mongoDB

MongoDB

Containerised mongoDB single node instance

Configuration

Create security keyfile for the replicas to authenticate eachother with

openssl rand -base64 756 > mykey.key

chmod 400 mykey.key

sudo chown 999:999 mykey.key

Connect with initialsed root user details

mongosh -u root -p rootpassword

Initiate the replica set

rs.initiate()

Change config so replica set members work correctly

cfg = rs.conf()

cfg.members[0].host = "localhost:27017"

rs.reconfig(cfg)

Add a new user for creating users and roles

use admin
db.createUser(
  {
    user: "userAdmin",
    pwd: passwordPrompt(),
    roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
  }
)

Disconnect and then login to the admin user

use admin
db.auth("userAdmin", passwordPrompt())

Create a new user to read and write to testdb

use testdb
db.createUser(
  {
    user: "workerUser",
    pwd: passwordPrompt(),
    roles: [ { role: "readWrite", db: "testdb" }],
  }
)

Insert data into collection dayta in testdb

db.dayta.insertOne({name:"Cathal"})

Change root user password

mongosh admin -u root -p rootpassword
db.changeUserPassword("root", passwordPrompt())

Create a user for the metrics exporter

use admin
db.createUser(
  {
    user: "mongodb_exporter",
    pwd: passwordPrompt(),
    roles: [
        { role: "clusterMonitor", db: "admin" },
        { role: "read", db: "local" }
    ]
  }
)

Place the mongoDB exporter user password into an env

echo "MONGODB_CONNECT_URL=mongodb://mongodb_exporter:[PASSWORDHERE]@mongodb:27017" > .env

Restart both containers to let the mongoDB exporter connect

Creating Collections With Schemas

First marshal the struct into JSON. Make sure all json keys are all lowercase before proceeding to create the schema.

Use JSON Schema to translate the JSON to a valid mongo DB schema. However,

• All $id, example and default tags must be removed.
• All integer tags must also be replaced with number

db.createCollection("collectionName", {validator: {$jsonSchema:{....}}})