[mesos] 05/05: Fixed wrong `mnt` namespace detection for non-command executor tasks.

[al...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

alexr pushed a commit to branch 1.7.x
in repository https://gitbox.apache.org/repos/asf/mesos.git

commit eecefa621e3f8a3040439c77939d2c08ed6e18ce
Author: Andrei Budnik <ab...@mesosphere.com>
AuthorDate: Mon Aug 20 16:28:44 2018 +0200

    Fixed wrong `mnt` namespace detection for non-command executor tasks.
    
    Previously, we were calling `getMountNamespaceTarget()` not only in
    case of the command executor but in all other cases too, including
    the default executor. That might lead to various subtle bugs, caused by
    wrong detection of `mnt` namespace target. This patch fixes the issue
    by setting a parent PID as `mnt` namespace target in case of
    non-command executor task.
    
    Review: https://reviews.apache.org/r/68348/
---
 src/slave/containerizer/mesos/containerizer.cpp | 27 +++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/slave/containerizer/mesos/containerizer.cpp b/src/slave/containerizer/mesos/containerizer.cpp
index ba24180..c38bfac 100644
--- a/src/slave/containerizer/mesos/containerizer.cpp
+++ b/src/slave/containerizer/mesos/containerizer.cpp
@@ -1940,20 +1940,31 @@ Future<Containerizer::LaunchResult> MesosContainerizerProcess::_launch(
       return Failure("Unknown parent container");
     }
 
-    if (containers_.at(containerId.parent())->pid.isNone()) {
+    const Owned<Container>& parentContainer =
+      containers_.at(containerId.parent());
+
+    if (parentContainer->pid.isNone()) {
       return Failure("Unknown parent container pid");
     }
 
-    pid_t parentPid = containers_.at(containerId.parent())->pid.get();
+    const pid_t parentPid = parentContainer->pid.get();
 
-    Try<pid_t> mountNamespaceTarget = getMountNamespaceTarget(parentPid);
-    if (mountNamespaceTarget.isError()) {
-      return Failure(
-          "Cannot get target mount namespace from process " +
-          stringify(parentPid) + ": " + mountNamespaceTarget.error());
+    // For the command executor case, we need to find a PID of its task,
+    // which will be used to enter the task's mount namespace.
+    if (parentContainer->config.isSome() &&
+        parentContainer->config->has_task_info()) {
+      Try<pid_t> mountNamespaceTarget = getMountNamespaceTarget(parentPid);
+      if (mountNamespaceTarget.isError()) {
+        return Failure(
+            "Cannot get target mount namespace from process " +
+            stringify(parentPid) + ": " + mountNamespaceTarget.error());
+      }
+
+      launchFlags.namespace_mnt_target = mountNamespaceTarget.get();
+    } else {
+      launchFlags.namespace_mnt_target = parentPid;
     }
 
-    launchFlags.namespace_mnt_target = mountNamespaceTarget.get();
     _enterNamespaces = _enterNamespaces.get() & ~CLONE_NEWNS;
   }
 #endif // __linux__