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Add initial logging to libcontainer

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Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
This commit is contained in:
Michael Crosby 2014-03-13 10:35:16 -07:00
parent ff10ab55d2
commit f7eec3dd13
6 changed files with 68 additions and 18 deletions
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3
libcontainer/nsinit/command.go
View file

@ -1,6 +1,7 @@
package nsinit
import (
"fmt"
"github.com/dotcloud/docker/pkg/libcontainer"
"github.com/dotcloud/docker/pkg/system"
"os"
@ -25,7 +26,7 @@ func (c *DefaultCommandFactory) Create(container *libcontainer.Container, consol
// get our binary name from arg0 so we can always reexec ourself
command := exec.Command(os.Args[0], append([]string{
"-console", console,
"-pipe", "3",
"-pipe", fmt.Sprint(pipe.Fd()),
"-root", c.Root,
"init"}, args...)...)

16
libcontainer/nsinit/exec.go
View file

@ -28,6 +28,7 @@ func (ns *linuxNs) Exec(container *libcontainer.Container, term Terminal, args [
}
if container.Tty {
ns.logger.Println("creating master and console")
master, console, err = system.CreateMasterAndConsole()
if err != nil {
return -1, err
@ -36,31 +37,40 @@ func (ns *linuxNs) Exec(container *libcontainer.Container, term Terminal, args [
}
command := ns.commandFactory.Create(container, console, syncPipe.child, args)
ns.logger.Println("attach terminal to command")
if err := term.Attach(command); err != nil {
return -1, err
}
defer term.Close()
ns.logger.Println("starting command")
if err := command.Start(); err != nil {
return -1, err
}
ns.logger.Printf("writting pid %d to file\n", command.Process.Pid)
if err := ns.stateWriter.WritePid(command.Process.Pid); err != nil {
command.Process.Kill()
return -1, err
}
defer ns.stateWriter.DeletePid()
defer func() {
ns.logger.Println("removing pid file")
ns.stateWriter.DeletePid()
}()
// Do this before syncing with child so that no children
// can escape the cgroup
ns.logger.Println("setting cgroups")
if err := ns.SetupCgroups(container, command.Process.Pid); err != nil {
command.Process.Kill()
return -1, err
}
ns.logger.Println("setting up network")
if err := ns.InitializeNetworking(container, command.Process.Pid, syncPipe); err != nil {
command.Process.Kill()
return -1, err
}
ns.logger.Println("closing sync pipe with child")
// Sync with child
syncPipe.Close()
@ -69,7 +79,9 @@ func (ns *linuxNs) Exec(container *libcontainer.Container, term Terminal, args [
return -1, err
}
}
return command.ProcessState.Sys().(syscall.WaitStatus).ExitStatus(), nil
status := command.ProcessState.Sys().(syscall.WaitStatus).ExitStatus()
ns.logger.Printf("process exited with status %d\n", status)
return status, err
}
func (ns *linuxNs) SetupCgroups(container *libcontainer.Container, nspid int) error {

3
libcontainer/nsinit/execin.go
View file

@ -14,6 +14,7 @@ import (
// ExecIn uses an existing pid and joins the pid's namespaces with the new command.
func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []string) (int, error) {
ns.logger.Println("unshare namespaces")
for _, ns := range container.Namespaces {
if err := system.Unshare(ns.Value); err != nil {
return -1, err
@ -33,6 +34,7 @@ func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []s
// foreach namespace fd, use setns to join an existing container's namespaces
for _, fd := range fds {
if fd > 0 {
ns.logger.Printf("setns on %d\n", fd)
if err := system.Setns(fd, 0); err != nil {
closeFds()
return -1, fmt.Errorf("setns %s", err)
@ -44,6 +46,7 @@ func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []s
// if the container has a new pid and mount namespace we need to
// remount proc and sys to pick up the changes
if container.Namespaces.Contains("NEWNS") && container.Namespaces.Contains("NEWPID") {
ns.logger.Println("forking to remount /proc and /sys")
pid, err := system.Fork()
if err != nil {
return -1, err

9
libcontainer/nsinit/init.go
View file

@ -29,9 +29,11 @@ func (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, consol
syncPipe.Close()
return err
}
ns.logger.Println("received context from parent")
syncPipe.Close()
if console != "" {
ns.logger.Printf("setting up %s as console\n", console)
slave, err := system.OpenTerminal(console, syscall.O_RDWR)
if err != nil {
return fmt.Errorf("open terminal %s", err)
@ -51,6 +53,7 @@ func (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, consol
if err := system.ParentDeathSignal(); err != nil {
return fmt.Errorf("parent death signal %s", err)
}
ns.logger.Println("setup mount namespace")
if err := setupNewMountNamespace(rootfs, container.Mounts, console, container.ReadonlyFs, container.NoPivotRoot); err != nil {
return fmt.Errorf("setup mount namespace %s", err)
}
@ -64,9 +67,13 @@ func (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, consol
return fmt.Errorf("finalize namespace %s", err)
}
if err := apparmor.ApplyProfile(os.Getpid(), container.Context["apparmor_profile"]); err != nil {
if profile := container.Context["apparmor_profile"]; profile != "" {
ns.logger.Printf("setting apparmor prifile %s\n", profile)
if err := apparmor.ApplyProfile(os.Getpid(), profile); err != nil {
return err
}
}
ns.logger.Printf("execing %s\n", args[0])
return system.Execv(args[0], args[0:], container.Env)
}

