feat(channel): Manage knative eventing channels (#967)

* feat(channel): Manage knative eventing channels

- Support specifying the type of channel to create using --type.
 - Default is to use messaging layer configuration for channels
- Channel type aliases via kn config and alias for InMemoryChannel
 - User can now configure channel type aliases in kn config and specify
   alias to GVK mappings for easy reference on CLI and refer with `--type` flag
 - User can also use inbuilt alias 'imc' for InMemoryChannel

* Let channel reconcile, sleep for 5 secs after creation

* Add imcv1 and imcv1beta1 aliases

* Rename imcv1 alias to imc

CHANGELOG.adoc

@@ -53,6 +53,10 @@
 | ✨
 | `kn source list` output now has client custom GVK set as `{Group: client.knative.dev, Version: v1alpha1, Kind: SourceList}`
 | https://github.com/knative/client/pull/980[#980]
+
+| 🎁
+| Manage knative eventing channels
+| https://github.com/knative/client/pull/967[#967]
 |===
 
 ## v0.16.0 (2020-07-14)

docs/cmd/kn.md

@@ -20,6 +20,7 @@ kn is the command line interface for managing Knative Serving and Eventing resou
 ### SEE ALSO
 
 * [kn broker](kn_broker.md)	 - Manage message broker
+* [kn channel](kn_channel.md)	 - Manage event channels
 * [kn completion](kn_completion.md)	 - Output shell completion code
 * [kn options](kn_options.md)	 - Print the list of flags inherited by all commands
 * [kn plugin](kn_plugin.md)	 - Manage kn plugins

docs/cmd/kn_channel.md

@@ -0,0 +1,34 @@
+## kn channel
+
+Manage event channels
+
+### Synopsis
+
+Manage event channels
+
+```
+kn channel COMMAND
+```
+
+### Options
+
+```
+  -h, --help   help for channel
+```
+
+### 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](kn.md)	 - kn manages Knative Serving and Eventing resources
+* [kn channel create](kn_channel_create.md)	 - Create an event channel
+* [kn channel delete](kn_channel_delete.md)	 - Delete a channel
+* [kn channel describe](kn_channel_describe.md)	 - Show details of a channel
+* [kn channel list](kn_channel_list.md)	 - List channels
+

docs/cmd/kn_channel_create.md

@@ -0,0 +1,48 @@
+## kn channel create
+
+Create an event channel
+
+### Synopsis
+
+Create an event channel
+
+```
+kn channel create NAME
+```
+
+### Examples
+
+```
+
+  # Create a channel 'pipe' with default setting for channel configuration
+  kn channel create pipe
+
+  # Create a channel 'imc1' of type InMemoryChannel using inbuilt alias 'imc'
+  kn channel create imc1 --type imc
+  # same as above without using inbuilt alias but providing explicit GVK
+  kn channel create imc1 --type messaging.knative.dev:v1beta1:InMemoryChannel
+
+  # Create a channel 'k1' of type KafkaChannel
+  kn channel create k1 --type messaging.knative.dev:v1alpha1:KafkaChannel
+```
+
+### Options
+
+```
+  -h, --help               help for create
+  -n, --namespace string   Specify the namespace to operate in.
+      --type string        Override channel type to create, in the format '--type Group:Version:Kind'. If flag is not specified, it uses default messaging layer settings for channel type, cluster wide or specific namespace. You can configure aliases for channel types in kn config and refer the aliases with this flag. You can also refer inbuilt channel type InMemoryChannel using an alias 'imc' like '--type imc'. Examples: '--type messaging.knative.dev:v1alpha1:KafkaChannel' for specifying explicit Group:Version:Kind.
+```
+
+### 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 channel](kn_channel.md)	 - Manage event channels
+

docs/cmd/kn_channel_delete.md

@@ -0,0 +1,39 @@
+## kn channel delete
+
+Delete a channel
+
+### Synopsis
+
+Delete a channel
+
+```
+kn channel delete NAME
+```
+
+### Examples
+
+```
+
+  # Delete a channel 'pipe'
+  kn channel delete pipe
+```
+
+### Options
+
+```
+  -h, --help               help for delete
+  -n, --namespace string   Specify the namespace to operate in.
+```
+
+### 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 channel](kn_channel.md)	 - Manage event channels
+

docs/cmd/kn_channel_describe.md

@@ -0,0 +1,43 @@
+## kn channel describe
+
+Show details of a channel
+
+### Synopsis
+
+Show details of a channel
+
+```
+kn channel describe NAME
+```
+
+### Examples
+
+```
+
+  # Describe a channel 'pipe'
+  kn channel describe pipe
+```
+
+### Options
+
+```
+      --allow-missing-template-keys   If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats. (default true)
+  -h, --help                          help for describe
+  -n, --namespace string              Specify the namespace to operate in.
+  -o, --output string                 Output format. One of: json|yaml|name|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-file.
+      --template string               Template string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].
+  -v, --verbose                       More output.
+```
+
+### 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 channel](kn_channel.md)	 - Manage event channels
+

