libpod: wait for healthy on main thread

wait for the healthy status on the thread where the container lock is
held.  Otherwise, if it is performed from a go routine, a different
thread is used (since the runtime.LockOSThread() call doesn't have any
effect), causing pthread_mutex_unlock() to fail with EPERM.

Closes: containers#22651

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

Author: giuseppe

libpod/container_api.go

@@ -115,7 +115,10 @@ func (c *Container) Start(ctx context.Context, recursive bool) (finalErr error)
 	}
 
 	// Start the container
-	return c.start(ctx)
+	if err := c.start(); err != nil {
+		return err
+	}
+	return c.waitForHealthy(ctx)
 }
 
 // Update updates the given container.
@@ -194,6 +197,9 @@ func (c *Container) StartAndAttach(ctx context.Context, streams *define.AttachSt
 		opts.Start = true
 		opts.Started = startedChan
 
+		// attach and start the container on a different thread.  waitForHealthy must
+		// be done later, as it requires to run on the same thread that holds the lock
+		// for the container.
 		if err := c.ociRuntime.Attach(c, opts); err != nil {
 			attachChan <- err
 		}
@@ -207,7 +213,7 @@ func (c *Container) StartAndAttach(ctx context.Context, streams *define.AttachSt
 		c.newContainerEvent(events.Attach)
 	}
 
-	return attachChan, nil
+	return attachChan, c.waitForHealthy(ctx)
 }
 
 // RestartWithTimeout restarts a running container and takes a given timeout in uint

libpod/container_internal.go

@@ -330,10 +330,10 @@ func (c *Container) handleRestartPolicy(ctx context.Context) (_ bool, retErr err
 			return false, err
 		}
 	}
-	if err := c.start(ctx); err != nil {
+	if err := c.start(); err != nil {
 		return false, err
 	}
-	return true, nil
+	return true, c.waitForHealthy(ctx)
 }
 
 // Ensure that the container is in a specific state or state.
@@ -1208,7 +1208,7 @@ func (c *Container) reinit(ctx context.Context, retainRetries bool) error {
 
 // Initialize (if necessary) and start a container
 // Performs all necessary steps to start a container that is not running
-// Does not lock or check validity
+// Does not lock or check validity, requires to run on the same thread that holds the lock for the container.
 func (c *Container) initAndStart(ctx context.Context) (retErr error) {
 	// If we are ContainerStateUnknown, throw an error
 	if c.state.State == define.ContainerStateUnknown {
@@ -1253,11 +1253,14 @@ func (c *Container) initAndStart(ctx context.Context) (retErr error) {
 	}
 
 	// Now start the container
-	return c.start(ctx)
+	if err := c.start(); err != nil {
+		return err
+	}
+	return c.waitForHealthy(ctx)
 }
 
 // Internal, non-locking function to start a container
-func (c *Container) start(ctx context.Context) error {
+func (c *Container) start() error {
 	if c.config.Spec.Process != nil {
 		logrus.Debugf("Starting container %s with command %v", c.ID(), c.config.Spec.Process.Args)
 	}
@@ -1298,10 +1301,14 @@ func (c *Container) start(ctx context.Context) error {
 
 	c.newContainerEvent(events.Start)
 
-	if err := c.save(); err != nil {
-		return err
-	}
+	return c.save()
+}
 
+// waitForHealthy, when sdNotifyMode == SdNotifyModeHealthy, waits up to the DefaultWaitInterval
+// for the container to get into the healthy state and reports the status to the notify socket.
+// The function unlocks the container lock, so it must be called from the same thread that locks
+// the container.
+func (c *Container) waitForHealthy(ctx context.Context) error {
 	if c.config.SdNotifyMode != define.SdNotifyModeHealthy {
 		return nil
 	}
@@ -1315,6 +1322,9 @@ func (c *Container) start(ctx context.Context) error {
 	}
 
 	if _, err := c.WaitForConditionWithInterval(ctx, DefaultWaitInterval, define.HealthCheckHealthy); err != nil {
+		if errors.Is(err, define.ErrNoSuchCtr) {
+			return nil
+		}
 		return err
 	}
 
