feat: Support multiple renderer render in skaffold dev and skaffold r…

…un (#7697)

* feat: allow multiple mixed in renderers

* add integration tests and fix examples

* fix example

* fix integration tests

* fix lint

* fix lint

integration/examples/multiple-renderers/backend/Chart.yaml

@@ -0,0 +1,4 @@
+apiVersion: v1
+description: back end for guestbook
+name: backend
+version: 0.1.0

integration/examples/multiple-renderers/backend/src/Dockerfile

@@ -0,0 +1,29 @@
+# Use base golang image from Docker Hub
+FROM golang:1.17 as build
+
+WORKDIR /app
+
+# Copy the go.mod and go.sum, download the dependencies
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy rest of the application source code
+COPY . ./
+
+# Compile the application to /app/backend.
+# Skaffold passes in debug-oriented compiler flags
+ARG SKAFFOLD_GO_GCFLAGS
+RUN echo "Go gcflags: ${SKAFFOLD_GO_GCFLAGS}"
+RUN go build -gcflags="${SKAFFOLD_GO_GCFLAGS}" -mod=readonly -v -o /app/backend .
+
+# Now create separate deployment image
+FROM gcr.io/distroless/base
+
+# Definition of this variable is used by 'skaffold debug' to identify a golang binary.
+# Default behavior - a failure prints a stack trace for the current goroutine.
+# See https://golang.org/pkg/runtime/
+ENV GOTRACEBACK=single
+
+WORKDIR /app
+COPY --from=build /app/backend /app/backend
+ENTRYPOINT ["/app/backend"]

integration/examples/multiple-renderers/backend/src/database.go

@@ -0,0 +1,10 @@
+package main
+
+import (
+	"context"
+)
+
+type database interface {
+	entries(context.Context) ([]guestbookEntry, error)
+	addEntry(context.Context, guestbookEntry) error
+}

integration/examples/multiple-renderers/backend/src/go.mod

@@ -0,0 +1,9 @@
+module backend
+
+go 1.12
+
+require (
+	github.com/DataDog/zstd v1.4.4 // indirect
+	github.com/xdg/stringprep v1.0.0 // indirect
+	go.mongodb.org/mongo-driver v1.8.4
+)

integration/examples/multiple-renderers/backend/src/main.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+	"go.mongodb.org/mongo-driver/mongo/readpref"
+)
+
+// guestbookEntry represents the message object returned in the API.
+type guestbookEntry struct {
+	Author  string    `json:"author" bson:"author"`
+	Message string    `json:"message" bson:"message"`
+	Date    time.Time `json:"date" bson:"date"`
+}
+
+type guestbookServer struct {
+	db database
+}
+
+// main starts a server listening on $PORT responding to requests "GET
+// /messages" and "POST /messages" with a JSON API.
+func main() {
+	ctx := context.Background()
+
+	// PORT environment variable is set in guestbook-backend.deployment.yaml.
+	port := os.Getenv("PORT")
+	if port == "" {
+		log.Fatal("PORT environment variable not specified")
+	}
+	// GUESTBOOK_DB_ADDR environment variable is set in guestbook-backend.deployment.yaml.
+	dbAddr := os.Getenv("GUESTBOOK_DB_ADDR")
+	if dbAddr == "" {
+		log.Fatal("GUESTBOOK_DB_ADDR environment variable not specified")
+	}
+
+	mongoURI := "mongodb://" + dbAddr
+	connCtx, cancel := context.WithTimeout(ctx, time.Second*30)
+	defer cancel()
+	dbConn, err := mongo.Connect(connCtx, options.Client().ApplyURI(mongoURI))
+	if err != nil {
+		log.Fatalf("failed to initialize connection to mongodb: %+v", err)
+	}
+	if err := dbConn.Ping(connCtx, readpref.Primary()); err != nil {
+		log.Fatalf("ping to mongodb failed: %+v", err)
+	}
+
+	gs := &guestbookServer{
+		db: &mongodb{
+			conn: dbConn,
+		},
+	}
+
+	log.Printf("backend server listening on port %s", port)
+	http.Handle("/messages", gs)
+	if err := http.ListenAndServe(":"+port, nil); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func (s *guestbookServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	log.Printf("received request: method=%s path=%s", r.Method, r.URL.Path)
+	if r.Method == http.MethodGet {
+		s.getMessagesHandler(w, r)
+	} else if r.Method == http.MethodPost {
+		s.postMessageHandler(w, r)
+	} else {
+		http.Error(w, fmt.Sprintf("unsupported method %s", r.Method), http.StatusMethodNotAllowed)
+	}
+}
+
+func (s *guestbookServer) getMessagesHandler(w http.ResponseWriter, r *http.Request) {
+	entries, err := s.db.entries(r.Context())
+	if err != nil {
+		http.Error(w, fmt.Sprintf("failed to read entries: %+v", err), http.StatusInternalServerError)
+		// TODO return JSON error
+		return
+	}
+	if err := json.NewEncoder(w).Encode(entries); err != nil {
+		log.Printf("WARNING: failed to encode json into response: %+v", err)
+	} else {
+		log.Printf("%d entries returned", len(entries))
+	}
+}
+
+func (s *guestbookServer) postMessageHandler(w http.ResponseWriter, r *http.Request) {
+	defer r.Body.Close()
+
+	var v guestbookEntry
+	if err := json.NewDecoder(r.Body).Decode(&v); err != nil {
+		http.Error(w, fmt.Sprintf("failed to decode request body into json: %+v", err), http.StatusBadRequest)
+		return
+	}
+	if v.Author == "" {
+		http.Error(w, "empty 'author' value", http.StatusBadRequest)
+		return
+	}
+	if v.Message == "" {
+		http.Error(w, "empty 'message' value", http.StatusBadRequest)
+		return
+	}
+
+	v.Date = time.Now()
+
+	if err := s.db.addEntry(r.Context(), v); err != nil {
+		http.Error(w, fmt.Sprintf("failed to save entry: %+v", err), http.StatusInternalServerError)
+		return
+	}
+	log.Printf("entry saved: author=%q message=%q", v.Author, v.Message)
+}

