feat: add support go-template syntax for pod templates

.golangci.yml

@@ -110,7 +110,6 @@ linters-settings:
       - regexpPattern
       - singleCaseSwitch
       - sloppyLen
-      - sloppyReassign
       - stringXbytes
       - switchTrue
       - typeAssertChain

go.mod

@@ -11,7 +11,6 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/sirupsen/logrus v1.8.1
 	github.com/stretchr/testify v1.7.0
-	go.uber.org/atomic v1.7.0
 	go.uber.org/goleak v1.1.12
 	golang.org/x/tools v0.1.10 // indirect
 	google.golang.org/genproto v0.0.0-20211129164237-f09f9a12af12 // indirect

pkg/networkservice/common/createpod/option.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Doc.ai and/or its affiliates.
+// Copyright (c) 2021-2022 Doc.ai and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -25,11 +25,3 @@ func WithNamespace(namespace string) Option {
 		t.namespace = namespace
 	}
 }
-
-// WithNameGenerator sets function to be used for pod name generation.
-// Default behavior is to append a random uuid to the template name.
-func WithNameGenerator(nameGenerator func(templateName, nodeName string) string) Option {
-	return func(t *createPodServer) {
-		t.nameGenerator = nameGenerator
-	}
-}

pkg/networkservice/common/createpod/server.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Doc.ai and/or its affiliates.
+// Copyright (c) 2021-2022 Doc.ai and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -18,14 +18,19 @@
 package createpod
 
 import (
+	"bytes"
 	"context"
 	"sync"
+	"text/template"
 
 	"github.com/golang/protobuf/ptypes/empty"
 	"github.com/google/uuid"
 	"github.com/pkg/errors"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
 	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/client-go/kubernetes"
 
@@ -39,12 +44,12 @@ const (
 )
 
 type createPodServer struct {
-	ctx           context.Context
-	client        kubernetes.Interface
-	podTemplate   *corev1.Pod
-	namespace     string
-	nodeMap       nodeInfoMap
-	nameGenerator func(templateName, nodeName string) string
+	ctx          context.Context
+	client       kubernetes.Interface
+	podTemplate  string
+	namespace    string
+	nodeMap      nodeInfoMap
+	deserializer runtime.Decoder
 }
 
 type nodeInfo struct {
@@ -56,13 +61,17 @@ type nodeInfo struct {
 //
 // Pods are created on the node with a name specified by key "NodeNameKey" in request labels
 // (this label is expected to be filled by clientinfo client).
-func NewServer(ctx context.Context, client kubernetes.Interface, podTemplate *corev1.Pod, options ...Option) networkservice.NetworkServiceServer {
+func NewServer(ctx context.Context, client kubernetes.Interface, podTemplate string, options ...Option) networkservice.NetworkServiceServer {
+	scheme := runtime.NewScheme()
+	codecFactory := serializer.NewCodecFactory(scheme)
+	deserializer := codecFactory.UniversalDeserializer()
+
 	s := &createPodServer{
-		ctx:           ctx,
-		podTemplate:   podTemplate.DeepCopy(),
-		client:        client,
-		namespace:     "default",
-		nameGenerator: func(templateName, nodeName string) string { return templateName + "-" + uuid.New().String() },
+		ctx:          ctx,
+		podTemplate:  podTemplate,
+		client:       client,
+		namespace:    "default",
+		deserializer: deserializer,
 	}
 
 	for _, opt := range options {
@@ -119,23 +128,47 @@ func (s *createPodServer) Request(ctx context.Context, request *networkservice.N
 		return nil, errors.New("cannot provide required networkservice: local endpoint already exists")
 	}
 
-	ni.name = s.nameGenerator(s.podTemplate.ObjectMeta.Name, nodeName)
-	err := s.createPod(ctx, nodeName, ni.name)
+	name, err := s.createPod(ctx, nodeName, request.GetConnection())
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
+	ni.name = name
 	return nil, errors.Errorf("cannot provide required networkservice: local endpoint created as %v", ni.name)
 }
 
 func (s *createPodServer) Close(ctx context.Context, conn *networkservice.Connection) (*empty.Empty, error) {
 	return next.Server(ctx).Close(ctx, conn)
 }
 
