harveyconnor/a-mongodb-replica-set-docker-compose-readme.md

## a-mongodb-replica-set-docker-compose-readme.md

      
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              a-mongodb-replica-set-docker-compose-readme.md
            
          
    This will guide you through setting up a replica set in a docker environment using.

Docker Compose
MongoDB Replica Sets
Mongoose
Mongoose Transactions

Thanks to https://gist.github.com/asoorm for helping with their docker-compose file!

  
## docker-compose.yml
  mongo-setup:
    container_name: mongo-setup
    image: mongo
    restart: on-failure
    networks:
      default:
    volumes:
      - ./scripts:/scripts
    entrypoint: [ "/scripts/setup.sh" ] # Make sure this file exists (see below for the setup.sh)
    depends_on:
      - mongo1
      - mongo2
      - mongo3

  mongo1:
    hostname: mongo1
    container_name: localmongo1
    image: mongo
    expose:
      - 27017
    ports:
      - 27017:27017
    restart: always
    entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0", "--journal", "--dbpath", "/data/db", "--enableMajorityReadConcern", "false" ]
    volumes:
      - <VOLUME-DIR>/mongo/data1/db:/data/db # This is where your volume will persist. e.g. VOLUME-DIR = ./volumes/mongodb
      - <VOLUME-DIR>/mongo/data1/configdb:/data/configdb
  mongo2:
    hostname: mongo2
    container_name: localmongo2
    image: mongo
    expose:
      - 27017
    ports:
      - 27018:27017
    restart: always
    entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0", "--journal", "--dbpath", "/data/db", "--enableMajorityReadConcern", "false" ]
    volumes:
      - <VOLUME-DIR>/mongo/data2/db:/data/db # Note the data2, it must be different to the original set.
      - <VOLUME-DIR>/mongo/data2/configdb:/data/configdb
  mongo3:
    hostname: mongo3
    container_name: localmongo3
    image: mongo
    expose:
      - 27017
    ports:
      - 27019:27017
    restart: always
    entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0", "--journal", "--dbpath", "/data/db", "--enableMajorityReadConcern", "false" ]
    volumes:
      - <VOLUME-DIR>/mongo/data3/db:/data/db
      - <VOLUME-DIR>/mongo/data3/configdb:/data/configdb

## docker.sh
# NOTE: This is the simplest way of achieving a replicaset in mongodb with Docker.
# However if you would like a more automated approach, please see the setup.sh file and the docker-compose file which includes this startup script.

# run this after setting up the docker-compose This will instantiate the replica set.
# The id and hostname's can be tailored to your liking, however they MUST match the docker-compose file above.
docker-compose up -d
docker exec -it localmongo1 mongo

rs.initiate(
  {
    _id : 'rs0',
    members: [
      { _id : 0, host : "mongo1:27017" },
      { _id : 1, host : "mongo2:27017" },
      { _id : 2, host : "mongo3:27017", arbiterOnly: true }
    ]
  }
)

exit

## mongoose.js
// If on a linux server, use the hostname provided by the docker compose file
// e.g. HOSTNAME = mongo1, mongo2, mongo3

// If on MacOS add the following to your /etc/hosts file.
// 127.0.0.1  mongo1
// 127.0.0.1  mongo2
// 127.0.0.1  mongo3
// And use localhost as the HOSTNAME
mongoose.connect('mongodb://<HOSTNAME>:27017,<HOSTNAME>:27018,<HOSTNAME>:27019/<DBNAME>', {
  useNewUrlParser : true,
  useFindAndModify: false, // optional
  useCreateIndex  : true,
  replicaSet      : 'rs0', // We use this from the entrypoint in the docker-compose file
})

## setup.sh
#!/bin/bash

#MONGODB1=`ping -c 1 mongo1 | head -1  | cut -d "(" -f 2 | cut -d ")" -f 1`
#MONGODB2=`ping -c 1 mongo2 | head -1  | cut -d "(" -f 2 | cut -d ")" -f 1`
#MONGODB3=`ping -c 1 mongo3 | head -1  | cut -d "(" -f 2 | cut -d ")" -f 1`

