Offical Apache CouchDB library for Node.js.
Features:
- Minimalistic - There is only a minimum of abstraction between you and CouchDB.
- Pipes - Proxy requests from CouchDB directly to your end user.
- Errors - Errors are proxied directly from CouchDB: if you know CouchDB
you already know
nano
.
- Install npm
npm install nano
or save nano
as a dependency of your project with
npm install --save nano
- Getting started
- Tutorials & screencasts
- Configuration
- Database functions
- nano.db.create(name, [callback])
- nano.db.get(name, [callback])
- nano.db.destroy(name, [callback])
- nano.db.list([callback])
- nano.db.compact(name, [designname], [callback])
- nano.db.replicate(source, target, [opts], [callback])
- nano.db.replication.enable(source, target, [opts], [callback])
- nano.db.replication.query(id, [opts], [callback])
- nano.db.replication.disable(id, [opts], [callback])
- nano.db.changes(name, [params], [callback])
- nano.db.follow(name, [params], [callback])
- nano.db.info([callback])
- nano.use(name)
- nano.request(opts, [callback])
- nano.config
- nano.updates([params], [callback])
- nano.followUpdates([params], [callback])
- Document functions
- db.insert(doc, [params], [callback])
- db.destroy(docname, rev, [callback])
- db.get(docname, [params], [callback])
- db.head(docname, [callback])
- db.copy(src_doc, dest_doc, opts, [callback])
- db.bulk(docs, [params], [callback])
- db.list([params], [callback])
- db.fetch(docnames, [params], [callback])
- db.fetchRevs(docnames, [params], [callback])
- db.createIndex(indexDef, [callback])
- Multipart functions
- Attachments functions
- Views and design functions
- Using cookie authentication
- Advanced features
- Tests
- Release
To use nano
you need to connect it to your CouchDB install, to do that:
var nano = require('nano')('http://localhost:5984');
The URL you supply may also contain authenication credentials e.g. http://admin:mypassword@localhost:5984
.
To create a new database:
nano.db.create('alice');
and to use an existing database:
var alice = nano.db.use('alice');
In this examples we didn't specify a callback
function, the absence of a
callback means "do this, ignore what happens".
In nano
the callback function receives always three arguments:
err
- The error, if any.body
- The HTTP response body from CouchDB, if no error. JSON parsed body, binary for non JSON responses.header
- The HTTP response header from CouchDB, if no error.
A simple but complete example using callbacks is:
var nano = require('nano')('http://localhost:5984');
// clean up the database we created previously
nano.db.destroy('alice', function() {
// create a new database
nano.db.create('alice', function() {
// specify the database we are going to use
var alice = nano.use('alice');
// and insert a document in it
alice.insert({ happy: true }, 'rabbit', function(err, body, header) {
if (err) {
console.log('[alice.insert] ', err.message);
return;
}
console.log('you have inserted the rabbit.')
console.log(body);
});
});
});
If you run this example (after starting CouchDB) you will see:
you have inserted the rabbit.
{ ok: true,
id: 'rabbit',
rev: '1-6e4cb465d49c0368ac3946506d26335d' }
You can also see your document in futon.
Although nano
is written using the "callback" style, it is easy enough to switch to a "Promises" style, using the Bluebird library:
var Promise = require('bluebird');
var mydb = require('nano')('http://localhost:5984/animaldb');
// create Promise-compatible versions of all functions
Promise.promisifyAll(mydb);
// now we have "get" (callback compatible) and "getAsync" (Promise compatible)
animals.getAsync('doc1').then(function(doc) {
console.log('the doc is', doc);
}).catch(console.error);
Configuring nano to use your database server is as simple as:
var nano = require('nano')('http://localhost:5984'),
db = nano.use('foo');
If you don't need to instrument database objects you can simply:
// nano parses the URL and knows this is a database
var db = require('nano')('http://localhost:5984/foo');
You can also pass options to the require to specify further configuration options you can pass an object literal instead:
// nano parses the URL and knows this is a database
var opts = {
url: "http://localhost:5984/foo",
requestDefaults: { "proxy" : "http://someproxy" },
log: function(id, args) {
console.log(id, args);
}
};
var db = require('nano')(opts);
Please check request for more information on the defaults. They support features like cookie jar, proxies, ssl, etc.
