mongodb-runrs

Run a MongoDB replica set for learning and development, using just one command.

Introduction

Setting up a MongoDB replica set is an involved process, requiring quite a number of configurations to be made. With mongodb-runrs, you can now invoke a single command to set up an N-member replica set in less than 60 seconds. The replica set can be designed so that it doesn't interfere with any existing mongod processes you might have.

Prerequisites

• Ubuntu 18.04 LTS or 20.04 LTS is required.
• A copy of MongoDB is not required as it will be downloaded automatically.
• There are zero dependencies as only Bash shell scripts are used.

Installation

You can use an ordinary user account; superuser privilege is not required. Go to your home directory and clone a local copy of this repository:

$ cd ~
$ git clone https://github.com/wingkeet/mongodb-runrs.git

Getting Started

Choose your operating system and MongoDB version by editing mongodb.conf.

There are 3 Bash shell scripts: runrs.sh, mongoshell.sh and shutdown.sh. To run a replica set consisting of a primary node and two secondary nodes:

$ cd ~/mongodb-runrs
$ ./runrs.sh

To get into the mongo shell, use one of the following commands. If no port number is provided, it defaults to 28001 (primary).

$ ./mongoshell.sh
$ ./mongoshell.sh 28001
$ ./mongoshell.sh 28002
$ ./mongoshell.sh 28003

To shutdown the entire replica set:

$ ./shutdown.sh

To remove the entire project from your disk:

$ cd ~
$ rm -rf mongodb-runrs

How It Works

The runrs.sh shell script does the following things:

1. Reads configuration information from mongodb.conf.
2. Downloads the TGZ tarball of the MongoDB Community Server and extracts the contents into the mongodb subdirectory.
3. Creates the data and log subdirectories.
4. Runs 3 copies of the mongod daemon using port numbers 28001 (primary), 28002 and 28003 (secondaries). The name of the replica set is rstest. All of these parameters are configurable in mongodb.conf.
5. Calls rs.initiate(rsconf) to initialize the replica set.
6. Waits for the replica set to be ready. This step alone takes 13 seconds on my machine.

Additional Notes

By default, runrs.sh retains any databases found in the data directory. If you want a fresh install, use the --fresh option:

$ ./shutdown.sh
$ ./runrs.sh --fresh

Before doing a fresh install, you can configure your replica set by editing mongodb.conf. I will try my best to update it to reflect the latest version of MongoDB. Refer to mongodb.conf for details.

Authors

• Steve Leong - Initial work

License

This project is licensed under the MIT License - see the LICENSE file for details.