node-couchs

Follow.js based, bare-naked couchdb change stream to stdout.

Installation

  $ git clone https://github.com/snbartell/node-couchs.git
  $ cd node-couchs; npm install

Usage

  $ couchs -h
  usage:     couchs [options] [db]

  db:        path to database (optional when using env vars.)

  options:
     -v      show options
     -h      youre staring at it
     -id     filter this id (uses built-in filter)

  environment variables: 
     db,       path to database
     since,    "since" query param. since="now" is last checkpoint
     filter,   dynamic client-side filter.
     delim ,   document delimiter

Environment Variables

use the env

    export db="http://localhost:5984/mydb"
    export delim='\r\n\n'

then

  $ couchs

Use with node-jsdiff

The only reason I made couchs is to have something to pump a couch change stream into a json-differ.

Something like this:

    {
        transports: [
            [
                {
                    type: 'mongo',
                    active: true,
                    id: 'mongolog',
                    filter: { infoOnly: 'function(message){}' },
                    collection: 'log',
                    port: 27017,
                    database: 'log',
                    host: 'localhost'
                }
            ]
        ],
        active: [ true ],
        channel: [ 'log' ],
        _id: [ 'loggerjs.config' ],
        port: [ 6379 ],
        _rev: [ '90-0d0125d81e7aa982e7fffbad2efe6c31' ],
        host: [ 'localhost' ]
    }
    {
        _rev: [ '90-0d0125d81e7aa982e7fffbad2efe6c31', '91-7e6f3df88c7085b8433c281d91313c65' ]
    }
    {
        _rev: [ '91-7e6f3df88c7085b8433c281d91313c65', '92-a8dfbb16601126f7b0a1d84bd79b3b52' ]
    }
    {
        transports: {
            0: {
                active: [ true, false ]
            },
            _t: 'a'
        },
        _rev: [ '92-a8dfbb16601126f7b0a1d84bd79b3b52', '93-8c43ee44b87ae007d725802ed0015fc7' ]
    }

There are four changes here.

1. The first change is shown as a full document. Reason is becuase it is diffed against and empty json doc {}

2. The second change shows the _rev changed from 90-0... to 91-7....

3. The third change is telling me the revision bumped again.

4. The fourth change is saying that the rev bumped and the first item in the transports list had property active go from true to false. Dont mind the _t, its a hidden property.

So heres how to do it:

install jsdiff:

    git clone https://github.com/snbartell/node-jsondiff.git
    cd node-jsdiff
    npm link

couchs and jsdiff work together when they both know the same document delimiter. jsdiff expects the delim to be \r\n\n\n. So set the couchs env var for delim:

    export delim='\r\n\n\n'

You can give the database path as an arg to couchs, or set the db env var. I like to set env vars.

    export db="http://user:pass@localhost:5984/database" 

... or something like that

Finally, pipe couchs into jsdiff:

    couchs | jsdiff