docs/cmd/kn_channel_list.md

@@ -0,0 +1,47 @@
+## kn channel list
+
+List channels
+
+### Synopsis
+
+List channels
+
+```
+kn channel list
+```
+
+### Examples
+
+```
+
+  # List all channels
+  kn channel list
+
+  # List channels in YAML format
+  kn channel ping list -o yaml
+```
+
+### Options
+
+```
+  -A, --all-namespaces                If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even if specified with --namespace.
+      --allow-missing-template-keys   If true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats. (default true)
+  -h, --help                          help for list
+  -n, --namespace string              Specify the namespace to operate in.
+      --no-headers                    When using the default output format, don't print headers (default: print headers).
+  -o, --output string                 Output format. One of: json|yaml|name|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-file.
+      --template string               Template string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].
+```
+
+### 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 channel](kn_channel.md)	 - Manage event channels
+

lib/test/channel.go

@@ -0,0 +1,55 @@
+// 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 im
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package test
+
+import (
+	"time"
+
+	"gotest.tools/assert"
+
+	"knative.dev/client/pkg/util"
+)
+
+func ChannelCreate(r *KnRunResultCollector, cname string, args ...string) {
+	cmd := []string{"channel", "create", cname}
+	cmd = append(cmd, args...)
+	out := r.KnTest().Kn().Run(cmd...)
+	r.AssertNoError(out)
+	assert.Check(r.T(), util.ContainsAllIgnoreCase(out.Stdout, "channel", cname, "created"))
+	// let channel reconcile TODO: fix the wait for channel to become ready
+	time.Sleep(5 * time.Second)
+}
+
+func ChannelList(r *KnRunResultCollector, args ...string) string {
+	cmd := []string{"channel", "list"}
+	cmd = append(cmd, args...)
+	out := r.KnTest().Kn().Run(cmd...)
+	r.AssertNoError(out)
+	return out.Stdout
+}
+
+func ChannelDescribe(r *KnRunResultCollector, cname string, args ...string) string {
+	cmd := []string{"channel", "describe", cname}
+	cmd = append(cmd, args...)
+	out := r.KnTest().Kn().Run(cmd...)
+	r.AssertNoError(out)
+	return out.Stdout
+}
+
+func ChannelDelete(r *KnRunResultCollector, cname string) {
+	out := r.KnTest().Kn().Run("channel", "delete", cname)
+	r.AssertNoError(out)
+	assert.Check(r.T(), util.ContainsAllIgnoreCase(out.Stdout, "channel", cname, "deleted"))
+}

pkg/errors/factory.go

@@ -42,6 +42,10 @@ func isEmptyConfigError(err error) bool {
 //Retrieves a custom error struct based on the original error APIStatus struct
 //Returns the original error struct in case it can't identify the kind of APIStatus error
 func GetError(err error) error {
+	if err == nil {
+		return nil
+	}
+
 	switch {
 	case isEmptyConfigError(err):
 		return newNoKubeConfig(err.Error())

pkg/errors/factory_test.go

@@ -161,3 +161,7 @@ func TestIsForbiddenError(t *testing.T) {
 		})
 	}
 }
+
+func TestNilError(t *testing.T) {
+	assert.NilError(t, GetError(nil), nil)
+}

pkg/kn/commands/channel/channel.go

@@ -0,0 +1,67 @@
+// 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 channel
+
+import (
+	"github.com/spf13/cobra"
+
+	"k8s.io/client-go/tools/clientcmd"
+	clientv1beta1 "knative.dev/eventing/pkg/client/clientset/versioned/typed/messaging/v1beta1"
+
+	"knative.dev/client/pkg/kn/commands"
+	messagingv1beta1 "knative.dev/client/pkg/messaging/v1beta1"
+)
+
+// NewChannelCommand to manage event channels
+func NewChannelCommand(p *commands.KnParams) *cobra.Command {
+	channelCmd := &cobra.Command{
+		Use:   "channel COMMAND",
+		Short: "Manage event channels",
+	}
+	channelCmd.AddCommand(NewChannelCreateCommand(p))
+	channelCmd.AddCommand(NewChannelListCommand(p))
+	channelCmd.AddCommand(NewChannelDeleteCommand(p))
+	channelCmd.AddCommand(NewChannelDescribeCommand(p))
+	return channelCmd
+}
+
+var channelClientFactory func(config clientcmd.ClientConfig, namespace string) (messagingv1beta1.KnChannelsClient, error)
+
+func newChannelClient(p *commands.KnParams, cmd *cobra.Command) (messagingv1beta1.KnChannelsClient, error) {
+	namespace, err := p.GetNamespace(cmd)
+	if err != nil {
+		return nil, err
+	}
+
+	if channelClientFactory != nil {
+		config, err := p.GetClientConfig()
+		if err != nil {
+			return nil, err
+		}
+		return channelClientFactory(config, namespace)
+	}
+
+	clientConfig, err := p.RestConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	client, err := clientv1beta1.NewForConfig(clientConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	return messagingv1beta1.NewKnMessagingClient(client, namespace).ChannelsClient(), nil
+}