Resolve #3459294 "Mongodb better readiness"

Related to #3459294

db/mongodb-7/conf/mongo-init-rs.sh

-#!/bin/bash
-
-echo "###### Waiting for mongo primary member instance startup.."
-until mongosh --host localhost:27017 --eval 'quit(db.runCommand({ ping: 1 }).ok ? 0 : 2)' &>/dev/null; do
-  printf '.'
-  sleep 1
-done
-echo "###### Working mongo primary member instance found, initiating user setup & initializing rs setup.."
-
-# setup user + pass and initialize replica sets
-mongosh --host localhost:27017 <<EOF
-var rootUser = 'db';
-var rootPassword = 'db';
-var admin = db.getSiblingDB('admin');
-admin.auth(rootUser, rootPassword);
-
-var config = {
-    "_id": "dbrs",
-    "version": 1,
-    "members": [
-        {
-            "_id": 1,
-            "host": "localhost:27017",
-            "priority": 2
-        },
-        {
-            "_id": 2,
-            "host": "localhost:27018",
-            "priority": 1
-        },
-        {
-            "_id": 3,
-            "host": "localhost:27019",
-            "priority": 1,
-            "arbiterOnly": true
-        }
-    ]
-};
-rs.initiate(config, { force: true });
-rs.status();
-EOF
-
-# use rs.reconfig() to change the config instead of rs.initiate() for startup.