Create user only if not exists in MongoDB (simple example)-CodePudding

I'm newby to MongoDB and .js.

I have a simple add_app_user.js script with the following content:

# MongoDB shell version v4.2.17
# Set the database to 'testdb'.
db = db.getSiblingDB('testdb');

# Create new user.
db.createUser(
   {
     user: "testuser",
     pwd: "testpass",
     roles: [ "readWrite" ]
   }
);

This works fine for the first time (when such a user doesn't exist).

I need to make it idempotent.

I couldn't find an simple to understand script that will check for the "testuser" availability in the "testdb" and run my script block only if the check fails.

CodePudding user response：

Try this:

if (db.getUser("testuser") == null) {  
   db.createUser(
     {
     user: "testuser",
     pwd: "testpass",
     roles: [ "readWrite" ]
     }
   );
}

NB, usually users are created in admin database. Actually I don't know any reason why they should be created anywhere else.