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moby--moby/daemon/top_unix.go
Daniel Nephin 4f0d95fa6e Add canonical import comment
Signed-off-by: Daniel Nephin <dnephin@docker.com>
2018-02-05 16:51:57 -05:00

157 lines
3.8 KiB
Go

//+build !windows
package daemon // import "github.com/docker/docker/daemon"
import (
"context"
"fmt"
"os/exec"
"regexp"
"strconv"
"strings"
"github.com/docker/docker/api/types/container"
)
func validatePSArgs(psArgs string) error {
// NOTE: \\s does not detect unicode whitespaces.
// So we use fieldsASCII instead of strings.Fields in parsePSOutput.
// See https://github.com/docker/docker/pull/24358
// nolint: gosimple
re := regexp.MustCompile("\\s+([^\\s]*)=\\s*(PID[^\\s]*)")
for _, group := range re.FindAllStringSubmatch(psArgs, -1) {
if len(group) >= 3 {
k := group[1]
v := group[2]
if k != "pid" {
return fmt.Errorf("specifying \"%s=%s\" is not allowed", k, v)
}
}
}
return nil
}
// fieldsASCII is similar to strings.Fields but only allows ASCII whitespaces
func fieldsASCII(s string) []string {
fn := func(r rune) bool {
switch r {
case '\t', '\n', '\f', '\r', ' ':
return true
}
return false
}
return strings.FieldsFunc(s, fn)
}
func appendProcess2ProcList(procList *container.ContainerTopOKBody, fields []string) {
// Make sure number of fields equals number of header titles
// merging "overhanging" fields
process := fields[:len(procList.Titles)-1]
process = append(process, strings.Join(fields[len(procList.Titles)-1:], " "))
procList.Processes = append(procList.Processes, process)
}
func hasPid(procs []uint32, pid int) bool {
for _, p := range procs {
if int(p) == pid {
return true
}
}
return false
}
func parsePSOutput(output []byte, procs []uint32) (*container.ContainerTopOKBody, error) {
procList := &container.ContainerTopOKBody{}
lines := strings.Split(string(output), "\n")
procList.Titles = fieldsASCII(lines[0])
pidIndex := -1
for i, name := range procList.Titles {
if name == "PID" {
pidIndex = i
}
}
if pidIndex == -1 {
return nil, fmt.Errorf("Couldn't find PID field in ps output")
}
// loop through the output and extract the PID from each line
// fixing #30580, be able to display thread line also when "m" option used
// in "docker top" client command
preContainedPidFlag := false
for _, line := range lines[1:] {
if len(line) == 0 {
continue
}
fields := fieldsASCII(line)
var (
p int
err error
)
if fields[pidIndex] == "-" {
if preContainedPidFlag {
appendProcess2ProcList(procList, fields)
}
continue
}
p, err = strconv.Atoi(fields[pidIndex])
if err != nil {
return nil, fmt.Errorf("Unexpected pid '%s': %s", fields[pidIndex], err)
}
if hasPid(procs, p) {
preContainedPidFlag = true
appendProcess2ProcList(procList, fields)
continue
}
preContainedPidFlag = false
}
return procList, nil
}
// ContainerTop lists the processes running inside of the given
// container by calling ps with the given args, or with the flags
// "-ef" if no args are given. An error is returned if the container
// is not found, or is not running, or if there are any problems
// running ps, or parsing the output.
func (daemon *Daemon) ContainerTop(name string, psArgs string) (*container.ContainerTopOKBody, error) {
if psArgs == "" {
psArgs = "-ef"
}
if err := validatePSArgs(psArgs); err != nil {
return nil, err
}
container, err := daemon.GetContainer(name)
if err != nil {
return nil, err
}
if !container.IsRunning() {
return nil, errNotRunning(container.ID)
}
if container.IsRestarting() {
return nil, errContainerIsRestarting(container.ID)
}
procs, err := daemon.containerd.ListPids(context.Background(), container.ID)
if err != nil {
return nil, err
}
output, err := exec.Command("ps", strings.Split(psArgs, " ")...).Output()
if err != nil {
return nil, fmt.Errorf("Error running ps: %v", err)
}
procList, err := parsePSOutput(output, procs)
if err != nil {
return nil, err
}
daemon.LogContainerEvent(container, "top")
return procList, nil
}