[Bug 1915829] Re: FQDN / hostname recorded in OVSDB is unreliable

[Robie Basak]

** Description changed:

  [ Impact ]
  
  The Open vSwitch init script `ovs-ctl` determines the system hostname
  and records it in the `external-ids:hostname` field of the `Open-
  vSwitch` table in the local OVSDB.
  
  This value may be consumed by downstream software and having it unset or
  set to a incorrect value could lead to erratic behavior of a system.
  
  In recent Ubuntu development we have also made it possible to configure
  Open vSwitch with netplan.io, which allows for a Open vSwitch controlled
  data path to be the only external network connection on a system.
  
  As such the current startup sequence of Open vSwitch is insufficient to
  allow for reliable recording of FQDN / hostname at system boot-up time.
  
  Examples of downstream issues can be viewed in bug 1896630 and bug
  1912844 comment #26.
  
  [ Test Case ]
  
  1) Use MAAS 2.9, configure a machine with Open vSwitch bridge for networking and deploy.
  2) Confirm that without the change the hostname recorded in Open vSwitch is `ubuntu`.
  3) Add a PPA with the updated Open vSwitch package to MAAS.
  4) Re-deploy and confirm that the hostname recorded in Open vSwitch matches the FQDN as provided by MAAS.
  
  [ Regression potential ]
  
  Minimal, the update uses the exact same methods to accomplish the end
  result of recording the hostname as before, we have only re-ordered when
  the events occur to ensure successful operation.
  
+ [racb] A new service is added in packaging. Users who have overridden
+ existing services to change behaviour (eg. "disable all OVS-related
+ services") may have that configuration not have the same effect after
+ this update (eg. "I thought I disabled all OVS-related services but
+ what's this ovs-record-hostname thing now?")
+ 
  [ Other Info ]
  
  A possible solution to this would be to extend the upstream `ovs-ctl`
  script to allow controlling when the hostname is recorded and adding a
  new Systemd service file to the package that calls the `record-hostname`
  function at a more appropriate time, i.e. after or as part of the
  `network-online.target`.
  
  An example of downstream issues can be viewed in bug 1896630.

-- 
You received this bug notification because you are a member of Ubuntu
OpenStack, which is subscribed to openvswitch in Ubuntu.
https://bugs.launchpad.net/bugs/1915829

Title:
  FQDN / hostname recorded in OVSDB is unreliable

Status in Ubuntu Cloud Archive:
  Fix Released
Status in Ubuntu Cloud Archive ussuri series:
  Triaged
Status in Ubuntu Cloud Archive victoria series:
  Triaged
Status in Ubuntu Cloud Archive wallaby series:
  Fix Released
Status in openvswitch package in Ubuntu:
  Fix Released
Status in openvswitch source package in Focal:
  In Progress
Status in openvswitch source package in Groovy:
  In Progress
Status in openvswitch source package in Hirsute:
  Fix Released

Bug description:
  [ Impact ]

  The Open vSwitch init script `ovs-ctl` determines the system hostname
  and records it in the `external-ids:hostname` field of the `Open-
  vSwitch` table in the local OVSDB.

  This value may be consumed by downstream software and having it unset
  or set to a incorrect value could lead to erratic behavior of a
  system.

  In recent Ubuntu development we have also made it possible to
  configure Open vSwitch with netplan.io, which allows for a Open
  vSwitch controlled data path to be the only external network
  connection on a system.

  As such the current startup sequence of Open vSwitch is insufficient
  to allow for reliable recording of FQDN / hostname at system boot-up
  time.

  Examples of downstream issues can be viewed in bug 1896630 and bug
  1912844 comment #26.

  [ Test Case ]

  1) Use MAAS 2.9, configure a machine with Open vSwitch bridge for networking and deploy.
  2) Confirm that without the change the hostname recorded in Open vSwitch is `ubuntu`.
  3) Add a PPA with the updated Open vSwitch package to MAAS.
  4) Re-deploy and confirm that the hostname recorded in Open vSwitch matches the FQDN as provided by MAAS.

  [ Regression potential ]

  Minimal, the update uses the exact same methods to accomplish the end
  result of recording the hostname as before, we have only re-ordered
  when the events occur to ensure successful operation.

  [racb] A new service is added in packaging. Users who have overridden
  existing services to change behaviour (eg. "disable all OVS-related
  services") may have that configuration not have the same effect after
  this update (eg. "I thought I disabled all OVS-related services but
  what's this ovs-record-hostname thing now?")

  [ Other Info ]

  A possible solution to this would be to extend the upstream `ovs-ctl`
  script to allow controlling when the hostname is recorded and adding a
  new Systemd service file to the package that calls the `record-
  hostname` function at a more appropriate time, i.e. after or as part
  of the `network-online.target`.

  An example of downstream issues can be viewed in bug 1896630.

To manage notifications about this bug go to:
https://bugs.launchpad.net/cloud-archive/+bug/1915829/+subscriptions