github.com/containerd/nerdctl@v1.7.7/cmd/nerdctl/container_top.go (about)

     1  /*
     2     Copyright The containerd Authors.
     3  
     4     Licensed under the Apache License, Version 2.0 (the "License");
     5     you may not use this file except in compliance with the License.
     6     You may obtain a copy of the License at
     7  
     8         http://www.apache.org/licenses/LICENSE-2.0
     9  
    10     Unless required by applicable law or agreed to in writing, software
    11     distributed under the License is distributed on an "AS IS" BASIS,
    12     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13     See the License for the specific language governing permissions and
    14     limitations under the License.
    15  */
    16  
    17  package main
    18  
    19  import (
    20  	"errors"
    21  	"fmt"
    22  
    23  	"github.com/containerd/containerd"
    24  	"github.com/containerd/nerdctl/pkg/api/types"
    25  	"github.com/containerd/nerdctl/pkg/clientutil"
    26  	"github.com/containerd/nerdctl/pkg/cmd/container"
    27  	"github.com/containerd/nerdctl/pkg/infoutil"
    28  	"github.com/containerd/nerdctl/pkg/rootlessutil"
    29  
    30  	"github.com/spf13/cobra"
    31  )
    32  
    33  func newTopCommand() *cobra.Command {
    34  	var topCommand = &cobra.Command{
    35  		Use:               "top CONTAINER [ps OPTIONS]",
    36  		Args:              cobra.MinimumNArgs(1),
    37  		Short:             "Display the running processes of a container",
    38  		RunE:              topAction,
    39  		ValidArgsFunction: topShellComplete,
    40  		SilenceUsage:      true,
    41  		SilenceErrors:     true,
    42  	}
    43  	topCommand.Flags().SetInterspersed(false)
    44  	return topCommand
    45  }
    46  
    47  func topAction(cmd *cobra.Command, args []string) error {
    48  	// NOTE: rootless container does not rely on cgroupv1.
    49  	// more details about possible ways to resolve this concern: #223
    50  	globalOptions, err := processRootCmdFlags(cmd)
    51  	if err != nil {
    52  		return err
    53  	}
    54  	if rootlessutil.IsRootless() && infoutil.CgroupsVersion() == "1" {
    55  		return fmt.Errorf("top requires cgroup v2 for rootless containers, see https://rootlesscontaine.rs/getting-started/common/cgroup2/")
    56  	}
    57  
    58  	if globalOptions.CgroupManager == "none" {
    59  		return errors.New("cgroup manager must not be \"none\"")
    60  	}
    61  	client, ctx, cancel, err := clientutil.NewClient(cmd.Context(), globalOptions.Namespace, globalOptions.Address)
    62  	if err != nil {
    63  		return err
    64  	}
    65  	defer cancel()
    66  	return container.Top(ctx, client, args, types.ContainerTopOptions{
    67  		Stdout:   cmd.OutOrStdout(),
    68  		GOptions: globalOptions,
    69  	})
    70  
    71  }
    72  
    73  func topShellComplete(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
    74  	// show running container names
    75  	statusFilterFn := func(st containerd.ProcessStatus) bool {
    76  		return st == containerd.Running
    77  	}
    78  	return shellCompleteContainerNames(cmd, statusFilterFn)
    79  }