Setup Cluster

Create Instances

Create directories:

mkdir -p /tmp/mongodb/rs-{0,1,2}

In shell, run:

mongod --dbpath /tmp/mongodb/rs-0 --replSet rs --port 27021 --bind_ip localhost --smallfiles --oplogSize 128
mongod --dbpath /tmp/mongodb/rs-1 --replSet rs --port 27022 --bind_ip localhost --smallfiles --oplogSize 128
mongod --dbpath /tmp/mongodb/rs-2 --replSet rs --port 27023 --bind_ip localhost --smallfiles --oplogSize 128

Initiate ReplicaSet

Run client to initiate ReplicaSet:

mongo --port 27021

Create ReplicaSet configuration:

rs.initiate({
    _id : 'rs',
    members: [
      { _id : 0, host : "localhost:27021" },
      { _id : 1, host : "localhost:27022" },
      { _id : 2, host : "localhost:27023" }
    ]
})

Review with:

rs.conf()

Configuring Authorization

Establishing Auth

Connecting to ReplicaSet

mongo "mongodb://localhost:27021,localhost:27022,localhost:27023/?replicaSet=rs"

Establishing auth:

use admin;

Then, create a user:

db.createUser({ user: "ft-user", pwd: "3aPFfSIgebQcW1nhliXi", roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]})

Exit:

exit

Create Keyfile

Create a keyfile for internal authentication:

openssl rand -base64 360 > /tmp/mongodb/keyfile
chmod 600 /tmp/mongodb/keyfile

Keyfile must not be world-readable. Otherwise, mongod will complain:

2018-09-02T12:29:58.997+0200 I ACCESS   [main] permissions on /tmp/mongodb/keyfile are too open

Running Cluster with Authentication

Rerun all replica members. Repeat this for all three members:

mongod --replSet rs --port 27021 --bind_ip localhost --dbpath /tmp/mongodb/rs-0 --smallfiles --oplogSize 128 --auth --keyFile /tmp/mongodb/keyfile
mongod --replSet rs --port 27022 --bind_ip localhost --dbpath /tmp/mongodb/rs-1 --smallfiles --oplogSize 128 --auth --keyFile /tmp/mongodb/keyfile
mongod --replSet rs --port 27023 --bind_ip localhost --dbpath /tmp/mongodb/rs-2 --smallfiles --oplogSize 128 --auth --keyFile /tmp/mongodb/keyfile

Connect to Cluster with Proper Credentials

Now, re-authenticate with proper credentials:

mongo "mongodb://localhost:27021,localhost:27022,localhost:27023/?replicaSet=rs" --username 'ft-user' --password 3aPFfSIgebQcW1nhliXi --authenticationDatabase admin

The following command should work fine now:

show dbs

>> Home

Running MongoDB ReplicaSet on localhost

2019/01/11