convert(t *testing.T) {
+	type args struct {
+		m    pb.MoneyAmount
+		rate float64
+	}
+	tests := []struct {
+		name string
+		args args
+		want *pb.MoneyAmount
+	}{
+		{
+			"0.33*3", args{pb.MoneyAmount{Decimal: 0, Fractional: 330}, 3}, pb.MoneyAmount{Decimal: 0, Fractional: 99},
+		},
+		{
+			"10.00*0.5", args{pb.MoneyAmount{Decimal: 10}, 0.5}, pb.MoneyAmount{Decimal: 5},
+		},
+		{
+			"10.00*1.5", args{pb.MoneyAmount{Decimal: 10}, 1.5}, pb.MoneyAmount{Decimal: 15},
+		},
+		{
+			"32.320*0.5 (trailing zero removed)", args{pb.MoneyAmount{Decimal: 32, Fractional: 32}, 0.5}, pb.MoneyAmount{Decimal: 16, Fractional: 16},
+		},
+		{
+			"33.33*(1/3) (trailing zero removed)", args{pb.MoneyAmount{Decimal: 33, Fractional: 33}, 1.0 / 3}, pb.MoneyAmount{Decimal: 11, Fractional: 11},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := convert(tt.args.m, tt.args.rate); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("convert([%v]*%f) = %v, want=[%v]", tt.args.m, tt.args.rate, got, tt.want)
+			}
+		})
+	}
+}