Pyroute2 netns.ns_pids() will fail if during the function loop, one namespace is deleted

[Rodolfo Alonso]

Log: https://2af908e1173c237cb5bf-b484a2b89d5d2c358f068133dfb2fa14.ssl.cf2.rackcdn.com/678905/1/check/neutron-functional/9770e53/testr_results.html.gz

If during the namepace PIDs retrieval one of those namespaces is deleted, the method [1] will fail with the exception:
  FileNotFoundError: [Errno 2] No such file or directory

[1] https://github.com/svinota/pyroute2/blob/b25a6ca6c91da45cb5b54e7caffa1644fed2330d/pyroute2/netns/__init__.py#L163

[Rodolfo Alonso (rodolfo-alonso-hernandez)]

Submitted an issue in Pyroute2: https://github.com/svinota/pyroute2/issues/633

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/679026

[OpenStack Infra (hudson-openstack)]

Change abandoned by Rodolfo Alonso Hernandez (<email address hidden>) on branch: master
Review: https://review.opendev.org/679026
Reason: This workaround now can trigger a timeout exception... [1]

I'll try a better solution, implementing inside Neutron the method to read the namespace PIDs.

[1] https://storage.gra1.cloud.ovh.net/v1/AUTH_dcaab5e32b234d56b626f72581e3644c/logs_26/679026/4/gate/neutron-functional-python27/27c64b1/testr_results.html.gz

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/679428

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/679428
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=085e9d8b3de44a6edd71f2de7e9c2acde053b331
Submitter: Zuul
Branch: master

commit 085e9d8b3de44a6edd71f2de7e9c2acde053b331
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Fri Aug 30 12:09:45 2019 +0000

    Implement "list_ns_pids" inside Neutron

    Instead of using Pyroute2.netns.ns_pids() [1], while [2] is not
    solved, a method to list a namespace PIDs is implemented in this
    patch.

    This implementation is based on the Pyroute2 method.

    [1]https://github.com/svinota/pyroute2/blob/80f6e7fcdd4136933a7f164ba2cee25f134dc85c/pyroute2/netns/__init__.py#L163
    [2]https://github.com/svinota/pyroute2/issues/633

    Change-Id: Ic00c02035a0dabf1a1efd1995c84692649c6ad27
    Related-Bug: #1841753

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/692396

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/692396
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=9ad03dcf96b9b2fbe43dede8b59c99542bda237a
Submitter: Zuul
Branch: master

commit 9ad03dcf96b9b2fbe43dede8b59c99542bda237a
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Thu Oct 31 15:32:09 2019 +0000

    Catch FileNotFoundError when listing namespace PIDs

    During the namespace PID listing, if a process is stopped, it will
    disappear from "/proc/<pid>". When "os.stat(path)" is executed on
    an unexistent path, returns "FileNotFoundError". This exception
    should be catched and ignored.

    Change-Id: Icde5e15bd97578f5ec8273f22ef8384502be1850
    Related-Bug: #1841753

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: stable/stein
Review: https://review.opendev.org/718227

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/718227
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=bf05b63f1b102b3bedde1c637d272982d8d4813a
Submitter: Zuul
Branch: stable/stein

commit bf05b63f1b102b3bedde1c637d272982d8d4813a
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Fri Aug 30 12:09:45 2019 +0000

    Implement "list_ns_pids" inside Neutron

    Instead of using Pyroute2.netns.ns_pids() [1], while [2] is not
    solved, a method to list a namespace PIDs is implemented in this
    patch.

    This implementation is based on the Pyroute2 method.

    [1]https://github.com/svinota/pyroute2/blob/80f6e7fcdd4136933a7f164ba2cee25f134dc85c/pyroute2/netns/__init__.py#L163
    [2]https://github.com/svinota/pyroute2/issues/633

    Conflicts:
        neutron/privileged/agent/linux/ip_lib.py

    Change-Id: Ic00c02035a0dabf1a1efd1995c84692649c6ad27
    Related-Bug: #1841753
    (cherry picked from commit 085e9d8b3de44a6edd71f2de7e9c2acde053b331)