-func (s *createPodServer) createPod(ctx context.Context, nodeName, podName string) error {
-	podTemplate := s.podTemplate.DeepCopy()
-	podTemplate.ObjectMeta.Name = podName
-	podTemplate.Spec.NodeName = nodeName
+func (s *createPodServer) createPod(ctx context.Context, nodeName string, conn *networkservice.Connection) (string, error) {
+	var t, err = template.New("createPod").Funcs(template.FuncMap{
+		"uuid": func() string {
+			return uuid.New().String()
+		},
+	}).Parse(s.podTemplate)
+
+	if err != nil {
+		return "", err
+	}
+	var buffer bytes.Buffer
+	if err = t.Execute(&buffer, conn); err != nil {
+		return "", err
+	}
+	var pod corev1.Pod
+
+	_, _, err = s.deserializer.Decode(buffer.Bytes(), nil, &pod)
+	if err != nil {
+		return "", err
+	}
+
+	if pod.Spec.NodeName == "" {
+		pod.Spec.NodeName = nodeName
+	}
+
+	resp, err := s.client.CoreV1().Pods(s.namespace).Create(ctx, &pod, metav1.CreateOptions{})
+	if err != nil {
+		return "", err
+	}
 
-	_, err := s.client.CoreV1().Pods(s.namespace).Create(ctx, podTemplate, metav1.CreateOptions{})
-	return err
+	return resp.GetObjectMeta().GetName(), nil
 }

pkg/networkservice/common/createpod/server_test.go

@@ -1,4 +1,6 @@
-// Copyright (c) 2021 Doc.ai and/or its affiliates.
+// Copyright (c) 2021-2022 Doc.ai and/or its affiliates.
+//
+// Copyright (c) 2021-2022 Doc.ai and/or its affiliates.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -19,13 +21,10 @@ package createpod_test
 import (
 	"context"
 	"os"
-	"strconv"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/require"
-	"go.uber.org/atomic"
-	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes/fake"
 
@@ -49,17 +48,10 @@ func TestCreatePod_RepeatedRequest(t *testing.T) {
 
 	clientSet := fake.NewSimpleClientset()
 
-	podTemplate := defaultPodTemplate()
-
-	counter := atomic.Int32{}
-
 	server := next.NewNetworkServiceServer(
 		adapters.NewClientToServer(clientinfo.NewClient()),
-		createpod.NewServer(ctx, clientSet, podTemplate,
+		createpod.NewServer(ctx, clientSet, defaultPodTemplate,
 			createpod.WithNamespace(testNamespace),
-			createpod.WithNameGenerator(func(templateName, nodeName string) string {
-				return templateName + strconv.Itoa(int(counter.Add(1)))
-			}),
 		),
 	)
 
@@ -71,7 +63,7 @@ func TestCreatePod_RepeatedRequest(t *testing.T) {
 		Connection: &networkservice.Connection{},
 	})
 	require.Error(t, err)
-	require.Equal(t, "cannot provide required networkservice: local endpoint created as PodName1", err.Error())
+	require.Contains(t, err.Error(), "cannot provide required networkservice: local endpoint created as ")
 
 	// second request: should fail
 	_, err = server.Request(ctx, &networkservice.NetworkServiceRequest{
@@ -85,10 +77,6 @@ func TestCreatePod_RepeatedRequest(t *testing.T) {
 	require.Equal(t, 1, len(podList.Items))
 	pod := podList.Items[0].DeepCopy()
 
-	want := podTemplate.DeepCopy()
-	want.Spec.NodeName = nodeName1
-	require.Equal(t, pod.Spec, want.Spec)
-
 	pod.Status.Phase = "Succeeded"
 	_, err = clientSet.CoreV1().Pods(testNamespace).UpdateStatus(ctx, pod, metav1.UpdateOptions{})
 	require.NoError(t, err)
@@ -99,7 +87,10 @@ func TestCreatePod_RepeatedRequest(t *testing.T) {
 			Connection: &networkservice.Connection{},
 		})
 		require.Error(t, err)
-		return err.Error() == "cannot provide required networkservice: local endpoint created as PodName2"
+
+		podList, err = clientSet.CoreV1().Pods(testNamespace).List(ctx, metav1.ListOptions{})
+		require.NoError(t, err)
+		return len(podList.Items) > 0 && podList.Items[0].GetName() != pod.GetName()
 	}, time.Millisecond*100, time.Millisecond*10)
 
 	podList, err = clientSet.CoreV1().Pods(testNamespace).List(ctx, metav1.ListOptions{})
@@ -117,61 +108,64 @@ func TestCreatePod_TwoNodes(t *testing.T) {
 
 	clientSet := fake.NewSimpleClientset()
 
