octohedron/ansible-vagrant-mongodb-cluster

Deploy a local MongoDB 4.0.10 cluster with a single command

Ansible Vagrant MongoDB Cluster

Deploy a local MongoDB 4.0.10 cluster with a single command.

Overview

The motivation is having a local MongoDB cluster for testing purposes, along with examples on how to set up everything with ansible. It can be easily modified to run on any cloud provider, such as GCP/AWS, etc.

Cluster topology and configuration

• 1 Mongos / router
• 1 Config server
• 1 Shard with 3 nodes
  • 2 in replication
  • 1 arbiter

Automation

Vagrant stage

1. Uses an environment variable to choose which nework interface to bind to
2. Boots up 5 VMs with 512MB of ram and 1vCPU each, in the 192.168.18... range

Ansible stage

1. A common playbook is run in all VMs, which
   1. Installs MongoDB
   2. Copies the hosts file and the KeyFile
   3. Creates the data directory and sets permissions
2. Configures each node according to it's role, i.e. each node in the replica set, the config server, etc
3. Adds users and enables security
4. Adds the shards to the cluster

Usage

Requirements

• Install Vagrant
• Install Ansible

Setup

If you already have Vagrant and Ansible installed, then you just need to configure the network interface for Virtualbox to bind to.

To get a list of network interfaces

$ vboxmanage list bridgedifs

Then choose the one you want, for example enp2s0 and

$ export NETINT=enp2s0

That will be used by the Vagrantfile to bind the virtual machines.

Note: If your local network is not in the 192.168.18... range, you might need to edit the Vagrantfile and the ansible inventory to match your network's.

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Set a username and password for the cluster

$ export mongo_usr=username
$ export mongo_pw=hunter2

Run it

If you have everything installed and you're running on OSx/Ubuntu, just run

$ ./run.sh

That should boot up the VMs and provision the whole cluster in just a few minutes, depending on the hardware.

Try it

$ mongo --host 192.168.18.19:27017 -u 'username' -p 'hunter2' --authenticationDatabase 'admin'

MongoDB shell version v4.0.10
connecting to: mongodb://192.168.18.19:27017/?authSource=admin&gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("02ce446b-b36c-48e2-8566-49e52abeb8d9") }
MongoDB server version: 4.0.10

mongos> db.adminCommand({ listShards: 1})
{
  shards: [
    {
      _id: "sh0rs0",
      host: "sh0rs0/arbiter:27017,sh0n0:27017,sh0n1:27017",
      state: 1
    }
  ],
  ok: 1,
  operationTime: Timestamp(1561660870, 1),
  $clusterTime: {
    clusterTime: Timestamp(1561660870, 1),
    signature: {
      hash: BinData(0, "M0hV9SM4WXx8NvUOMIurqT0N6gY="),
      keyId: NumberLong("6707282265308659713")
    }
  }
};

Other commands

Destroy the cluster

$ ./destroy.sh

Reset the cluster, destroy and re-create the cluster from scratch

$ ./reset.sh

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CONTRIBUTIONS: YES

LICENSE: MIT