You can tell nano to not parse the URL (maybe the server is behind a proxy, is accessed through a rewrite rule or other):
// nano does not parse the URL and return the server api
// "http://localhost:5984/prefix" is the CouchDB server root
var couch = require('nano')(
{ url : "http://localhost:5984/prefix"
parseUrl : false
});
var db = couch.use('foo');
A very important configuration parameter if you have a high traffic website and are using nano
is setting up the pool.size
. By default, the Node.js HTTP global agent (client) has a certain size of active connections that can run simultaneously, while others are kept in a queue. Pooling can be disabled by setting the agent
property in requestDefaults
to false
, or adjust the global pool size using:
http.globalAgent.maxSockets = 20;
You can also increase the size in your calling context using requestDefaults
if this is problematic. Refer to the request documentation and examples for further clarification.
Here's an example explicitly using the keep alive agent (installed using npm install agentkeepalive
), especially useful to limit your open sockets when doing high-volume access to CouchDB on localhost:
var agentkeepalive = require('agentkeepalive');
var myagent = new agentkeepalive({
maxSockets: 50,
maxKeepAliveRequests: 0,
maxKeepAliveTime: 30000
});
var db = require('nano')(
{ url: "http://localhost:5984/foo",
requestDefaults : { "agent" : myagent }
});
Creates a CouchDB database with the given name
:
nano.db.create('alice', function(err, body) {
if (!err) {
console.log('database alice created!');
}
});
Get information about the database name
:
nano.db.get('alice', function(err, body) {
if (!err) {
console.log(body);
}
});
Destroys the database name
:
nano.db.destroy('alice', function(err, body){
});
Lists all the CouchDB databases:
nano.db.list(function(err, body) {
// body is an array
body.forEach(function(db) {
console.log(db);
});
});
Compacts name
, if designname
is specified also compacts its views.
Replicates source
to target
with options opts
. The target
database
has to exist, add create_target:true
to opts
to create it prior to
replication:
nano.db.replicate('alice', 'http://admin:password@otherhost.com:5984/alice',
{ create_target:true }, function(err, body) {
if (!err)
console.log(body);
});
Enables replication using the new CouchDB api from source
to target
with options opts
. target
has to exist, add create_target:true
to
opts
to create it prior to replication. Replication will survive server restarts.
nano.db.replication.enable('alice', 'http://admin:password@otherhost.com:5984/alice',
{ create_target:true }, function(err, body) {
if (!err)
console.log(body);
});
Queries the state of replication using the new CouchDB API. The id
comes from the response
given by the call to replication.enable
:
nano.db.replication.enable('alice', 'http://admin:password@otherhost.com:5984/alice',
{ create_target:true }, function(err, body) {
if (!err) {
nano.db.replication.query(body.id, function(error, reply) {
if (!err)
console.log(reply);
}
}
});
Disables replication using the new CouchDB API. The id
comes from the response given
by the call to replication.enable
:
nano.db.replication.enable('alice', 'http://admin:password@otherhost.com:5984/alice',
{ create_target:true }, function(err, body) {
if (!err) {
nano.db.replication.disable(body.id, function(error, reply) {
if (!err)
console.log(reply);
}
}
});
Asks for the changes feed of name
, params
contains additions
to the query string.
