client/pkg/commands/channel/describe.go

122 lines
3.4 KiB
Go

// 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 (
"errors"
"fmt"
"strings"
"github.com/spf13/cobra"
"k8s.io/cli-runtime/pkg/genericclioptions"
messagingv1 "knative.dev/eventing/pkg/apis/messaging/v1"
"knative.dev/client/pkg/commands"
knerrors "knative.dev/client/pkg/errors"
"knative.dev/client/pkg/printers"
)
var describeExample = `
# Describe a channel 'pipe'
kn channel describe pipe
# Print only channel URL
kn channel describe pipe -o url`
// NewChannelDescribeCommand returns a new command for describe a channel object
func NewChannelDescribeCommand(p *commands.KnParams) *cobra.Command {
// For machine readable output
machineReadablePrintFlags := genericclioptions.NewPrintFlags("")
cmd := &cobra.Command{
Use: "describe NAME",
Short: "Show details of a channel",
Example: describeExample,
ValidArgsFunction: commands.ResourceNameCompletionFunc(p),
RunE: func(cmd *cobra.Command, args []string) error {
if len(args) != 1 {
return errors.New("'kn channel describe' requires the channel name given as single argument")
}
name := args[0]
client, err := newChannelClient(p, cmd)
if err != nil {
return err
}
channel, err := client.GetChannel(cmd.Context(), name)
if err != nil {
return knerrors.GetError(err)
}
out := cmd.OutOrStdout()
if machineReadablePrintFlags.OutputFlagSpecified() {
if strings.ToLower(*machineReadablePrintFlags.OutputFormat) == "url" {
fmt.Fprintf(out, "%s\n", extractURL(channel))
return nil
}
printer, err := machineReadablePrintFlags.ToPrinter()
if err != nil {
return err
}
return printer.PrintObj(channel, out)
}
dw := printers.NewPrefixWriter(out)
printDetails, err := cmd.Flags().GetBool("verbose")
if err != nil {
return err
}
writeChannel(dw, channel, printDetails)
dw.WriteLine()
if err := dw.Flush(); err != nil {
return err
}
// Condition info
commands.WriteConditions(dw, channel.Status.Conditions, printDetails)
if err := dw.Flush(); err != nil {
return err
}
return nil
},
}
flags := cmd.Flags()
commands.AddNamespaceFlags(flags, false)
flags.BoolP("verbose", "v", false, "More output.")
machineReadablePrintFlags.AddFlags(cmd)
cmd.Flag("output").Usage = fmt.Sprintf("Output format. One of: %s.", strings.Join(append(machineReadablePrintFlags.AllowedFormats(), "url"), "|"))
return cmd
}
func writeChannel(dw printers.PrefixWriter, channel *messagingv1.Channel, printDetails bool) {
commands.WriteMetadata(dw, &channel.ObjectMeta, printDetails)
ctype := fmt.Sprintf("%s (%s)", channel.Spec.ChannelTemplate.Kind, channel.Spec.ChannelTemplate.APIVersion)
dw.WriteAttribute("Type", ctype)
if channel.Status.Address != nil {
dw.WriteAttribute("URL", extractURL(channel))
}
}
func extractURL(channel *messagingv1.Channel) string {
return channel.Status.Address.URL.String()
}