feat: Add service import command (#1065)

* feat: Add service import command

* fix: Fix e2e test

* fix: Add retry when retrieving Configuration

* fix: Reflect review feedback

* fix: Fix error message

Co-authored-by: Roland Huß <[email protected]>

* fix: Add missing mock tests

* fix: Polish unit test assertions

* fix: Mark import as experimental

* chore: Add changelog entry

* Update CHANGELOG.adoc

Co-authored-by: Roland Huß <[email protected]>

* fix: Remove deprecated flag

Co-authored-by: Roland Huß <[email protected]>

CHANGELOG.adoc

@@ -45,6 +45,10 @@
 | 🎁
 | Add WithLabel list filter to serving client lib
 | https://github.com/knative/client/pull/1054[#1054]
+
+| 🎁
+| Add `kn service import` command (experimental)
+| https://github.com/knative/client/pull/1065[#1065]
 |===
 
 ## v0.18.1 (2020-10-13)

docs/cmd/kn_service.md

@@ -32,6 +32,7 @@ kn service
 * [kn service delete](kn_service_delete.md)	 - Delete services
 * [kn service describe](kn_service_describe.md)	 - Show details of a service
 * [kn service export](kn_service_export.md)	 - Export a service and its revisions
+* [kn service import](kn_service_import.md)	 - Import a service and its revisions (experimental)
 * [kn service list](kn_service_list.md)	 - List services
 * [kn service update](kn_service_update.md)	 - Update a service
 

docs/cmd/kn_service_import.md

@@ -0,0 +1,45 @@
+## kn service import
+
+Import a service and its revisions (experimental)
+
+### Synopsis
+
+Import a service and its revisions (experimental)
+
+```
+kn service import FILENAME
+```
+
+### Examples
+
+```
+
+ # Import a service from YAML file
+ kn service import /path/to/file.yaml
+
+ # Import a service from JSON file
+ kn service import /path/to/file.json
+```
+
+### Options
+
+```
+  -h, --help               help for import
+  -n, --namespace string   Specify the namespace to operate in.
+      --no-wait            Do not wait for 'service import' operation to be completed.
+      --wait               Wait for 'service import' operation to be completed. (default true)
+      --wait-timeout int   Seconds to wait before giving up on waiting for service to be ready. (default 600)
+```
+
+### Options inherited from parent commands
+
+```
+      --config string       kn configuration file (default: ~/.config/kn/config.yaml)
+      --kubeconfig string   kubectl configuration file (default: ~/.kube/config)
+      --log-http            log http traffic
+```
+
+### SEE ALSO
+
+* [kn service](kn_service.md)	 - Manage Knative services
+

pkg/kn/commands/service/import.go

@@ -0,0 +1,143 @@
+// Copyright © 2020 The Knative Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package service
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/yaml"
+	"k8s.io/client-go/util/retry"
+
+	clientv1alpha1 "knative.dev/client/pkg/apis/client/v1alpha1"
+	"knative.dev/client/pkg/kn/commands"
+	clientservingv1 "knative.dev/client/pkg/serving/v1"
+	"knative.dev/pkg/kmeta"
+	servingv1 "knative.dev/serving/pkg/apis/serving/v1"
+)
+
+// NewServiceImportCommand returns a new command for importing a service.
+func NewServiceImportCommand(p *commands.KnParams) *cobra.Command {
+	var waitFlags commands.WaitFlags
+
+	command := &cobra.Command{
+		Use:   "import FILENAME",
+		Short: "Import a service and its revisions (experimental)",
+		Example: `
+ # Import a service from YAML file
+ kn service import /path/to/file.yaml
+
+ # Import a service from JSON file
+ kn service import /path/to/file.json`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) != 1 {
+				return errors.New("'kn service import' requires filename of import file as single argument")
+			}
+			filename := args[0]
+
+			namespace, err := p.GetNamespace(cmd)
+			if err != nil {
+				return err
+			}
+
+			client, err := p.NewServingClient(namespace)
+			if err != nil {
+				return err
+			}
+
+			return importWithOwnerRef(client, filename, cmd.OutOrStdout(), waitFlags)
+		},
+	}
+	flags := command.Flags()
+	commands.AddNamespaceFlags(flags, false)
+	waitFlags.AddConditionWaitFlags(command, commands.WaitDefaultTimeout, "import", "service", "ready")
+
+	return command
+}
+
+func importWithOwnerRef(client clientservingv1.KnServingClient, filename string, out io.Writer, waitFlags commands.WaitFlags) error {
+	var export clientv1alpha1.Export
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	decoder := yaml.NewYAMLOrJSONDecoder(file, 512)
+	err = decoder.Decode(&export)
+	if err != nil {
+		return err
+	}
+	if export.Spec.Service.Name == "" {
+		return fmt.Errorf("provided import file doesn't contain service name, please note that only kn's custom export format is supported")
+	}
+
+	serviceName := export.Spec.Service.Name
+
+	// Return error if service already exists
+	svcExists, err := serviceExists(client, serviceName)
+	if err != nil {
+		return err
+	}
+	if svcExists {
+		return fmt.Errorf("cannot import service '%s' in namespace '%s' because the service already exists",
+			serviceName, client.Namespace())
+	}
+
+	err = client.CreateService(&export.Spec.Service)
+	if err != nil {
+		return err
+	}
+
+	// Retrieve current Configuration to be use in OwnerReference
+	currentConf, err := getConfigurationWithRetry(client, serviceName)
+	if err != nil {
+		return err
+	}
+
+	// Create revision with current Configuration's OwnerReference
+	if len(export.Spec.Revisions) > 0 {
+		for _, r := range export.Spec.Revisions {
+			tmp := r.DeepCopy()
+			// OwnerRef ensures that Revisions are recognized by controller
+			tmp.OwnerReferences = []metav1.OwnerReference{*kmeta.NewControllerRef(currentConf)}
+			if err = client.CreateRevision(tmp); err != nil {
+				return err
+			}
+		}
+	}
+
+	err = waitIfRequested(client, serviceName, waitFlags, "Importing", "imported", out)
+	if err != nil {
+		return err
+	}
+	return err
+}
+
+func getConfigurationWithRetry(client clientservingv1.KnServingClient, name string) (*servingv1.Configuration, error) {
+	var conf *servingv1.Configuration
+	var err error
+	err = retry.OnError(retry.DefaultBackoff, func(err error) bool {
+		return apierrors.IsNotFound(err)
+	}, func() error {
+		conf, err = client.GetConfiguration(name)
+		return err
+	})
+	return conf, err
+}