nano.db.changes('alice', function(err, body) {
if (!err) {
console.log(body);
}
});
Uses Follow to create a solid changes feed. Please consult follow
documentation for more information as this is a very complete API on it's own:
var feed = db.follow({since: "now"});
feed.on('change', function (change) {
console.log("change: ", change);
});
feed.follow();
process.nextTick(function () {
db.insert({"bar": "baz"}, "bar");
});
Gets database information:
nano.db.info(function(err, body) {
if (!err) {
console.log('got database info', body);
}
});
Returns a database object that allows you to perform operations against that database:
var alice = nano.use('alice');
alice.insert({ happy: true }, 'rabbit', function(err, body) {
// do something
});
Alias for nano.use
Alias for nano.use
Alias for nano.use
Makes a custom request to CouchDB. This can be used to create your own HTTP request to the CouchDB
server, to perform operations where there is no nano
function that encapsulates it. The available opts
are:
opts.db
– the database nameopts.method
– the http method, defaults toget
opts.path
– the full path of the request, overridesopts.doc
andopts.att
opts.doc
– the document nameopts.att
– the attachment nameopts.qs
– query string parameters, appended after any existingopts.path
,opts.doc
, oropts.att
opts.content_type
– the content type of the request, default tojson
opts.headers
– additional http headers, overrides existing onesopts.body
– the document or attachment bodyopts.encoding
– the encoding for attachmentsopts.multipart
– array of objects for multipart request
Alias for nano.request
An object containing the nano
configurations, possible keys are:
url
- the CouchDB URLdb
- the database name
Listen to db updates, the available params
are:
params.feed
– Type of feed. Can be one oflongpoll
: Closes the connection after the first event.continuous
: Send a line of JSON per event. Keeps the socket open until timeout.eventsource
: Like, continuous, but sends the events in EventSource format.params.timeout
– Number of seconds until CouchDB closes the connection. Default is 60.params.heartbeat
– Whether CouchDB will send a newline character (\n) on timeout. Default is true.
** changed in version 6 **
Use Follow to create a solid
_db_updates
feed.
Please consult follow documentation for more information as this is a very complete api on it's own
var feed = nano.followUpdates({since: "now"});
feed.on('change', function (change) {
console.log("change: ", change);
});
feed.follow();
process.nextTick(function () {
nano.db.create('alice');
});
Inserts doc
in the database with optional params
. If params is a string, it's assumed it is the intended document _id
. If params is an object, it's passed as query string parameters and docName
is checked for defining the document _id
:
var alice = nano.use('alice');
alice.insert({ happy: true }, 'rabbit', function(err, body) {
if (!err)
console.log(body);
});
The insert
function can also be used with the method signature db.insert(doc,[callback])
, where the doc
contains the _id
field e.g.
var alice = nano.use('alice')
alice.insert({ _id: 'myid', happy: true }, function(err, body) {
if (!err)
console.log(body)
})
and also used to update an existing document, by including the _rev
token in the document being saved:
var alice = nano.use('alice')
alice.insert({ _id: 'myid', _rev: '1-23202479633c2b380f79507a776743d5', happy: false }, function(err, body) {
if (!err)
console.log(body)
})
Removes a document from CouchDB whose _id
is docname
and who's revision is _rev
:
alice.destroy('rabbit', '3-66c01cdf99e84c83a9b3fe65b88db8c0', function(err, body) {
if (!err)
console.log(body);
});
Gets a document from CouchDB whose _id
is docname
:
alice.get('rabbit', function(err, body) {
console.log(body);
});
or with optional query string params
:
alice.get('rabbit', { revs_info: true }, function(err, body) {
console.log(body);
});
Same as get
but lightweight version that returns headers only:
alice.head('rabbit', function(err, _, headers) {
if (!err)
console.log(headers);
});
Copies the contents (and attachments) of a document to a new document, or overwrite an existing target document
alice.copy('rabbit', 'rabbit2', { overwrite: true }, function(err, _, headers) {
if (!err)
console.log(headers);
});
Bulk operations(update/delete/insert) on the database, refer to the CouchDB doc e.g:
var documents = [
{ a:1, b:2 },
{ _id: 'tiger', striped: true}
];
alice.bulk({docs:documents}, function(err, body) {
console.log(body);
});
List all the docs in the database .
alice.list(function(err, body) {
if (!err) {
body.rows.forEach(function(doc) {
console.log(doc);
});
}
});
or with optional query string additions params
:
alice.list({include_docs: true}, function(err, body) {
if (!err) {
body.rows.forEach(function(doc) {
// output eacj document's body
console.log(doc.doc);
});
}
});
Bulk fetch of the database documents, docnames
are specified as per
CouchDB doc.
additional query string params
can be specified, include_docs
is always set
to true
.
var keys = ['tiger', 'zebra', 'donkey'];
alice.fetch({keys: keys}, function(err, data) {
console.log(data);
});
** changed in version 6 **
Bulk fetch of the revisions of the database documents, docnames
are specified as per
CouchDB doc.
additional query string params
can be specified, this is the same method as fetch but
include_docs
is not automatically set to true
.
