[COUCHDB-1046] support load of external erlang modules in couchdb.

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: Database Core
• Skill Level: Regular Contributors Level (Easy to Medium)
• Assignee: Unassigned
• Reporter: Benoit Chesneau
• Created: 27/Jan/11 16:03
• Updated: 02/Sep/18 06:31
• Resolved: 02/Sep/18 06:31

Description

If you want to add external modules in CouchDB and load them , you need to set the ERL_FLAGS environnement variable to the path of a module.

The attached patch allows couchdb to load plugins from plugin key in couchdb section. It add needed path to the code path, so the vm can find modules.

ex:
[couchdb]
plugins = plugin1, plugin2

Each plugin can have its own section where it set the binaries patch, eventually if a service need to be added to the supervision you can set the module and function to load like in daemon section and tel if it's a supervisor or simple service.

It also allows couchdb to load a plugin service (gen_server or such) to the supervision. You can choose if the service is a simple daemon or a supervisor.

ex:
[plugin1]
code_path = /path/to/plugin1/ebin
daemon =

{module, function, [Args]}

supervisor = false

Let me know what you think about it. This patch is really useful here and allows me to dynamically load modules I want. Also it eases the integration of external module. For ex I can load my couchapp_ng modules with this lines in local.ini :

[couchdb]
plugins = couchapp-ng

[couchapp-ng]
code_path=/Users/benoitc/work/couchapp_ng/ebin
daemon =

{couchapp_ng_routes, start_link, []}

[httpd_design_handlers]
_app =

{couchapp_ng_httpd, handle_app_req}

[couchapp_ng_handlers]
rewrite =

{couchapp_ng_handlers, rewrite_handler}

proxy =

{couchapp_ng_handlers, proxy_handler}

and can do the same with geocouch etc. Tested here with these modules.