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Write logs to stderr by default
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Minor refactoring to use the filePair struct for both init sock and log pipe

Co-authored-by: Julia Nedialkova <julianedialkova@hotmail.com>
Signed-off-by: Georgi Sabev <georgethebeatle@gmail.com>
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@georgethebeatle @yulianedyalkova
georgethebeatle and yulianedyalkova committed Apr 24, 2019
1 parent 68b4ff5 commit a146081
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Showing 7 changed files with 56 additions and 55 deletions.
34 changes: 16 additions & 18 deletions libcontainer/container_linux.go
View file
Expand Up @@ -439,24 +439,24 @@ func (c *linuxContainer) includeExecFifo(cmd *exec.Cmd) error {
}

func (c *linuxContainer) newParentProcess(p *Process) (parentProcess, error) {
parentPipe, childPipe, err := utils.NewSockPair("init")
parentInitPipe, childInitPipe, err := utils.NewSockPair("init")
if err != nil {
return nil, newSystemErrorWithCause(err, "creating new init pipe")
}
messagePipe := readWritePair{parentPipe, childPipe}
messageSockPair := filePair{parentInitPipe, childInitPipe}

r, w, err := os.Pipe()
parentLogPipe, childLogPipe, err := os.Pipe()
if err != nil {
return nil, fmt.Errorf("Unable to create the log pipe: %s", err)
}
logPipe := readWritePair{r, w}
logFilePair := filePair{parentLogPipe, childLogPipe}

cmd, err := c.commandTemplate(p, childPipe, logPipe.w)
cmd, err := c.commandTemplate(p, childInitPipe, childLogPipe)
if err != nil {
return nil, newSystemErrorWithCause(err, "creating new command template")
}
if !p.Init {
return c.newSetnsProcess(p, cmd, messagePipe, logPipe)
return c.newSetnsProcess(p, cmd, messageSockPair, logFilePair)
}

// We only set up fifoFd if we're not doing a `runc exec`. The historic
Expand All @@ -467,10 +467,10 @@ func (c *linuxContainer) newParentProcess(p *Process) (parentProcess, error) {
if err := c.includeExecFifo(cmd); err != nil {
return nil, newSystemErrorWithCause(err, "including execfifo in cmd.Exec setup")
}
return c.newInitProcess(p, cmd, messagePipe, logPipe)
return c.newInitProcess(p, cmd, messageSockPair, logFilePair)
}

func (c *linuxContainer) commandTemplate(p *Process, childPipe *os.File, logPipe *os.File) (*exec.Cmd, error) {
func (c *linuxContainer) commandTemplate(p *Process, childInitPipe *os.File, childLogPipe *os.File) (*exec.Cmd, error) {
cmd := exec.Command(c.initPath, c.initArgs[1:]...)
cmd.Args[0] = c.initArgs[0]
cmd.Stdin = p.Stdin
Expand All @@ -488,13 +488,13 @@ func (c *linuxContainer) commandTemplate(p *Process, childPipe *os.File, logPipe
fmt.Sprintf("_LIBCONTAINER_CONSOLE=%d", stdioFdCount+len(cmd.ExtraFiles)-1),
)
}
cmd.ExtraFiles = append(cmd.ExtraFiles, childPipe)
cmd.ExtraFiles = append(cmd.ExtraFiles, childInitPipe)
cmd.Env = append(cmd.Env,
fmt.Sprintf("_LIBCONTAINER_INITPIPE=%d", stdioFdCount+len(cmd.ExtraFiles)-1),
fmt.Sprintf("_LIBCONTAINER_STATEDIR=%s", c.root),
)

cmd.ExtraFiles = append(cmd.ExtraFiles, logPipe)
cmd.ExtraFiles = append(cmd.ExtraFiles, childLogPipe)
cmd.Env = append(cmd.Env,
fmt.Sprintf("_LIBCONTAINER_LOGPIPE=%d", stdioFdCount+len(cmd.ExtraFiles)-1),
fmt.Sprintf("_LIBCONTAINER_LOGLEVEL=%s", p.LogLevel),
Expand All @@ -509,7 +509,7 @@ func (c *linuxContainer) commandTemplate(p *Process, childPipe *os.File, logPipe
return cmd, nil
}

