enable_oplog_meteor.sh

#!/bin/bash

# Script to enable oplog tailing in a production meteor deployment using mongodb 4.0 or later

echo "# Enabling replication, required for oplog tailing" >> /etc/mongod.conf
echo "replication:" >> /etc/mongod.conf
echo "  oplogSizeMB: 100" >> /etc/mongod.conf
echo "  replSetName: rs0" >> /etc/mongod.conf

systemctl restart mongod
sleep 2

echo 'rs.initiate({ "_id" : "rs0", "version" : 1, "members" : [{ "_id" : 0, "host" : "127.0.0.1:27017" }]})' | mongo

sleep 1

mongo admin -eval 'db.createUser({user: "oplogger", pwd: "PasswordForOplogger", roles: ["read"]})'

echo 
echo "All set! Now use"
echo "  MONGO_OPLOG_URL=mongodb://oplogger:PasswordForOplogger@localhost:27017/local?replicaSet=rs0\&authSource=admin"
echo "in your meteor app"

Download and run in one line:

curl https://gist.githubusercontent.com/chfritz/6fc8dc807cf12816f6cf5c6be2f5f837/raw/c81370f5c77f3dcc50c04e9685f23550e755c084/enable_oplog_meteor.sh | sudo sh