github.com/willmtemple/docker@v1.7.0-rc2/daemon/top.go (about)

     1  package daemon
     2  
     3  import (
     4  	"fmt"
     5  	"os/exec"
     6  	"strconv"
     7  	"strings"
     8  
     9  	"github.com/docker/docker/api/types"
    10  )
    11  
    12  func (daemon *Daemon) ContainerTop(name string, psArgs string) (*types.ContainerProcessList, error) {
    13  	if psArgs == "" {
    14  		psArgs = "-ef"
    15  	}
    16  
    17  	container, err := daemon.Get(name)
    18  	if err != nil {
    19  		return nil, err
    20  	}
    21  
    22  	if !container.IsRunning() {
    23  		return nil, fmt.Errorf("Container %s is not running", name)
    24  	}
    25  
    26  	pids, err := daemon.ExecutionDriver().GetPidsForContainer(container.ID)
    27  	if err != nil {
    28  		return nil, err
    29  	}
    30  
    31  	output, err := exec.Command("ps", strings.Split(psArgs, " ")...).Output()
    32  	if err != nil {
    33  		return nil, fmt.Errorf("Error running ps: %s", err)
    34  	}
    35  
    36  	procList := &types.ContainerProcessList{}
    37  
    38  	lines := strings.Split(string(output), "\n")
    39  	procList.Titles = strings.Fields(lines[0])
    40  
    41  	pidIndex := -1
    42  	for i, name := range procList.Titles {
    43  		if name == "PID" {
    44  			pidIndex = i
    45  		}
    46  	}
    47  	if pidIndex == -1 {
    48  		return nil, fmt.Errorf("Couldn't find PID field in ps output")
    49  	}
    50  
    51  	for _, line := range lines[1:] {
    52  		if len(line) == 0 {
    53  			continue
    54  		}
    55  		fields := strings.Fields(line)
    56  		p, err := strconv.Atoi(fields[pidIndex])
    57  		if err != nil {
    58  			return nil, fmt.Errorf("Unexpected pid '%s': %s", fields[pidIndex], err)
    59  		}
    60  
    61  		for _, pid := range pids {
    62  			if pid == p {
    63  				// Make sure number of fields equals number of header titles
    64  				// merging "overhanging" fields
    65  				process := fields[:len(procList.Titles)-1]
    66  				process = append(process, strings.Join(fields[len(procList.Titles)-1:], " "))
    67  				procList.Processes = append(procList.Processes, process)
    68  			}
    69  		}
    70  	}
    71  	return procList, nil
    72  }