integration/examples/multiple-renderers/backend/src/mongodb.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+type mongodb struct {
+	conn *mongo.Client
+}
+
+func (m *mongodb) entries(ctx context.Context) ([]guestbookEntry, error) {
+	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+
+	col := m.conn.Database("guestbook").Collection("entries")
+	cur, err := col.Find(ctx, bson.D{}, &options.FindOptions{
+		Sort: map[string]interface{}{"_id": -1},
+	})
+	if err != nil {
+		return nil, fmt.Errorf("mongodb.Find failed: %+v", err)
+	}
+	defer cur.Close(ctx)
+
+	var out []guestbookEntry
+	for cur.Next(ctx) {
+		var v guestbookEntry
+		if err := cur.Decode(&v); err != nil {
+			return nil, fmt.Errorf("decoding mongodb record failed: %+v", err)
+		}
+		out = append(out, v)
+	}
+	if err := cur.Err(); err != nil {
+		return nil, fmt.Errorf("failed to iterate on mongodb cursor: %+v", err)
+	}
+	return out, nil
+}
+
+func (m *mongodb) addEntry(ctx context.Context, e guestbookEntry) error {
+	ctx, cancel := context.WithTimeout(ctx, time.Second*3)
+	defer cancel()
+
+	col := m.conn.Database("guestbook").Collection("entries")
+	if _, err := col.InsertOne(ctx, e); err != nil {
+		return fmt.Errorf("mongodb.InsertOne failed: %+v", err)
+	}
+	return nil
+}

integration/examples/multiple-renderers/backend/templates/deployment.yaml

@@ -0,0 +1,29 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: {{ .Chart.Name }}
+  labels:
+    app: {{ .Chart.Name }}
+spec:
+  selector:
+    matchLabels:
+      app: {{ .Chart.Name }}
+  replicas: {{ .Values.replicaCount }}
+  template:
+    metadata:
+      labels:
+        app: {{ .Chart.Name }}
+    spec:
+      containers:
+      - name: {{ .Chart.Name }}
+        image: {{ .Values.image }}
+        ports:
+        - name: http-server
+          containerPort: 8081
+        - name: debug
+          containerPort: 3000
+        env:
+        - name: PORT
+          value: "8081"
+        - name: GUESTBOOK_DB_ADDR
+          value: go-guestbook-mongodb:27017

integration/examples/multiple-renderers/backend/templates/guestbook-mongodb.deployment.yaml

@@ -0,0 +1,29 @@
+################################################################################
+# WARNING: This MongoDB deployment is not suitable for production as the data is
+# not persistently stored and will go away every time the Pod restarts. Consider
+# using a Helm chart that provisions a StatefulSet instead of Deployment.
+################################################################################
+kind: Deployment
+apiVersion: apps/v1
+metadata:
+  name: go-guestbook-mongodb
+  labels:
+    app: guestbook
+    tier: db
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: guestbook
+      tier: db
+  template:
+    metadata:
+      labels:
+        app: guestbook
+        tier: db
+    spec:
+      containers:
+        - name: mongo
+          image: mongo:4
+          ports:
+            - containerPort: 27017

integration/examples/multiple-renderers/backend/templates/guestbook-mongodb.service.yaml

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: go-guestbook-mongodb
+  labels:
+    app: guestbook
+    tier: db
+spec:
+  ports:
+    - port: 27017
+      targetPort: 27017
+  selector:
+    app: guestbook
+    tier: db

integration/examples/multiple-renderers/backend/templates/service.yaml

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ .Chart.Name }}
+  labels:
+    app: {{ .Chart.Name }}
+spec:
+  type: ClusterIP
+  selector:
+    app: {{ .Chart.Name }}
+  ports:
+  - port: 8081
+    targetPort: http-server

integration/examples/multiple-renderers/backend/val.yaml

@@ -0,0 +1,2 @@
+# This is another YAML-formatted file.
+image: go-guestbook-backend

integration/examples/multiple-renderers/backend/values.yaml

@@ -0,0 +1,3 @@
+# This is a YAML-formatted file.
+# Declare variables to be passed into your templates.
+replicaCount: 1

integration/examples/multiple-renderers/frontend/k8s/deployment.yaml

@@ -0,0 +1,29 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: frontend
+  labels:
+    app: frontend
+spec:
+  selector:
+    matchLabels:
+      app: frontend
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: frontend
+    spec:
+      containers:
+      - name: frontend
+        image: go-guestbook-frontend
+        ports:
+        - name: http-server
+          containerPort: 8080
+        - name: debug
+          containerPort: 3000
+        env:
+        - name: PORT
+          value: "8080"
+        - name: GUESTBOOK_API_ADDR
+          value: localhost:27017

integration/examples/multiple-renderers/frontend/k8s/service.yaml

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: frontend
+  labels:
+    app: frontend
+spec:
+  type: ClusterIP
+  selector:
+    app: frontend
+  ports:
+  - port: 8080
+    targetPort: http-server