func (c *linuxContainer) newInitProcess(p *Process, cmd *exec.Cmd, initPipe, logPipe readWritePair) (*initProcess, error) {
func (c *linuxContainer) newInitProcess(p *Process, cmd *exec.Cmd, messageSockPair, logFilePair filePair) (*initProcess, error) {
cmd.Env = append(cmd.Env, "_LIBCONTAINER_INITTYPE="+string(initStandard))
nsMaps := make(map[configs.NamespaceType]string)
for _, ns := range c.config.Namespaces {
Expand All @@ -524,9 +524,8 @@ func (c *linuxContainer) newInitProcess(p *Process, cmd *exec.Cmd, initPipe, log
}
init := &initProcess{
cmd: cmd,
childPipe: initPipe.w,
parentPipe: initPipe.r,
logPipe: logPipe,
messageSockPair: messageSockPair,
logFilePair: logFilePair,
manager: c.cgroupManager,
intelRdtManager: c.intelRdtManager,
config: c.newInitConfig(p),
Expand All @@ -539,7 +538,7 @@ func (c *linuxContainer) newInitProcess(p *Process, cmd *exec.Cmd, initPipe, log
return init, nil
}

func (c *linuxContainer) newSetnsProcess(p *Process, cmd *exec.Cmd, nsPipe, logPipe readWritePair) (*setnsProcess, error) {
func (c *linuxContainer) newSetnsProcess(p *Process, cmd *exec.Cmd, messageSockPair, logFilePair filePair) (*setnsProcess, error) {
cmd.Env = append(cmd.Env, "_LIBCONTAINER_INITTYPE="+string(initSetns))
state, err := c.currentState()
if err != nil {
Expand All @@ -556,9 +555,8 @@ func (c *linuxContainer) newSetnsProcess(p *Process, cmd *exec.Cmd, nsPipe, logP
cgroupPaths: c.cgroupManager.GetPaths(),
rootlessCgroups: c.config.RootlessCgroups,
intelRdtPath: state.IntelRdtPath,
childPipe: nsPipe.w,
parentPipe: nsPipe.r,
logPipe: logPipe,
messageSockPair: messageSockPair,
logFilePair: logFilePair,
config: c.newInitConfig(p),
process: p,
bootstrapData: data,
Expand Down
6 changes: 3 additions & 3 deletions libcontainer/logs/logs.go
View file
Expand Up @@ -13,7 +13,7 @@ import (
)

var (
mutex = &sync.Mutex{}
configureMutex = sync.Mutex{}
// loggingConfigured will be set once logging has been configured via invoking `ConfigureLogging`.
// Subsequent invocations of `ConfigureLogging` would be no-op
loggingConfigured = false
Expand Down Expand Up @@ -64,8 +64,8 @@ func processEntry(text []byte) {
}

func ConfigureLogging(config Config) error {
mutex.Lock()
defer mutex.Unlock()
configureMutex.Lock()
defer configureMutex.Unlock()

if loggingConfigured {
logrus.Debug("logging has already been configured")
Expand Down
4 changes: 2 additions & 2 deletions libcontainer/nsenter/nsenter_test.go
View file
Expand Up @@ -22,8 +22,8 @@ type pid struct {
}

type logentry struct {
Msg string
Level string
Msg string `json:"msg"`
Level string `json:"level"`
}

func TestNsenterValidPaths(t *testing.T) {
Expand Down
58 changes: 28 additions & 30 deletions libcontainer/process_linux.go
View file
Expand Up @@ -52,16 +52,15 @@ type parentProcess interface {
forwardChildLogs()
}

type readWritePair struct {
r *os.File
w *os.File
type filePair struct {
parent *os.File
child *os.File
}

type setnsProcess struct {
cmd *exec.Cmd
parentPipe *os.File
childPipe *os.File
logPipe readWritePair
messageSockPair filePair
logFilePair filePair
cgroupPaths map[string]string
rootlessCgroups bool
intelRdtPath string
Expand All @@ -85,16 +84,16 @@ func (p *setnsProcess) signal(sig os.Signal) error {
}

