Add CORS to CouchDB 
Summary
CouchDB doesn't come with CORS enabled by default. This is a problem for libraries like PouchDB, which depend on being able to access CouchDB no matter what URL it's being served from. This script fixes that.
Usage
You need to have Node.js and NPM installed. Then do:
npm install -g add-cors-to-couchdb
add-cors-to-couchdb
Or if it is a remote database:
add-cors-to-couchdb http://me.iriscouch.com -u myusername -p mypassword
Ubuntu - special instructions
On Ubuntu the default Node.js library is called nodejs instead of node due to a naming conflict. To run on Ubuntu, you'll need to do:
sudo apt-get install nodejs-legacy
What it does
This script will simply add some generic CORS configuration to your CouchDB. You could also do it yourself trivially using curl:
HOST=http://adminname:password@localhost:5984 # or whatever you got
curl -X PUT $HOST/_config/httpd/enable_cors -d '"true"'
curl -X PUT $HOST/_config/cors/origins -d '"*"'
curl -X PUT $HOST/_config/cors/credentials -d '"true"'
curl -X PUT $HOST/_config/cors/methods -d '"GET, PUT, POST, HEAD, DELETE"'
curl -X PUT $HOST/_config/cors/headers -d '"accept, authorization, content-type, origin, referer, x-csrf-token"'You can always change the configuration later by simply going to http://localhost:5984/_utils/config.html and updating the values. However, these default options are good for getting up and running.
CouchDB 2.0+ instructions
This modules automatically detects CouchDB 2.0 and should do the right thing. But in case you need to configure CORS on a per-node basis, do:
curl -X GET $HOST/_membershipto see the list of available nodes, then do e.g.:
curl -X PUT $HOST/_node/[email protected]/_config/httpd/enable_cors -d '"true"'
curl -X PUT $HOST/_node/[email protected]/_config/cors/origins -d '"*"'
curl -X PUT $HOST/_node/[email protected]/_config/cors/credentials -d '"true"'
curl -X PUT $HOST/_node/[email protected]/_config/cors/methods -d '"GET, PUT, POST, HEAD, DELETE"'
curl -X PUT $HOST/_node/[email protected]/_config/cors/headers -d '"accept, authorization, content-type, origin, referer, x-csrf-token"'