5
libcontainer/nsinit/nsinit.go
View file

@ -2,6 +2,7 @@ package nsinit
import (
"github.com/dotcloud/docker/pkg/libcontainer"
"log"
)
// NsInit is an interface with the public facing methods to provide high level
@ -16,11 +17,13 @@ type linuxNs struct {
root string
commandFactory CommandFactory
stateWriter StateWriter
logger *log.Logger
}
func NewNsInit(command CommandFactory, state StateWriter) NsInit {
func NewNsInit(command CommandFactory, state StateWriter, logger *log.Logger) NsInit {
return &linuxNs{
commandFactory: command,
stateWriter: state,
logger: logger,
}
}

46
libcontainer/nsinit/nsinit/main.go
View file

@ -5,6 +5,7 @@ import (
"flag"
"github.com/dotcloud/docker/pkg/libcontainer"
"github.com/dotcloud/docker/pkg/libcontainer/nsinit"
"io"
"io/ioutil"
"log"
"os"
@ -13,7 +14,7 @@ import (
)
var (
root, console string
root, console, logs string
pipeFd int
)
@ -21,6 +22,7 @@ func registerFlags() {
flag.StringVar(&console, "console", "", "console (pty slave) path")
flag.IntVar(&pipeFd, "pipe", 0, "sync pipe fd")
flag.StringVar(&root, "root", ".", "root for storing configuration data")
flag.StringVar(&logs, "log", "none", "set stderr or a filepath to enable logging")
flag.Parse()
}
@ -35,7 +37,12 @@ func main() {
if err != nil {
log.Fatalf("Unable to load container: %s", err)
}
ns, err := newNsInit()
l, err := getLogger("[exec] ")
if err != nil {
log.Fatal(err)
}
ns, err := newNsInit(l)
if err != nil {
log.Fatalf("Unable to initialize nsinit: %s", err)
}
@ -46,7 +53,7 @@ func main() {
nspid, err := readPid()
if err != nil {
if !os.IsNotExist(err) {
log.Fatalf("Unable to read pid: %s", err)
l.Fatalf("Unable to read pid: %s", err)
}
}
if nspid > 0 {
@ -56,26 +63,26 @@ func main() {
exitCode, err = ns.Exec(container, term, flag.Args()[1:])
}
if err != nil {
log.Fatalf("Failed to exec: %s", err)
l.Fatalf("Failed to exec: %s", err)
}
os.Exit(exitCode)
case "init": // this is executed inside of the namespace to setup the container
cwd, err := os.Getwd()
if err != nil {
log.Fatal(err)
l.Fatal(err)
}
if flag.NArg() < 2 {
log.Fatalf("wrong number of argments %d", flag.NArg())
l.Fatalf("wrong number of argments %d", flag.NArg())
}
syncPipe, err := nsinit.NewSyncPipeFromFd(0, uintptr(pipeFd))
if err != nil {
log.Fatalf("Unable to create sync pipe: %s", err)
l.Fatalf("Unable to create sync pipe: %s", err)
}
if err := ns.Init(container, cwd, console, syncPipe, flag.Args()[1:]); err != nil {
log.Fatalf("Unable to initialize for container: %s", err)
l.Fatalf("Unable to initialize for container: %s", err)
}
default:
log.Fatalf("command not supported for nsinit %s", flag.Arg(0))
l.Fatalf("command not supported for nsinit %s", flag.Arg(0))
}
}
@ -105,6 +112,23 @@ func readPid() (int, error) {
return pid, nil
}
func newNsInit() (nsinit.NsInit, error) {
return nsinit.NewNsInit(&nsinit.DefaultCommandFactory{root}, &nsinit.DefaultStateWriter{root}), nil
func newNsInit(l *log.Logger) (nsinit.NsInit, error) {
return nsinit.NewNsInit(&nsinit.DefaultCommandFactory{root}, &nsinit.DefaultStateWriter{root}, l), nil
}
func getLogger(prefix string) (*log.Logger, error) {
var w io.Writer
switch logs {
case "", "none":
w = ioutil.Discard
case "stderr":
w = os.Stderr
default: // we have a filepath
f, err := os.OpenFile(logs, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0755)
if err != nil {
return nil, err
}
w = f
}
return log.New(w, prefix, log.LstdFlags), nil
}