func (p *setnsProcess) start() (err error) {
defer p.parentPipe.Close()
defer p.messageSockPair.parent.Close()
err = p.cmd.Start()
// close the write-side of the pipes (controlled by child)
p.childPipe.Close()
p.logPipe.w.Close()
p.messageSockPair.child.Close()
p.logFilePair.child.Close()
if err != nil {
return newSystemErrorWithCause(err, "starting setns process")
}
if p.bootstrapData != nil {
if _, err := io.Copy(p.parentPipe, p.bootstrapData); err != nil {
if _, err := io.Copy(p.messageSockPair.parent, p.bootstrapData); err != nil {
return newSystemErrorWithCause(err, "copying bootstrap data to pipe")
}
}
Expand All @@ -120,11 +119,11 @@ func (p *setnsProcess) start() (err error) {
if err := setupRlimits(p.config.Rlimits, p.pid()); err != nil {
return newSystemErrorWithCause(err, "setting rlimits for process")
}
if err := utils.WriteJSON(p.parentPipe, p.config); err != nil {
if err := utils.WriteJSON(p.messageSockPair.parent, p.config); err != nil {
return newSystemErrorWithCause(err, "writing config to pipe")
}

ierr := parseSync(p.parentPipe, func(sync *syncT) error {
ierr := parseSync(p.messageSockPair.parent, func(sync *syncT) error {
switch sync.Type {
case procReady:
// This shouldn't happen.
Expand All @@ -137,7 +136,7 @@ func (p *setnsProcess) start() (err error) {
}
})

if err := unix.Shutdown(int(p.parentPipe.Fd()), unix.SHUT_WR); err != nil {
if err := unix.Shutdown(int(p.messageSockPair.parent.Fd()), unix.SHUT_WR); err != nil {
return newSystemErrorWithCause(err, "calling shutdown on init pipe")
}
// Must be done after Shutdown so the child will exit and we can wait for it.
Expand All @@ -163,7 +162,7 @@ func (p *setnsProcess) execSetns() error {
return newSystemError(&exec.ExitError{ProcessState: status})
}
var pid *pid
if err := json.NewDecoder(p.parentPipe).Decode(&pid); err != nil {
if err := json.NewDecoder(p.messageSockPair.parent).Decode(&pid); err != nil {
p.cmd.Wait()
return newSystemErrorWithCause(err, "reading pid from init pipe")
}
Expand Down Expand Up @@ -217,14 +216,13 @@ func (p *setnsProcess) setExternalDescriptors(newFds []string) {
}

func (p *setnsProcess) forwardChildLogs() {
go logs.ForwardLogs(p.logPipe.r)
go logs.ForwardLogs(p.logFilePair.parent)
}

type initProcess struct {
cmd *exec.Cmd
parentPipe *os.File
childPipe *os.File
logPipe readWritePair
messageSockPair filePair
logFilePair filePair
config *initConfig
manager cgroups.Manager
intelRdtManager intelrdt.Manager
Expand All @@ -246,7 +244,7 @@ func (p *initProcess) externalDescriptors() []string {
// getChildPid receives the final child's pid over the provided pipe.
func (p *initProcess) getChildPid() (int, error) {
var pid pid
if err := json.NewDecoder(p.parentPipe).Decode(&pid); err != nil {
if err := json.NewDecoder(p.messageSockPair.parent).Decode(&pid); err != nil {
p.cmd.Wait()
return -1, err
}
Expand Down Expand Up @@ -282,12 +280,12 @@ func (p *initProcess) waitForChildExit(childPid int) error {
}

func (p *initProcess) start() error {
defer p.parentPipe.Close()
defer p.messageSockPair.parent.Close()
err := p.cmd.Start()
p.process.ops = p
// close the write-side of the pipes (controlled by child)
p.childPipe.Close()
p.logPipe.w.Close()
p.messageSockPair.child.Close()
p.logFilePair.child.Close()
if err != nil {
p.process.ops = nil
return newSystemErrorWithCause(err, "starting init process command")
Expand All @@ -313,7 +311,7 @@ func (p *initProcess) start() error {
}
}()

if _, err := io.Copy(p.parentPipe, p.bootstrapData); err != nil {
if _, err := io.Copy(p.messageSockPair.parent, p.bootstrapData); err != nil {
return newSystemErrorWithCause(err, "copying bootstrap data to pipe")
}
childPid, err := p.getChildPid()
Expand Down Expand Up @@ -341,7 +339,7 @@ func (p *initProcess) start() error {
}
// Now it's time to setup cgroup namesapce
if p.config.Config.Namespaces.Contains(configs.NEWCGROUP) && p.config.Config.Namespaces.PathOf(configs.NEWCGROUP) == "" {
if _, err := p.parentPipe.Write([]byte{createCgroupns}); err != nil {
if _, err := p.messageSockPair.parent.Write([]byte{createCgroupns}); err != nil {
return newSystemErrorWithCause(err, "sending synchronization value to init process")
}
}
Expand All @@ -368,7 +366,7 @@ func (p *initProcess) start() error {
sentResume bool
)

