race condition in charm upload

[Jason Hobbs]

I have a test that creates many applications from a local charm. In parallel, i have 5 threads running that do:

for i in x to y:
   juju deploy ./small-charm small{$i}

The charms all have the same name and get assigned a full name like "local:xenial/small-charm-999", the number being dependent on the order the charm gets uploaded.

Sometimes I'll get an error:
ERROR cannot upload charm: already exists

I guess more than one upload is trying to claim the same name - looks like a race condition.

This is with juju2.1-beta3

[Anastasia (anastasia-macmood)]

Removing 2.1 milestone as we will not be addressing this issue in 2.1.

[Paul Gear (paulgear)]

This can also occur during charm upgrades. Retrying the upgrade usually works:

[master*]paulgear@peleg:/srv/branches/canonical-livepatch-charm$ juju upgrade-charm --path $JUJU_REPOSITORY/builds/canonical-livepatch canonical-livepatch
ERROR cannot upload charm: already exists
[master*]paulgear@peleg:/srv/branches/canonical-livepatch-charm$ juju upgrade-charm --path $JUJU_REPOSITORY/builds/canonical-livepatch canonical-livepatch
Added charm "local:xenial/canonical-livepatch-1" to the model.

[Paul Collins (pjdc)]

I ran into this today with a couple of 2.4.3 controllers, e.g.:

(juju2-jaas-azure-westeurope-001)prodstack-cdo@wekufe:~$ juju upgrade-charm --path /srv/mojo/$MOJO_PROJECT/$MOJO_SERIES/$MOJO_WORKSPACE/charms/$MOJO_SERIES/nrpe nrpe
ERROR cannot upload charm: already exists
(juju2-jaas-azure-westeurope-001)prodstack-cdo@wekufe:~$ juju upgrade-charm --path /srv/mojo/$MOJO_PROJECT/$MOJO_SERIES/$MOJO_WORKSPACE/charms/$MOJO_SERIES/nrpe nrpe
Added charm "local:xenial/nrpe-1" to the model.
(juju2-jaas-azure-westeurope-001)prodstack-cdo@wekufe:~$ _

[Junien F (axino)]

controller logs on the ERROR, as per bug 1805990

2018-11-30 08:21:22 ERROR juju.apiserver charms.go:479 returning error from POST /model/<uuid>/charms?%3Amodeluuid=<uuid>&revision=0&schema=local&series=xenial: [{github.com/juju/juju/apiserver/charms.go:69: } {github.com/juju/juju/apiserver/charms.go:61: cannot upload charm} {github.com/juju/juju/apiserver/charms.go:104: } {github.com/juju/juju/apiserver/charms.go:256: } {github.com/juju/juju/state/charm.go:678: } {github.com/juju/juju/state/charm.go:169: already exists}]

[Junien F (axino)]

This bug is still present on 2.4.5.

[Canonical Juju QA Bot (juju-qa-bot)]

This bug has not been updated in 2 years, so we're marking it Low importance. If you believe this is incorrect, please update the importance.