github.com/psychoss/docker@v1.9.0/daemon/top_unix.go (about)

     1  //+build !windows
     2  
     3  package daemon
     4  
     5  import (
     6  	"os/exec"
     7  	"strconv"
     8  	"strings"
     9  
    10  	"github.com/docker/docker/api/types"
    11  	derr "github.com/docker/docker/errors"
    12  )
    13  
    14  // ContainerTop lists the processes running inside of the given
    15  // container by calling ps with the given args, or with the flags
    16  // "-ef" if no args are given.  An error is returned if the container
    17  // is not found, or is not running, or if there are any problems
    18  // running ps, or parsing the output.
    19  func (daemon *Daemon) ContainerTop(name string, psArgs string) (*types.ContainerProcessList, error) {
    20  	if psArgs == "" {
    21  		psArgs = "-ef"
    22  	}
    23  
    24  	container, err := daemon.Get(name)
    25  	if err != nil {
    26  		return nil, err
    27  	}
    28  
    29  	if !container.IsRunning() {
    30  		return nil, derr.ErrorCodeNotRunning.WithArgs(name)
    31  	}
    32  
    33  	pids, err := daemon.ExecutionDriver().GetPidsForContainer(container.ID)
    34  	if err != nil {
    35  		return nil, err
    36  	}
    37  
    38  	output, err := exec.Command("ps", strings.Split(psArgs, " ")...).Output()
    39  	if err != nil {
    40  		return nil, derr.ErrorCodePSError.WithArgs(err)
    41  	}
    42  
    43  	procList := &types.ContainerProcessList{}
    44  
    45  	lines := strings.Split(string(output), "\n")
    46  	procList.Titles = strings.Fields(lines[0])
    47  
    48  	pidIndex := -1
    49  	for i, name := range procList.Titles {
    50  		if name == "PID" {
    51  			pidIndex = i
    52  		}
    53  	}
    54  	if pidIndex == -1 {
    55  		return nil, derr.ErrorCodeNoPID
    56  	}
    57  
    58  	// loop through the output and extract the PID from each line
    59  	for _, line := range lines[1:] {
    60  		if len(line) == 0 {
    61  			continue
    62  		}
    63  		fields := strings.Fields(line)
    64  		p, err := strconv.Atoi(fields[pidIndex])
    65  		if err != nil {
    66  			return nil, derr.ErrorCodeBadPID.WithArgs(fields[pidIndex], err)
    67  		}
    68  
    69  		for _, pid := range pids {
    70  			if pid == p {
    71  				// Make sure number of fields equals number of header titles
    72  				// merging "overhanging" fields
    73  				process := fields[:len(procList.Titles)-1]
    74  				process = append(process, strings.Join(fields[len(procList.Titles)-1:], " "))
    75  				procList.Processes = append(procList.Processes, process)
    76  			}
    77  		}
    78  	}
    79  	container.logEvent("top")
    80  	return procList, nil
    81  }