initial commit

Author: jsreed

Makefile

@@ -0,0 +1,8 @@
+gqlgen:
+	go run github.com/99designs/gqlgen -v -c ./api/gateway/gqlgen.yml
+
+protobuf:
+	protoc --go_out=plugins=grpc:. api/echo/echo.proto
+
+dev:
+	skaffold dev

README.md

@@ -0,0 +1,5 @@
+## Weekend project playing around with golang and kubernetes.
+
+Assumes you have a  kubernetes cluster with istio setup and an 'echo' namespace.
+
+Run 'skaffold dev' to start developing.

api/echo/echo.pb.go

@@ -0,0 +1,13 @@
+syntax = "proto3";
+package api;
+
+message EchoRequest {
+    string payload = 1;
+}
+
+message EchoResponse {
+    string requestPayload = 1;
+}
+service Echo {
+    rpc echo(EchoRequest) returns (EchoResponse) {}
+}

api/echo/echo.proto

@@ -0,0 +1,18 @@
+schema:
+  - "api/gateway/**/*.graphql"
+
+# Let gqlgen know where to put the generated server
+exec:
+  filename: internal/gateway/generated/graphql.go
+  package: generated
+
+autobind:
+  - github.com/jsreed/echo/model
+
+# Let gqlgen know where to put the generated models (if any)
+model:
+  filename: model/generated.go
+  package: model
+
+# Optional, turns on binding to field names by tag provided
+struct_tag: json

api/gateway/gqlgen.yml

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+type Query {
+    Echo(payload: String!): String!
+}

api/gateway/schema.graphql

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	api "github.com/jsreed/echo/api/echo"
+	"github.com/jsreed/echo/internal/echo/impl"
+	"github.com/spf13/viper"
+	"google.golang.org/grpc"
+	"log"
+	"net"
+)
+
+func init() {
+	viper.SetDefault("port", "9000")
+}
+
+func main() {
+	log.Print("Starting echo")
+	lis, err := net.Listen("tcp", fmt.Sprintf(":%s", viper.Get("port")))
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+
+	echoImpl := &impl.Echo{}
+
+	grpcServer := grpc.NewServer()
+
+	api.RegisterEchoServer(grpcServer, echoImpl)
+
+	if err := grpcServer.Serve(lis); err != nil {
+		log.Fatalf("failed to serve: %s", err)
+	}
+}

cmd/echo/main.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"fmt"
+	"github.com/99designs/gqlgen/handler"
+	api "github.com/jsreed/echo/api/echo"
+	"github.com/jsreed/echo/internal/gateway/generated"
+	"github.com/jsreed/echo/internal/gateway/resolvers"
+	"github.com/spf13/viper"
+	"google.golang.org/grpc"
+	"log"
+	"net/http"
+)
+
+func init() {
+	viper.SetDefault("echo_url", "echo:9000")
+	viper.SetDefault("port", "4200")
+}
+
+func main() {
+	log.Print("Starting gateway")
+
+	conn, err := grpc.Dial(viper.GetString("echo_url"), grpc.WithInsecure())
+	if err != nil {
+		log.Fatalf("Dial Failed: %v", err)
+	}
+
+	echoClient := api.NewEchoClient(conn)
+
+	http.Handle("/",handler.Playground("echo playground", "/query"))
+	http.Handle("/query", handler.GraphQL(
+		generated.NewExecutableSchema(
+			generated.Config{
+				Resolvers: &resolvers.Resolver{
+					EchoCli: echoClient,
+				},
+			},
+		),
+	))
+	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", viper.Get("port")), nil))
+}

cmd/gateway/main.go

@@ -0,0 +1,14 @@
+FROM golang:1.13
+
+WORKDIR /go/src/github.com/jsreed/echo
+
+COPY go.mod .
+COPY go.sum .
+
+RUN go mod download
+
+COPY . .
+
+EXPOSE 9000
+
+CMD go run /go/src/github.com/jsreed/echo/cmd/echo

deployment/echo/Dockerfile.dev

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: echo-deployment
+  labels:
+    app: echo
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: echo
+  template:
+    metadata:
+      labels:
+        app: echo
+    spec:
+      containers:
+        - name: echo
+          image: echo/echo:latest
+          ports:
+            - containerPort: 9000

deployment/echo/k8s/deployment.yml

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: echo
+  labels:
+    app: echo
+    service: echo
+spec:
+  ports:
+    - port: 9000
+      protocol: TCP
+      name: grpc
+  selector:
+    app: echo