@@ -1566,6 +1576,7 @@ func (c *Container) unpause() error {
 }
 
 // Internal, non-locking function to restart a container
+// It requires to run on the same thread that holds the lock.
 func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (retErr error) {
 	if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateCreated, define.ContainerStateRunning, define.ContainerStateStopped, define.ContainerStateExited) {
 		return fmt.Errorf("unable to restart a container in a paused or unknown state: %w", define.ErrCtrStateInvalid)
@@ -1613,7 +1624,10 @@ func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (retEr
 			return err
 		}
 	}
-	return c.start(ctx)
+	if err := c.start(); err != nil {
+		return err
+	}
+	return c.waitForHealthy(ctx)
 }
 
 // mountStorage sets up the container's root filesystem

libpod/oci_conmon_attach_common.go

@@ -3,7 +3,6 @@
 package libpod
 
 import (
-	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -32,6 +31,7 @@ const (
 // Attach to the given container.
 // Does not check if state is appropriate.
 // started is only required if startContainer is true.
+// It does not wait for the container to be healthy, it is the caller responsibility to do so.
 func (r *ConmonOCIRuntime) Attach(c *Container, params *AttachOptions) error {
 	passthrough := c.LogDriver() == define.PassthroughLogging || c.LogDriver() == define.PassthroughTTYLogging
 
@@ -86,7 +86,7 @@ func (r *ConmonOCIRuntime) Attach(c *Container, params *AttachOptions) error {
 	// If starting was requested, start the container and notify when that's
 	// done.
 	if params.Start {
-		if err := c.start(context.TODO()); err != nil {
+		if err := c.start(); err != nil {
 			return err
 		}
 		params.Started <- true

pkg/domain/infra/abi/containers.go

@@ -995,7 +995,10 @@ func (ic *ContainerEngine) ContainerStart(ctx context.Context, namesOrIds []stri
 				return reports, fmt.Errorf("unable to start container %s: %w", ctr.ID(), err)
 			}
 
-			exitCode = ic.GetContainerExitCode(ctx, ctr.Container)
+			exitCode, err2 := ic.ContainerWaitForExitCode(ctx, ctr.Container)
+			if err2 != nil {
+				logrus.Errorf("Waiting for container %s: %v", ctr.ID(), err2)
+			}
 			reports = append(reports, &entities.ContainerStartReport{
 				Id:       ctr.ID(),
 				RawInput: ctr.rawInput,
@@ -1189,7 +1192,7 @@ func (ic *ContainerEngine) ContainerRun(ctx context.Context, opts entities.Conta
 		report.ExitCode = define.ExitCode(err)
 		return &report, err
 	}
-	report.ExitCode = ic.GetContainerExitCode(ctx, ctr)
+	report.ExitCode, _ = ic.ContainerWaitForExitCode(ctx, ctr)
 	if opts.Rm && !ctr.ShouldRestart(ctx) {
 		if err := removeContainer(ctr, false); err != nil {
 			if errors.Is(err, define.ErrNoSuchCtr) ||
@@ -1203,14 +1206,13 @@ func (ic *ContainerEngine) ContainerRun(ctx context.Context, opts entities.Conta
 	return &report, nil
 }
 
-func (ic *ContainerEngine) GetContainerExitCode(ctx context.Context, ctr *libpod.Container) int {
+func (ic *ContainerEngine) ContainerWaitForExitCode(ctx context.Context, ctr *libpod.Container) (int, error) {
 	exitCode, err := ctr.Wait(ctx)
 	if err != nil {
-		logrus.Errorf("Waiting for container %s: %v", ctr.ID(), err)
 		intExitCode := int(define.ExecErrorCodeNotFound)
-		return intExitCode
+		return intExitCode, err
 	}
-	return int(exitCode)
+	return int(exitCode), nil
 }
 
 func (ic *ContainerEngine) ContainerLogs(ctx context.Context, namesOrIds []string, options entities.ContainerLogsOptions) error {

test/system/260-sdnotify.bats

@@ -233,6 +233,15 @@ READY=1" "Container log after healthcheck run"
     is "$output" "running" "make sure container is still running"
 
     run_podman rm -f -t0 $ctr
+
+    ctr=$(random_string)
+    run_podman run --name $ctr                       \
+            --health-cmd="touch /terminate"          \
+            --sdnotify=healthy                       \
+            $IMAGE sh -c 'while test \! -e /terminate; do sleep 0.1; done; echo finished'
+    is "$output" "finished" "make sure container exited successfully"
+    run_podman rm -f -t0 $ctr
+
     _stop_socat
 }