[ckan-dev] pylons.app_globals vs pylons.config

[Sean Hammond]

>  More generally we have some requirements for the config options
> 
> 1) avoid duplication of code
> 2) document each option where it is defined
> 3) Automatically generate the ckan html config docs
> 4) have default values defined (only once)
> 5) have a type (int, bool etc) so we don't have to keep re-parsing it
> 6) be available to templates
> 7) extensions to be able to add there own options and get any features eg
> parsing
> 8) do some validation of options at ckan start-up - including that it has
> documentation.
> 9) easy ways to deprecate/rename options
> 10) be able to override the file config from the database (allow editable
> options)
> 11) be able to easily add the config options to docs using the `Adriá Hack`
> https://github.com/okfn/ckan/commit/01cd2def9e2be7ffd0afb6de8c96c654b7572a7c(or
> similar)
> 12) define all the core options in one place
> 13) sort the config vs globals issue for consistency
> 14) be documented
> 15)  deployment.ini_tmpl be kept in sync (maybe via some tests)
> 
> 
> At the moment this is a bit adhoc and it would be good to get it cleaned up
> a bit.
> 
> I'm happy to look at this.  There are some general issue like
> 
> Do we define the config options in python ie like currently in
> lib.app_globals or in some other format I prefer the python as it's just
> easier but others may feel different
> 
> Can people see if they are aware of any other requirements around the
> config options

We should have a naming scheme for config options. What characters are
allowed in config option names? Config options should be named so that
options related to the same feature share a substring and therefore sort
next to eachother alphanumerically.

For some configs this is already done, others not.  For example, we
have:

ckan.cache_enabled
ckan.static_max_age
ckan.cache_expires

which are apparently the same feature (or not?), should be something
like:

ckan.cache.enabled
ckan.cache.max_age
ckan.cache.expires

This would probably mean renaming a lot of options.