karmada/pkg/karmadactl/logs/logs.go

/*
Copyright 2022 The Karmada 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 logs

import (
	"fmt"

	"github.com/spf13/cobra"
	"k8s.io/cli-runtime/pkg/genericiooptions"
	kubectllogs "k8s.io/kubectl/pkg/cmd/logs"
	cmdutil "k8s.io/kubectl/pkg/cmd/util"
	"k8s.io/kubectl/pkg/util/templates"

	"github.com/karmada-io/karmada/pkg/karmadactl/options"
	"github.com/karmada-io/karmada/pkg/karmadactl/util"
	utilcomp "github.com/karmada-io/karmada/pkg/karmadactl/util/completion"
)

const (
	logsUsageStr = "logs [-f] [-p] (POD | TYPE/NAME) [-c CONTAINER] (-C CLUSTER)"
)

var (
	logsLong = templates.LongDesc(`
		Print the logs for a container in a pod in a member cluster or specified resource. If the pod has
		only one container, the container name is optional.`)

	logsUsageErrStr = fmt.Sprintf("expected '%s'.\nPOD or TYPE/NAME is a required argument for the logs command", logsUsageStr)

	logsExample = templates.Examples(`
		# Return snapshot logs from pod nginx with only one container in cluster(member1)
		%[1]s logs nginx -C=member1

		# Return snapshot logs from pod nginx with multi containers in cluster(member1)
		%[1]s logs nginx --all-containers=true -C=member1

		# Return snapshot logs from all containers in pods defined by label app=nginx in cluster(member1)
		%[1]s logs -l app=nginx --all-containers=true -C=member1

		# Return snapshot of previous terminated ruby container logs from pod web-1 in cluster(member1)
		%[1]s logs -p -c ruby web-1 -C=member1

		# Begin streaming the logs of the ruby container in pod web-1 in cluster(member1)
		%[1]s logs -f -c ruby web-1 -C=member1

		# Begin streaming the logs from all containers in pods defined by label app=nginx in cluster(member1)
		%[1]s logs -f -l app=nginx --all-containers=true -C=member1

		# Display only the most recent 20 lines of output in pod nginx in cluster(member1)
		%[1]s logs --tail=20 nginx -C=member1

		# Show all logs from pod nginx written in the last hour in cluster(member1)
		%[1]s logs --since=1h nginx -C=member1`)
)

// NewCmdLogs new logs command.
func NewCmdLogs(f util.Factory, parentCommand string, streams genericiooptions.IOStreams) *cobra.Command {
	o := &CommandLogsOptions{
		KubectlLogsOptions: kubectllogs.NewLogsOptions(streams, false),
	}

	cmd := &cobra.Command{
		Use:                   logsUsageStr,
		Short:                 "Print the logs for a container in a pod in a cluster",
		Long:                  logsLong,
		SilenceUsage:          true,
		DisableFlagsInUseLine: true,
		Example:               fmt.Sprintf(logsExample, parentCommand),
		ValidArgsFunction:     utilcomp.PodResourceNameAndContainerCompletionFunc(f),
		RunE: func(cmd *cobra.Command, args []string) error {
			if err := o.Complete(cmd, args, f); err != nil {
				return err
			}
			if err := o.Validate(); err != nil {
				return err
			}
			if err := o.Run(); err != nil {
				return err
			}
			return nil
		},
		Annotations: map[string]string{
			util.TagCommandGroup: util.GroupClusterTroubleshootingAndDebugging,
		},
	}

	flags := cmd.Flags()
	options.AddKubeConfigFlags(flags)
	options.AddNamespaceFlag(flags)
	flags.StringVarP(&o.Cluster, "cluster", "C", "", "Specify a member cluster")
	o.KubectlLogsOptions.AddFlags(cmd)

	utilcomp.RegisterCompletionFuncForKarmadaContextFlag(cmd)
	utilcomp.RegisterCompletionFuncForNamespaceFlag(cmd, f)
	utilcomp.RegisterCompletionFuncForClusterFlag(cmd)
	return cmd
}

// CommandLogsOptions contains the input to the logs command.
type CommandLogsOptions struct {
	// flags specific to logs
	KubectlLogsOptions *kubectllogs.LogsOptions
	Cluster            string
}

// Complete ensures that options are valid and marshals them if necessary
func (o *CommandLogsOptions) Complete(cmd *cobra.Command, args []string, f util.Factory) error {
	if o.Cluster == "" {
		return fmt.Errorf("must specify a cluster")
	}

	// print correct usage message when the given arguments are invalid
	switch len(args) {
	case 0:
		if len(o.KubectlLogsOptions.Selector) == 0 {
			return cmdutil.UsageErrorf(cmd, "%s", logsUsageErrStr)
		}
	case 1:
		if len(o.KubectlLogsOptions.Selector) != 0 {
			return cmdutil.UsageErrorf(cmd, "only a selector (-l) or a POD name is allowed")
		}
	case 2:
	default:
		return cmdutil.UsageErrorf(cmd, "%s", logsUsageErrStr)
	}

	memberFactory, err := f.FactoryForMemberCluster(o.Cluster)
	if err != nil {
		return err
	}
	return o.KubectlLogsOptions.Complete(memberFactory, cmd, args)
}

// Validate checks to the LogsOptions to see if there is sufficient information run the command
func (o *CommandLogsOptions) Validate() error {
	return o.KubectlLogsOptions.Validate()
}

// Run retrieves a pod log
func (o *CommandLogsOptions) Run() error {
	return o.KubectlLogsOptions.RunLogs()
}