Fall back to podman logs when journalctl is inaccessible

Probe journalctl with -n 0 before committing to it. When the journal
is not readable (e.g. rootless podman without user journal storage),
fall back to podman logs instead of streaming the permission error.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/runtime/podman.go

@@ -180,36 +180,33 @@ func (p *Podman) Inspect(ctx context.Context, name string) (ContainerInfo, error
 }
 
 // Logs returns an exec.Cmd that streams container logs. For containers
-// using the journald log driver, it uses journalctl (podman logs can't
+// using the journald log driver, it tries journalctl first (podman logs
-// read journald outside the originating user session). For k8s-file or
+// can't read journald outside the originating user session). If journalctl
-// other drivers, it uses podman logs directly.
+// can't access the journal, it falls back to podman logs.
 func (p *Podman) Logs(ctx context.Context, containerName string, tail int, follow, timestamps bool, since string) *exec.Cmd {
 	// Check if this container uses the journald log driver.
 	inspectCmd := exec.CommandContext(ctx, p.command(), "inspect", "--format", "{{.HostConfig.LogConfig.Type}}", containerName) //nolint:gosec
 	if out, err := inspectCmd.Output(); err == nil && strings.TrimSpace(string(out)) == "journald" {
+		if p.journalAccessible(ctx, containerName) {
 			return p.journalLogs(ctx, containerName, tail, follow, since)
 		}
+	}
 
-	args := []string{"logs"}
+	return p.podmanLogs(ctx, containerName, tail, follow, timestamps, since)
-	if tail > 0 {
+}
-		args = append(args, "--tail", fmt.Sprintf("%d", tail))
+
+// journalAccessible probes whether journalctl can read logs for the container.
+func (p *Podman) journalAccessible(ctx context.Context, containerName string) bool {
+	args := []string{"--no-pager", "-n", "0"}
+	if os.Getuid() != 0 {
+		args = append(args, "--user")
 	}
-	if follow {
+	args = append(args, "CONTAINER_NAME="+containerName)
-		args = append(args, "--follow")
+	cmd := exec.CommandContext(ctx, "journalctl", args...) //nolint:gosec
-	}
+	return cmd.Run() == nil
-	if timestamps {
-		args = append(args, "--timestamps")
-	}
-	if since != "" {
-		args = append(args, "--since", since)
-	}
-	args = append(args, containerName)
-	return exec.CommandContext(ctx, p.command(), args...) //nolint:gosec // args built programmatically
 }
 
 // journalLogs returns a journalctl command filtered by container name.
-// For rootless podman, container logs go to the user journal, so we
-// need --user to read them.
 func (p *Podman) journalLogs(ctx context.Context, containerName string, tail int, follow bool, since string) *exec.Cmd {
 	args := []string{"--no-pager", "--output", "cat"}
 	if os.Getuid() != 0 {
@@ -228,6 +225,25 @@ func (p *Podman) journalLogs(ctx context.Context, containerName string, tail int
 	return exec.CommandContext(ctx, "journalctl", args...) //nolint:gosec // args built programmatically
 }
 
+// podmanLogs returns a podman logs command.
+func (p *Podman) podmanLogs(ctx context.Context, containerName string, tail int, follow, timestamps bool, since string) *exec.Cmd {
+	args := []string{"logs"}
+	if tail > 0 {
+		args = append(args, "--tail", fmt.Sprintf("%d", tail))
+	}
+	if follow {
+		args = append(args, "--follow")
+	}
+	if timestamps {
+		args = append(args, "--timestamps")
+	}
+	if since != "" {
+		args = append(args, "--since", since)
+	}
+	args = append(args, containerName)
+	return exec.CommandContext(ctx, p.command(), args...) //nolint:gosec // args built programmatically
+}
+
 // Login authenticates to a container registry using the given token as
 // the password. This enables non-interactive push with service account
 // tokens (MCR accepts MCIAS JWTs as passwords).