state: Generalise error handling when splitting logs collection

[mjs]

Description of change

The error checks in SplitLogCollections didn't work on MongoDB 2.4 as
older MongoDB versions only return an error string without the error
code.

mgo's IsDup helper is now used for insert error handling and "ns not
found" is now checked by code or string.

Fixes https://bugs.launchpad.net/juju/+bug/1701999

QA steps

Related unit tests were failing on MongoDB 2.4 before and pass now.

Documentation changes

N.A.

Bug reference

https://bugs.launchpad.net/juju/+bug/1701999

[babbageclunk]

Good spotting.

[mjs]

$$merge$$

[jujubot]

Status: merge request accepted. Url: http://juju-ci.vapour.ws:8080/job/github-merge-juju

[jameinel]

Off-hand, shouldn't we have a a name for the error code instead of just a number mgo.NamespaceNotFoundCode or somesuch?

[mjs]

No such constant exists in the mgo package. Is that what you mean?

[jameinel]

I mean that something like '26' should definitely be pulled into a constant. Having it in 'mgo' would be ideal, but if not there, we should have our own. Its somewhat ok that we're at least using a helper (isMgoNamespaceNotFound), but it still feels very odd to not have the collection of error codes somewhere.

…

On Mon, Jul 3, 2017 at 1:12 PM, Menno Smits ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In state/upgrades.go <#7588 (comment)>: > } return errors.Annotate(err, "failed to drop old logs collection") } return nil } +func isMgoNamespaceNotFound(err error) bool { + // Check for &mgo.QueryError{Code:26, Message:"ns not found"} + if qerr, ok := err.(*mgo.QueryError); ok { + if qerr.Code == 26 { No such constant exists in the mgo package. Is that what you mean? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#7588 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAMYfePSD2Yf_iy3tTk6fjPOnuR0SwpBks5sKLCEgaJpZM4OL1dY> .