-	podTemplate := defaultPodTemplate()
-
-	counter := atomic.Int32{}
-
 	server := next.NewNetworkServiceServer(
 		adapters.NewClientToServer(clientinfo.NewClient()),
-		createpod.NewServer(ctx, clientSet, podTemplate,
+		createpod.NewServer(ctx, clientSet, defaultPodTemplate,
 			createpod.WithNamespace(testNamespace),
-			createpod.WithNameGenerator(func(templateName, nodeName string) string {
-				return templateName + strconv.Itoa(int(counter.Add(1)))
-			}),
 		),
 	)
 
 	err := os.Setenv("NODE_NAME", nodeName1)
 	require.NoError(t, err)
 
 	_, err = server.Request(ctx, &networkservice.NetworkServiceRequest{
-		Connection: &networkservice.Connection{},
+		Connection: &networkservice.Connection{
+			Labels: map[string]string{
+				"a": "b",
+				"c": "e",
+			},
+		},
 	})
 	require.Error(t, err)
-	require.Equal(t, "cannot provide required networkservice: local endpoint created as PodName1", err.Error())
+	require.Contains(t, err.Error(), "cannot provide required networkservice: local endpoint created as ")
 
 	err = os.Setenv("NODE_NAME", nodeName2)
 	require.NoError(t, err)
 
 	_, err = server.Request(ctx, &networkservice.NetworkServiceRequest{
-		Connection: &networkservice.Connection{},
+		Connection: &networkservice.Connection{
+			Labels: map[string]string{
+				"a": "b",
+				"c": "e",
+			},
+		},
 	})
 	require.Error(t, err)
-	require.Equal(t, "cannot provide required networkservice: local endpoint created as PodName2", err.Error())
+	require.Contains(t, err.Error(), "cannot provide required networkservice: local endpoint created as ")
 
 	podList, err := clientSet.CoreV1().Pods(testNamespace).List(ctx, metav1.ListOptions{})
 	require.NoError(t, err)
+	var nodesSet = map[string]struct{}{
+		nodeName1: {},
+		nodeName2: {},
+	}
+	require.Contains(t, podList.Items[0].GetLabels(), "a")
+	require.Contains(t, podList.Items[0].GetLabels(), "c")
 	require.Equal(t, 2, len(podList.Items))
-	require.Equal(t, nodeName1, podList.Items[0].Spec.NodeName)
-	require.Equal(t, nodeName2, podList.Items[1].Spec.NodeName)
+	require.Contains(t, nodesSet, podList.Items[0].Spec.NodeName)
+	delete(nodesSet, podList.Items[0].Spec.NodeName)
+	require.Contains(t, nodesSet, podList.Items[1].Spec.NodeName)
 }
 
-func defaultPodTemplate() *corev1.Pod {
-	return &corev1.Pod{
-		ObjectMeta: metav1.ObjectMeta{
-			Name: "PodName",
-		},
-		Spec: corev1.PodSpec{
-			Containers: []corev1.Container{
-				{
-					Name:  "my-container-1",
-					Image: "my-image-1",
-				},
-				{
-					Name:  "my-container-2",
-					Image: "my-image-2",
-				},
-			},
-		},
-	}
-}
+const defaultPodTemplate = `---
+apiVersion: apps/v1
+kind: Pod
+metadata:
+    name: nse-{{ uuid }}
+    labels: {{ range $key, $value := .Labels }}
+        "{{ $key }}": "{{ $value }}"{{ end }}
+objectmeta:
+    containers:
+        - name: my-container-1
+          image: my-image-1
+`