[Bug 1713537] Re: iscsi-targets don't quit session on shutdown

[Scott Moser]

When I first saw this, I assumed that it was a result of ifupdown being
dropped from the image (bug 1698181).  However, it seems (as of the
20170826 cloud image) that that has not yet happened.

Additionally, I've not been able to reproduce this with the dep8 tests
that are in open-iscsi.  And those tests *do* a boot and shutdown
on a iscsi target root.

In an effort to describe what happened previously in zesty and how that
might have gone wrong, I wrote the info below.

In iscsi root environment, the initrams brings up the network connection,
and then connects to the iscsi target.  It has to communicate with the target
root in order to acheive the following things:

  a. make the network device not be bounced on the re-played coldplug after
     pivot.
  b. do not take the network device *down* on shutdown.
  c. update DNS information from the result of a dhcp or other network
     configuration.

Artful dropped ifupdown, so the methods which were present in xenial-zesty
to accomplish those things have broken.
I suspect it is possible that 'a' and 'b' can be accomplished by somehow
informing systemd that the root mount was a '_netdev' (mount -O _netdev).
An untested patch for this might look like:
  http://paste.ubuntu.com/25418884/

Its possible that resolvconf integration will still work.

iscsi root works in xenial -> zesty like this:
 * in its local-top [1] initramfs hooks, open-iscsi writes the interface
   that the root device lives on to /run/initramfs/open-iscsi.interface.
 * on interface add (coldplug) or remove (shutdown)
   udev rules /lib/udev/rules.d/70-iscsi-network-interface.rules [2]
   call /lib/open-iscsi/net-interface-handler [3].
 * net-interface-handler is then responsible for basically mocking the
   interface up and interface down for the root network device.  This 
   includes all of 'a', 'b', and 'c'.
   For dns configuration, see the lines around 'command -v resolvconf' at [3].

[1] https://git.launchpad.net/~usd-import-team/ubuntu/+source/open-iscsi/tree/debian/extra/initramfs.local-top?h=applied/ubuntu/zesty
[2] https://git.launchpad.net/~usd-import-team/ubuntu/+source/open-iscsi/tree/debian/iscsi-network-interface.rules?h=applied/ubuntu/zesty
[3] https://git.launchpad.net/~usd-import-team/ubuntu/+source/open-iscsi/tree/debian/net-interface-handler?h=applied/ubuntu/zesty

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to open-iscsi in Ubuntu.
https://bugs.launchpad.net/bugs/1713537

Title:
  iscsi-targets don't quit session on shutdown

Status in open-iscsi package in Ubuntu:
  New

Bug description:
  1. Artful (MAAS Image)[a]
  2. open-iscsi	2.0.874-4ubuntu1
  3. On shutdown, all iscsi sessions to be stopped and unmounted
  4. Iscsi stops but does not stop sessions and shutdown is blocked/hung

  [^[[0;32m  OK  ^[[0m] Reached target Shutdown.
  [  125.666350]  connection4:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4294921130, last ping 4294922432, now 4294923712
  [  125.922334]  connection3:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4294921211, last ping 4294922496, now 4294923776
  [  126.178553]  connection2:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4294921292, last ping 4294922560, now 4294923840
  [  126.434334]  connection1:0: ping timeout of 5 secs expired, recv timeout 5, last rx 4294921371, last ping 4294922624, now 4294923904

  Note, previously released Artful MAAS images work fine:
  http://images.maas.io/ephemeral-v2/daily/artful/amd64/20170721/
  which contain 

  open-iscsi      2.0.873+git0.3b4b4500-14ubuntu17

  a. http://images.maas.io/ephemeral-v2/daily/artful/amd64/20170826/

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/open-iscsi/+bug/1713537/+subscriptions