ierr := parseSync(p.parentPipe, func(sync *syncT) error {
ierr := parseSync(p.messageSockPair.parent, func(sync *syncT) error {
switch sync.Type {
case procReady:
// set rlimits, this has to be done here because we lose permissions
Expand Down Expand Up @@ -404,7 +402,7 @@ func (p *initProcess) start() error {
}
}
// Sync with child.
if err := writeSync(p.parentPipe, procRun); err != nil {
if err := writeSync(p.messageSockPair.parent, procRun); err != nil {
return newSystemErrorWithCause(err, "writing syncT 'run'")
}
sentRun = true
Expand Down Expand Up @@ -433,7 +431,7 @@ func (p *initProcess) start() error {
}
}
// Sync with child.
if err := writeSync(p.parentPipe, procResume); err != nil {
if err := writeSync(p.messageSockPair.parent, procResume); err != nil {
return newSystemErrorWithCause(err, "writing syncT 'resume'")
}
sentResume = true
Expand All @@ -450,7 +448,7 @@ func (p *initProcess) start() error {
if p.config.Config.Namespaces.Contains(configs.NEWNS) && !sentResume {
return newSystemError(fmt.Errorf("could not synchronise after executing prestart hooks with container process"))
}
if err := unix.Shutdown(int(p.parentPipe.Fd()), unix.SHUT_WR); err != nil {
if err := unix.Shutdown(int(p.messageSockPair.parent.Fd()), unix.SHUT_WR); err != nil {
return newSystemErrorWithCause(err, "shutting down init pipe")
}

Expand Down Expand Up @@ -494,7 +492,7 @@ func (p *initProcess) sendConfig() error {
// send the config to the container's init process, we don't use JSON Encode
// here because there might be a problem in JSON decoder in some cases, see:
// https://github.com/docker/docker/issues/14203#issuecomment-174177790
return utils.WriteJSON(p.parentPipe, p.config)
return utils.WriteJSON(p.messageSockPair.parent, p.config)
}

func (p *initProcess) createNetworkInterfaces() error {
Expand Down Expand Up @@ -527,7 +525,7 @@ func (p *initProcess) setExternalDescriptors(newFds []string) {
}

func (p *initProcess) forwardChildLogs() {
go logs.ForwardLogs(p.logPipe.r)
go logs.ForwardLogs(p.logFilePair.parent)
}

func getPipeFds(pid int) ([]string, error) {
Expand Down
2 changes: 1 addition & 1 deletion main.go
View file
Expand Up @@ -87,7 +87,7 @@ func main() {
},
cli.StringFlag{
Name: "log",
Value: "/dev/null",
Value: "/dev/stderr",
Usage: "set the log file path where internal debug information is written",
},
cli.StringFlag{
Expand Down
5 changes: 5 additions & 0 deletions tests/integration/debug.bats
View file
Expand Up @@ -16,6 +16,11 @@ function teardown() {
runc --debug run test_hello
echo "${output}"
[ "$status" -eq 0 ]

# check expected debug output was sent to stderr
[[ "${output}" == *"level=debug"* ]]
[[ "${output}" == *"nsexec started"* ]]
[[ "${output}" == *"child process in init()"* ]]
}

@test "global --debug to --log" {
Expand Down
2 changes: 1 addition & 1 deletion tests/integration/helpers.bash
View file
Expand Up @@ -65,7 +65,7 @@ function runc() {

# Raw wrapper for runc.
function __runc() {
"$RUNC" ${RUNC_USE_SYSTEMD+--systemd-cgroup} --log /proc/self/fd/2 --root "$ROOT" "$@"
"$RUNC" ${RUNC_USE_SYSTEMD+--systemd-cgroup} --root "$ROOT" "$@"
}

# Wrapper for runc spec, which takes only one argument (the bundle path).
Expand Down

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