mongo-connection-string

Utilities to help with MongoDB connection strings and related tasks.

Parsing Connection Strings

Parse a connection string into ConnectionString object:

const { ConnectionString } = require('mongo-connection-string');
const connectionString = new ConnectionString('mongodb://user:p@ssw0rd@host1,host2:2700/db?w=majority');

The connection string object has the following fields:

{
  protocol: 'mongodb://',
  username: 'user',
  password: 'p@ssw0rd',
  hosts: [{ host: 'host1', port: null }, { host: 'host2', port: 2700 }],
  database: 'db',
  options: {
    w: 'majority'
  }
}

You can now write it as a MongoDB compatible URI, or a more human readable string:

connectionString.toURI();

//  Produces:
//  mongodb://user:p%40ssw0rd/db?readPreference=secondary

connectionString.toString();

//  Produces:
//  mongodb://user:********/db?readPreference=secondary
//  (a little bit safer to go into logs/error messages etc)!

Building Connection Strings

The ConnectionString constructor can also take the fields required to build a connection string:

const { ConnectionString } = require('mongo-connection-string');

const connectionString = ConnectionString({
  username: 'user',
  password: 'pwd',
  hosts: [{ host: 'host1' }],
  database: 'db',
  options: {
    readPreference: 'secondary'
  }
});

//  Write out the connection string.
console.log(connectionString.toURI());

Produces:

mongodb://user:pwd@host1/db?readPreference=secondary

Url Encoding

When parsing a connection string, encoded charecters are unencoded:

const { parse } = require('mongo-connection-string');
const connectionString = new ConnectionString('mongodb://%40dmin:P%40ssword%3C%3E%2F@host1,host2:2700/db?w=majority');

//  Write out the connection string.
console.log(connectionString.username);
console.log(connectionString.password);

Produces:

@dmin
P@ssword<>/

Similarly, connection string object usernames and passwords are encoded:

const { ConnectionString } = require('mongo-connection-string');

const connectionString = ConnectionString({
  username: '@dmin',
  password: 'P@ssword<>/',
  hosts: [{ host: 'localhost' }]
});

//  Write out the connection string.
console.log(connectionString.toURI());

Produces:

mongodb://%40dmin:P%40ssword%3C%3E%2F@localhost

This means you can actually use the library to clean up a non-url encoded connection string. This can be useful to allow connection strings to be input in a more readable way (mongo-monitor does this):

new ConnectionString('@dmin:P@ssword<>/@localhost').toURI();

Produces:

mongodb://%40dmin:P%40ssword%3C%3E%2F@localhost

Notes

• If no protocol is specifed, the library will assume mongodb:// should be used.
• If there is a % symbol in the username or password, the code will try to URI decode it. If this fails, it will assume the username or password is plain text with a % symbol as part of the password. This means that if your password is actually something like p%40ssword then this will be URI decoded to p@ssword.