deployment/echo/k8s/service.yml

@@ -0,0 +1,14 @@
+FROM golang:1.13
+
+WORKDIR /go/src/github.com/jsreed/echo
+
+COPY go.mod .
+COPY go.sum .
+
+RUN go mod download
+
+COPY . .
+
+EXPOSE 4200
+
+CMD go run /go/src/github.com/jsreed/echo/cmd/gateway

deployment/gateway/Dockerfile.dev

@@ -0,0 +1,21 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: gateway-deployment
+  labels:
+    app: gateway
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: gateway
+  template:
+    metadata:
+      labels:
+        app: gateway
+    spec:
+      containers:
+        - name: gateway
+          image: echo/gateway:latest
+          ports:
+            - containerPort: 4200

deployment/gateway/k8s/deployment.yml

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+apiVersion: networking.istio.io/v1alpha3
+kind: Gateway
+metadata:
+  name: echo-gateway
+spec:
+  selector:
+    istio: ingressgateway
+  servers:
+    - port:
+        number: 4200
+        name: http
+        protocol: HTTP
+      hosts:
+        - "*"

deployment/gateway/k8s/istio.gateway.yml

@@ -0,0 +1,13 @@
+apiVersion: networking.istio.io/v1alpha3
+kind: VirtualService
+metadata:
+  name: echo-virtualservice
+spec:
+  gateways:
+    - echo-gateway
+  hosts:
+    - "*"
+  http:
+    - route:
+        - destination:
+            host: gateway.default.svc.cluster.local

deployment/gateway/k8s/istio.virtual_service.yml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: gateway-service
+  labels:
+    app: gateway
+spec:
+  ports:
+    - port: 4200
+      name: http
+  selector:
+    app: gateway

deployment/gateway/k8s/service.yml

@@ -0,0 +1,13 @@
+module github.com/jsreed/echo
+
+go 1.13
+
+require (
+	github.com/99designs/gqlgen v0.10.2
+	github.com/golang/protobuf v1.3.1
+	github.com/spf13/viper v1.5.0
+	github.com/vektah/gqlparser v1.2.0
+	go.uber.org/zap v1.13.0
+	golang.org/x/net v0.0.0-20190620200207-3b0461eec859
+	google.golang.org/grpc v1.21.0
+)

go.mod

@@ -0,0 +1,17 @@
+package impl
+
+import (
+	"github.com/jsreed/echo/api/echo"
+	"golang.org/x/net/context"
+	"log"
+)
+
+type Echo struct {}
+
+func (e Echo) Echo(ctx context.Context, request *api.EchoRequest) (response *api.EchoResponse, err error) {
+	log.Print("echoing!!")
+	response = &api.EchoResponse{
+		RequestPayload: request.Payload,
+	}
+	return
+}

go.sum

@@ -0,0 +1,27 @@
+package resolvers
+
+import (
+	"context"
+	api "github.com/jsreed/echo/api/echo"
+	"log"
+)
+
+type queryResolver struct{ *Resolver }
+
+func (q queryResolver) Echo(ctx context.Context, payload string) (returnPayload string, err error) {
+	log.Print("handling echo query")
+
+	echoResponse, err := q.EchoCli.Echo(ctx, &api.EchoRequest{
+		Payload: payload,
+	})
+	if err != nil {
+		log.Print(err)
+	}
+	if echoResponse == nil {
+		return "nil echoResponse", nil
+	}
+
+	return echoResponse.RequestPayload, err
+}
+
+

internal/echo/impl/echo.go

@@ -0,0 +1,14 @@
+package resolvers
+
+import (
+	api "github.com/jsreed/echo/api/echo"
+	"github.com/jsreed/echo/internal/gateway/generated"
+)
+
+type Resolver struct{
+	EchoCli api.EchoClient
+}
+
+func (r *Resolver) Query() generated.QueryResolver {
+	return &queryResolver{r}
+}

internal/gateway/generated/graphql.go

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+apiVersion: skaffold/v1
+kind: Config
+metadata:
+  name:  "echo"
+build:
+  artifacts:
+    - image: echo/gateway
+      context: .
+      docker:
+        dockerfile: ./deployment/gateway/Dockerfile.dev
+    - image: echo/echo
+      context: .
+      docker:
+        dockerfile: ./deployment/echo/Dockerfile.dev
+deploy:
+  kubectl:
+    manifests:
+      - ./deployment/gateway/k8s/*.yml
+      - ./deployment/echo/k8s/*.yml
+    flags:
+       global: ["--namespace=echo"]