Do not share container log driver for exec

When the container uses journald logging, we don't want to
automatically use the same driver for its exec sessions. If we do
we will pollute the journal (particularly in the case of
healthchecks) with large amounts of undesired logs. Instead,
force exec sessions logs to file for now; we can add a log-driver
flag later (we'll probably want to add a `podman logs` command
that reads exec session logs at the same time).

As part of this, add support for the new 'none' logs driver in
Conmon. It will be the default log driver for exec sessions, and
can be optionally selected for containers.

Great thanks to Joe Gooch (mrwizard@dok.org) for adding support
to Conmon for a null log driver, and wiring it in here.

Fixes #6555

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 9 insertions, 7 deletions

diff --git a/libpod/oci_conmon_linux.go b/libpod/oci_conmon_linux.go
index 0921a532b..625a5bf70 100644
--- a/libpod/oci_conmon_linux.go
+++ b/libpod/oci_conmon_linux.go
@@ -881,7 +881,7 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co
 		return err
 	}
 
-	args := r.sharedConmonArgs(ctr, ctr.ID(), ctr.bundlePath(), filepath.Join(ctr.state.RunDir, "pidfile"), ctr.LogPath(), r.exitsDir, ociLog, logTag)
+	args := r.sharedConmonArgs(ctr, ctr.ID(), ctr.bundlePath(), filepath.Join(ctr.state.RunDir, "pidfile"), ctr.LogPath(), r.exitsDir, ociLog, ctr.LogDriver(), logTag)
 
 	if ctr.config.Spec.Process.Terminal {
 		args = append(args, "-t")
@@ -1137,7 +1137,7 @@ func (r *ConmonOCIRuntime) configureConmonEnv(runtimeDir string) ([]string, []*o
 }
 
 // sharedConmonArgs takes common arguments for exec and create/restore and formats them for the conmon CLI
-func (r *ConmonOCIRuntime) sharedConmonArgs(ctr *Container, cuuid, bundlePath, pidPath, logPath, exitDir, ociLogPath, logTag string) []string {
+func (r *ConmonOCIRuntime) sharedConmonArgs(ctr *Container, cuuid, bundlePath, pidPath, logPath, exitDir, ociLogPath, logDriver, logTag string) []string {
 	// set the conmon API version to be able to use the correct sync struct keys
 	args := []string{
 		"--api-version", "1",
@@ -1155,12 +1155,14 @@ func (r *ConmonOCIRuntime) sharedConmonArgs(ctr *Container, cuuid, bundlePath, p
 		args = append(args, "-s")
 	}
 
-	var logDriver string
-	switch ctr.LogDriver() {
+	var logDriverArg string
+	switch logDriver {
 	case define.JournaldLogging:
-		logDriver = define.JournaldLogging
+		logDriverArg = define.JournaldLogging
 	case define.JSONLogging:
 		fallthrough
+	case define.NoLogging:
+		logDriverArg = define.NoLogging
 	default: //nolint-stylecheck
 		// No case here should happen except JSONLogging, but keep this here in case the options are extended
 		logrus.Errorf("%s logging specified but not supported. Choosing k8s-file logging instead", ctr.LogDriver())
@@ -1170,10 +1172,10 @@ func (r *ConmonOCIRuntime) sharedConmonArgs(ctr *Container, cuuid, bundlePath, p
 		// since the former case is obscure, and the latter case isn't an error, let's silently fallthrough
 		fallthrough
 	case define.KubernetesLogging:
-		logDriver = fmt.Sprintf("%s:%s", define.KubernetesLogging, logPath)
+		logDriverArg = fmt.Sprintf("%s:%s", define.KubernetesLogging, logPath)
 	}
 
-	args = append(args, "-l", logDriver)
+	args = append(args, "-l", logDriverArg)
 	if r.logSizeMax >= 0 {
 		args = append(args, "--log-size-max", fmt.Sprintf("%v", r.logSizeMax))
 	}