Specification of branches/hashes/.. #532
Description
Feedback appreciated: @yaswant , @MatthewHambley , @Pierre-siddall , @t00sa , @jasonjunweilyu , @cameronbateman-mo
While atm the versioning steps and commands take a revision parameter (which is interpreted by the underlying tools, e.g. git will take a hash or branch, ...), I wonder if it's worth to support in Fab a common syntax to specify a revision with command line parameter.
The UM needs 5 additional repositories (shumlib, ukca, jules, socrates, casim). If we would have two different command line parameters (one for the URL, one optional for the revision), that's a lot of 'work' (in case of typing required for the command line, and adding the command line parameters etc). We could instead say that a revision is specified by appending @revision at the end of the source URL.
While this can easily be done by an application, my feeling is that this would result in a lot of duplicated code (and the risk of inconsistencies, since an app might decide to do things differently). Instead of leaving it to the apps, the versioning steps could analyse the src (if no explicit revision is given of course), and split off the @ part and pass this as revision to the underlying tool
This would potentially make user scripts shorter, and more consistent.
Note: the usage of '@' at the end need to be investigated, since e.g. a git URL can also have an '@' in them. We need to make sure that it's indeed possible to correctly distinguish between them, e,g, [email protected]:MetOffice/url (no revision specified) and https://.../url@revision (where revision could be a branch, hash, revision number). If that is too complicated, we can use a different character of course.