Mongodb v3.4

You need to do the following to create a secure database:

Make sure the user starting the process has permissions and that the directories exist (/data/db in this case).

1) Start MongoDB without access control.

mongod --port 27017 --dbpath /data/db

2) Connect to the instance.

mongo --port 27017

3) Create the user administrator (in the admin authentication database).

use admin
db.createUser(
  {
    user: "myUserAdmin",
    pwd: "abc123",
    roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
  }
)

4) Re-start the MongoDB instance with access control.

mongod --auth --port 27017 --dbpath /data/db

5) Connect and authenticate as the user administrator.

mongo --port 27017 -u "myUserAdmin" -p "abc123" --authenticationDatabase "admin"

6) Create additional users as needed for your deployment (e.g. in the test authentication database).

use test
db.createUser(
  {
    user: "myTester",
    pwd: "xyz123",
    roles: [ { role: "readWrite", db: "test" },
             { role: "read", db: "reporting" } ]
  }
)

7) Connect and authenticate as myTester.

mongo --port 27017 -u "myTester" -p "xyz123" --authenticationDatabase "test"

I basically just explained the short version of the official docs here: https://docs.mongodb.com/master/tutorial/enable-authentication/

OMG, what a gas plant, that top answer!

All you need to do is to:

1. Edit your config, e.g. C:\Program Files\MongoDB\Server\4.4\bin\mongodb.cfg
2. Turn the security: authorization: to enabled, as illustrated; note that this sub-entry may be missing completely. Just add it then.
3. Restart your MongoDB Server service from the Windows Services control panel.

Obviously, if, following this, set up a read/readWrite role-based policy, that will make much more sense.

Ref: https://docs.mongodb.com/manual/tutorial/configure-scram-client-authentication/

I've just tested this using phpunit, works as expected.

you can create an admin user or another role. run it on mongo shell.

db.createUser({user: "username", pwd: "password", roles: ["dbAdmin"]})

if you get SCRAM-SHA-256error you can set the SHA-1 mechanism.

db.createUser({user: "username", pwd: "password", roles: ["dbAdmin"], mechanisms: ["SCRAM-SHA-1"]})