Create index on database fields, as specified in CouchDB doc.
var indexDef = {
index: { fields: ['foo'] },
name: 'fooindex'
};
alice.createIndex(indexDef, function(err, result) {
console.log(result);
});
Inserts a doc
together with attachments
and params
. If params is a string, it's assumed as the intended document _id
. If params is an object, its passed as query string parameters and docName
is checked for defining the _id
. Refer to the doc for more details.
The attachments
parameter must be an array of objects with name
, data
and content_type
properties.
var fs = require('fs');
fs.readFile('rabbit.png', function(err, data) {
if (!err) {
alice.multipart.insert({ foo: 'bar' }, [{name: 'rabbit.png', data: data, content_type: 'image/png'}], 'mydoc', function(err, body) {
if (!err)
console.log(body);
});
}
});
Get docname
together with its attachments via multipart/related
request with optional query string additions params
. Refer to the
doc for more details. The multipart response body is a Buffer
.
alice.multipart.get('rabbit', function(err, buffer) {
if (!err)
console.log(buffer.toString());
});
Inserts an attachment attname
to docname
, in most cases
params.rev
is required. Refer to the
doc for more details.
var fs = require('fs');
fs.readFile('rabbit.png', function(err, data) {
if (!err) {
alice.attachment.insert('rabbit', 'rabbit.png', data, 'image/png',
{ rev: '12-150985a725ec88be471921a54ce91452' }, function(err, body) {
if (!err)
console.log(body);
});
}
});
or using pipe
:
var fs = require('fs');
fs.createReadStream('rabbit.png').pipe(
alice.attachment.insert('new', 'rab.png', null, 'image/png')
);
Get docname
's attachment attname
with optional query string additions
params
.
var fs = require('fs');
alice.attachment.get('rabbit', 'rabbit.png', function(err, body) {
if (!err) {
fs.writeFile('rabbit.png', body);
}
});
or using pipe
:
var fs = require('fs');
alice.attachment.get('rabbit', 'rabbit.png').pipe(fs.createWriteStream('rabbit.png'));
changed in version 6
Destroy attachment attname
of docname
's revision rev
.
alice.attachment.destroy('rabbit', 'rabbit.png',
{rev: '1-4701d73a08ce5c2f2983bf7c9ffd3320'}, function(err, body) {
if (!err)
console.log(body);
});
Calls a view of the specified designname
with optional query string params
. If you're looking to filter the view results by key(s) pass an array of keys, e.g
{ keys: ['key1', 'key2', 'key_n'] }
, as params
.
alice.view('characters', 'happy_ones', {
'key': 'Tea Party',
'include_docs': true
}, function(err, body) {
if (!err) {
body.rows.forEach(function(doc) {
console.log(doc.value);
});
}
});
or
alice.view('characters', 'soldiers', {
'keys': ['Hearts', 'Clubs']
}, function(err, body) {
if (!err) {
body.rows.forEach(function(doc) {
console.log(doc.value);
});
}
});
When params
is not supplied, or no keys are specified, it will simply return all documents in the view:
alice.view('characters', 'happy_ones', function(err, body) {
if (!err) {
body.rows.forEach(function(doc) {
console.log(doc.value);
});
}
});
alice.view('characters', 'happy_ones', { include_docs: true }, function(err, body) {
if (!err) {
body.rows.forEach(function(doc) {
console.log(doc.value);
});
}
});
Calls a list function fed by the given view from the specified design document.
alice.viewWithList('characters', 'happy_ones', 'my_list', function(err, body) {
if (!err) {
console.log(body);
}
});
Calls a show function from the specified design for the document specified by doc_id with
optional query string additions params
.
alice.show('characters', 'format_doc', '3621898430', function(err, doc) {
if (!err) {
console.log(doc);
}
});
Take a look at the couchdb wiki for possible query paramaters and more information on show functions.
