MongoDB In-Memory Server

Installation

Requirements

Choose the Correct Package

Configuring which mongod binary to use

export MONGOMS_DOWNLOAD_URL=https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1804-4.2.8.tgz
export MONGOMS_VERSION=4.2.8

Usage

Simple server start

import { MongoMemoryServer } from 'mongodb-memory-server';
// This will create an new instance of "MongoMemoryServer" and automatically start it
const mongod = await MongoMemoryServer.create();
const uri = mongod.getUri();
// The Server can be stopped again with
await mongod.stop();

Available options for MongoMemoryServer

const mongod = new MongoMemoryServer({
 instance?: {
 port?: number, // by default choose any free port
 ip?: string, // by default '127.0.0.1', for binding to all IP addresses set it to `::,0.0.0.0`,
 dbName?: string, // by default '' (empty string)
 dbPath?: string, // by default create in temp directory
 storageEngine?: string, // by default `ephemeralForTest`(unless mongodb 7.0.0, where its `wiredTiger`), available engines: [ 'ephemeralForTest', 'wiredTiger' ]
 replSet?: string, // by default no replica set, replica set name
 args?: string[], // by default no additional arguments, any additional command line arguments for `mongod` `mongod` (ex. ['--notablescan'])
 auth?: boolean, // add "--auth" argument, dont use this directly use top-level "auth"
 },
 binary?: {
 version?: string, // by default '7.0.14'
 downloadDir?: string, // see the documentation on what is chosen by default https://typegoose.github.io/mongodb-memory-server/docs/api/config-options#download_dir
 platform?: string, // by default os.platform()
 arch?: string, // by default os.arch()
 checkMD5?: boolean, // by default false OR process.env.MONGOMS_MD5_CHECK
 systemBinary?: string, // by default undefined or process.env.MONGOMS_SYSTEM_BINARY
 },
 // using "auth" will manage "instance.auth"
 auth?: {
 // enable needs to be set to "true", otherwise automatic user creation is by default disabled
 enable?: boolean, // enable automatic user creation
 customRootName?: string, // by default "mongodb-memory-server-root"
 customRootPwd?: string, // by default "rootuser"
 force?: boolean, // force creation of users
 keyfileContent?: string, // by default "0123456789" (only useful for replsets)
 extraUsers?: [{
 // see mongodb documentation https://docs.mongodb.com/manual/reference/method/db.createUser/#definition)
 createUser: string, // user name
 pwd: string, // user password
 roles: UserRoles[], // user roles
 database?: string, // which database the user is created on
 customData?: Record<string, any>, // any arbitrary information, see mongodb documentation
 mechanisms?: ('SCRAM-SHA-1' | 'SCRAM-SHA-256')[],
 authenticationRestrictions?: {
 clientSource?: string;
 serverAddress?: string;
 }[],
 digestPassword?: boolean,
 }],
 },
});

Replica Set start

import { MongoMemoryReplSet } from 'mongodb-memory-server';
// This will create an new instance of "MongoMemoryReplSet" and automatically start all Servers
const replset = await MongoMemoryReplSet.create({ replSet: { count: 4 } }); // This will create an ReplSet with 4 members
const uri = replset.getUri();
// The ReplSet can be stopped again with
await replset.stop();

Available options for MongoMemoryReplSet

const replSet = new MongoMemoryReplSet({
 binary: binaryOpts, // same as for MongoMemoryServer
 instanceOpts: [
 {
 args, // any additional instance specific args
 port, // port number for the instance
 dbPath, // path to database files for this instance
 storageEngine, // same storage engine options
 },
 // each entry will result in a MongoMemoryServer (replSet.count will not limit the amount spawned by "instanceOpts")
 ],
 // unless otherwise noted below these values will be in common with all instances spawned:
 replSet: {
 name, // replica set name (default: 'testset')
 auth?: boolean | AutomaticAuth, // enable auth, for options see #available-options-for-mongomemoryserver
 args, // any args specified here will be combined with any per instance args from `instanceOpts`
 count, // number of additional `mongod` processes to start (will not start any extra if instanceOpts.length > replSet.count); (default: 1)
 dbName, // default database for db URI strings
 ip, // by default '127.0.0.1', for binding to all IP addresses set it to `::,0.0.0.0`
 spawn, // spawn options when creating the child processes
 storageEngine, // default storage engine for instance. (Can be overridden per instance)
 configSettings: {
 // Optional settings for 'replSetInitiate' command. See https://docs.mongodb.com/manual/reference/command/replSetInitiate/
 chainingAllowed: boolean, // When true it allows secondary members to replicate from other secondary members. When false, secondaries can replicate only from the primary.
 heartbeatTimeoutSecs: number, // Number of seconds that the replica set members wait for a successful heartbeat from each other. If a member does not respond in time, other members mark the delinquent member as inaccessible.
 heartbeatIntervalMillis: number, // The frequency in milliseconds of the heartbeats.
 electionTimeoutMillis: number, // The time limit in milliseconds for detecting when a replica set’s primary is unreachable.
 catchUpTimeoutMillis: number, // Time limit for a newly elected primary to sync (catch up) with the other replica set members that may have more recent writes.
 },
 },
});

Config Options

Simple test with MongoClient in Jest

Provide connection string to mongoose

// assuming mongoose@6.x
import mongoose from 'mongoose';
import { MongoMemoryServer } from 'mongodb-memory-server';
const mongoServer = await MongoMemoryServer.create();
(async () => {
 await mongoose.connect(mongoServer.getUri(), { dbName: "verifyMASTER" });
 // your code here
 
 await mongoose.disconnect();
})();

Test Runner Examples

Docker Alpine

Enable Debug Mode

MONGOMS_DEBUG=1 # also available case-insensitive values: "on" "yes" "true"

{
 "config": {
 "mongodbMemoryServer": {
 "debug": "1" // also available case-insensitive values: "on" "yes" "true"
 }
 }
}

Contributing

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