how to check if mongodb is up and ready to accept connections from bash script?

Question

I have a bash shell script which does a bunch of stuff before trying to mongorestore.

I want to make sure that not only MongoDB is up, but it is also re

Answer 1

I needed Mongo running in Docker to initialize before creating a user. I combined the answers of Tom and Björn. This is the script I am using:

#!/bin/bash

# Wait until Mongo is ready to accept connections, exit if this does not happen within 30 seconds
COUNTER=0
until mongo --host ${MONGO_HOST} --eval "printjson(db.serverStatus())"
do
  sleep 1
  COUNTER=$((COUNTER+1))
  if [[ ${COUNTER} -eq 30 ]]; then
    echo "MongoDB did not initialize within 30 seconds, exiting"
    exit 2
  fi
  echo "Waiting for MongoDB to initialize... ${COUNTER}/30"
done

# Connect to the MongoDB and execute the create users script
mongo ${FWRD_API_DB} /root/create-user.js --host ${MONGO_HOST} -u ${MONGO_ROOT_USER} -p ${MONGO_ROOT_PASSWORD} --authenticationDatabase admin