Calls the design's update function with the specified doc in input.
db.atomic("update", "inplace", "foobar",
{field: "foo", value: "bar"}, function (error, response) {
assert.equal(error, undefined, "failed to update");
assert.equal(response.foo, "bar", "update worked");
});
Note that the data is sent in the body of the request. An example update handler follows:
"updates": {
"in-place" : "function(doc, req) {
var field = req.form.field;
var value = req.form.value;
var message = 'set '+field+' to '+value;
doc[field] = value;
return [doc, message];
}"
Calls a view of the specified design with optional query string additions params
.
alice.search('characters', 'happy_ones', { q: 'cat' }, function(err, doc) {
if (!err) {
console.log(doc);
}
});
Check out the tests for a fully functioning example.
Nano supports making requests using CouchDB's cookie authentication functionality. There's an example in coffeescript, but essentially you just:
var nano = require('nano')('http://localhost:5984'),
username = 'user',
userpass = 'pass',
callback = console.log, // this would normally be some callback
cookies = {}; // store cookies, normally redis or something
nano.auth(username, userpass, function (err, body, headers) {
if (err) {
return callback(err);
}
if (headers && headers['set-cookie']) {
cookies[user] = headers['set-cookie'];
}
callback(null, "it worked");
});
Reusing a cookie:
var auth = "some stored cookie",
callback = console.log, // this would normally be some callback
alice = require('nano')(
{ url : 'http://localhost:5984/alice', cookie: 'AuthSession=' + auth });
alice.insert(doc, function (err, body, headers) {
if (err) {
return callback(err);
}
// change the cookie if CouchDB tells us to
if (headers && headers['set-cookie']) {
auth = headers['set-cookie'];
}
callback(null, "it worked");
});
Getting current session:
var nano = require('nano')({url: 'http://localhost:5984', cookie: 'AuthSession=' + auth});
nano.session(function(err, session) {
if (err) {
return console.log('oh noes!')
}
console.log('user is %s and has these roles: %j',
session.userCtx.name, session.userCtx.roles);
});
If your application needs to generate UUIDs, then CouchDB can provide some for you
nano.uuids(3, callback);
// { uuid: [
// '5d1b3ef2bc7eea51f660c091e3dffa23',
// '5d1b3ef2bc7eea51f660c091e3e006ff',
// '5d1b3ef2bc7eea51f660c091e3e007f0',
//]}
The first parameter is the number of uuids to generate. If omitted, it defaults to 1.
nano
is minimalistic but you can add your own features with
nano.request(opts, callback)
For example, to create a function to retrieve a specific revision of the
rabbit
document:
function getrabbitrev(rev, callback) {
nano.request({ db: 'alice',
doc: 'rabbit',
method: 'get',
params: { rev: rev }
}, callback);
}
getrabbitrev('4-2e6cdc4c7e26b745c2881a24e0eeece2', function(err, body) {
if (!err) {
console.log(body);
}
});
You can pipe in nano like in any other stream. For example if our rabbit
document has an attachment with name picture.png
you can pipe it to a writable stream
:
var fs = require('fs'),
nano = require('nano')('http://127.0.0.1:5984/');
var alice = nano.use('alice');
alice.attachment.get('rabbit', 'picture.png').pipe(fs.createWriteStream('/tmp/rabbit.png'));
then open /tmp/rabbit.png
and you will see the rabbit picture.
- article: nano - a minimalistic CouchDB client for nodejs
- article: getting started with Node.js and CouchDB
- article: document update handler support
- article: nano 3
- article: securing a site with CouchDB cookie authentication using Node.js and nano
- article: adding copy to nano
- article: how to update a document with nano
- article: thoughts on development using CouchDB with Node.js
- example in the wild: nanoblog
Check issues
To run (and configure) the test suite simply:
cd nano
npm install
npm test
After adding a new test you can run it individually (with verbose output) using:
nano_env=testing node tests/doc/list.js list_doc_params
where list_doc_params
is the test name.
- code:
git clone git://github.com/apache/couchdb-nano.git
- home: http://github.com/apache/couchdb-nano
- bugs: http://github.com/apache/couchdb-nano/issues
- build:
- deps:
- chat: Freenode IRC @ #couchdb-dev
To create a new release of nano. Run the following commands on the master branch
npm version {patch|minor|major}
github push origin master --tags
npm publish