Allow revisionless cs: urls to be valid and found.

Allow revisionless cs: urls to be valid and found.

- Normally a full qualified store_url has a version on the end. Some users
(Jorge) remove those to create bundles that stay up to date with charms vs
locked.
- This supports that by performing a mongo regex vs exact match query when no
revision is found on the charm store urls.

https://code.launchpad.net/~rharding/charmworld/fix-revisionless-store_url/+merge/193336

(do not edit description out of merge proposal)

[rharding, 2013-10-30 21:05:13]

Please take a look.

[bac, 2013-10-30 21:12:15]

LGTM

https://codereview.appspot.com/19990043/diff/1/charmworld/models.py
File charmworld/models.py (right):

https://codereview.appspot.com/19990043/diff/1/charmworld/models.py#newcode1637
charmworld/models.py:1637: "$regex": charm_description.store_url
Perhaps a comment here explaining why only the most recent revisions is found
due to code elsewhere would be good.

[benji, 2013-10-30 21:12:59]

LGTM once the comments have been considered.

https://codereview.appspot.com/19990043/diff/1/charmworld/models.py
File charmworld/models.py (right):

https://codereview.appspot.com/19990043/diff/1/charmworld/models.py#newcode1630
charmworld/models.py:1630: # That cs url may or may not have a revision in it.
If not, use a
It took me a second to figure out what "cs" was.  That suggests expanding it to
"charmstore" would help a less-involved reader.

https://codereview.appspot.com/19990043/diff/1/charmworld/models.py#newcode1637
charmworld/models.py:1637: "$regex": charm_description.store_url
Do we know that the regex query will return the latest version?

Is there something like a $prefix operator that we could use instead.  If not,
we should meditate upon whether or not a store URL could be interpreted as a
regex.  For example, if a dot were allowed in the name it would match any
character, potentially returning the wrong data.

Once that meditation has been done (or if it has already been done), a comment
noting the potential complications and that they have been considered would be
good.