Store image URLs without server name.

[kmuw]

When migrating a server or changing the hostname, the contents of the postgis database needs a lot of rewriting, e.g.

table public.command (possibly more tables are affected)

{"preview":"http://cytomine.local/api/abstractimage/123/thumb.png?maxSize=1024","thumb":"http://cytomine.local/api/abstractimage/123/thumb.png?maxSize=512","m
acroURL":"http://cytomine.local/ ...

Possible solution:

• save only a global reference to the target host e.g. http://cytomine.local in another table
• provide a migration tool (I did this with pg_dump in plaintext & sed, followed by re-importing the whole database)

[jgillardcytomine]

Dear @kmuw thanks for the feedback.
It is indeed a tight coupling dependency that slows many deployments workflows. Having static full URLs in the database is something that should be avoided.
That change implies a deep refactoring, I'll keep commenting this issue if any step towards it is made.