MONGODB1=mongo1
MONGODB2=mongo2
MONGODB3=mongo3

echo "**********************************************" ${MONGODB1}
echo "Waiting for startup.."
until curl http://${MONGODB1}:27017/serverStatus\?text\=1 2>&1 | grep uptime | head -1; do
  printf '.'
  sleep 1
done

# echo curl http://${MONGODB1}:28017/serverStatus\?text\=1 2>&1 | grep uptime | head -1
# echo "Started.."


echo SETUP.sh time now: `date +"%T" `
mongo --host ${MONGODB1}:27017 <<EOF
var cfg = {
    "_id": "rs0",
    "protocolVersion": 1,
    "version": 1,
    "members": [
        {
            "_id": 0,
            "host": "${MONGODB1}:27017",
            "priority": 2
        },
        {
            "_id": 1,
            "host": "${MONGODB2}:27017",
            "priority": 0
        },
        {
            "_id": 2,
            "host": "${MONGODB3}:27017",
            "priority": 0
        }
    ],settings: {chainingAllowed: true}
};
rs.initiate(cfg, { force: true });
rs.reconfig(cfg, { force: true });
rs.slaveOk();
db.getMongo().setReadPref('nearest');
db.getMongo().setSlaveOk();
EOF

## transaction.js
async function transaction() {
  // Start the transaction.
  const session = await ModelA.startSession();
  session.startTransaction();

  try {
    const options = { session };

    // Try and perform operation on Model.
    const a = await ModelA.create([{ ...args }], options);

    // If the first operation succeeds this next one will get called.
    await ModelB.create([{ ...args }], options);

    // If all succeeded with no errors, commit and end the session.
    await session.commitTransaction();
    session.endSession();
    return a;
  } catch (e) {
    // If any error occured, the whole transaction fails and throws error.
    // Undos changes that may have happened.
    await session.abortTransaction();
    session.endSession();
    throw e;
  }
}
	mongo-setup:
	container_name: mongo-setup
	image: mongo
	restart: on-failure
	networks:
	default:
	volumes:
	- ./scripts:/scripts
	entrypoint: [ "/scripts/setup.sh" ] # Make sure this file exists (see below for the setup.sh)
	depends_on:
	- mongo1
	- mongo2
	- mongo3

	mongo1:
	hostname: mongo1
	container_name: localmongo1
	image: mongo
	expose:
	- 27017
	ports:
	- 27017:27017
	restart: always
	entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0", "--journal", "--dbpath", "/data/db", "--enableMajorityReadConcern", "false" ]
	volumes:
	- <VOLUME-DIR>/mongo/data1/db:/data/db # This is where your volume will persist. e.g. VOLUME-DIR = ./volumes/mongodb
	- <VOLUME-DIR>/mongo/data1/configdb:/data/configdb
	mongo2:
	hostname: mongo2
	container_name: localmongo2
	image: mongo
	expose:
	- 27017
	ports:
	- 27018:27017
	restart: always
	entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0", "--journal", "--dbpath", "/data/db", "--enableMajorityReadConcern", "false" ]
	volumes:
	- <VOLUME-DIR>/mongo/data2/db:/data/db # Note the data2, it must be different to the original set.
	- <VOLUME-DIR>/mongo/data2/configdb:/data/configdb
	mongo3:
	hostname: mongo3
	container_name: localmongo3
	image: mongo
	expose:
	- 27017
	ports:
	- 27019:27017
	restart: always
	entrypoint: [ "/usr/bin/mongod", "--bind_ip_all", "--replSet", "rs0", "--journal", "--dbpath", "/data/db", "--enableMajorityReadConcern", "false" ]
	volumes:
	- <VOLUME-DIR>/mongo/data3/db:/data/db
	- <VOLUME-DIR>/mongo/data3/configdb:/data/configdb
	# NOTE: This is the simplest way of achieving a replicaset in mongodb with Docker.
	# However if you would like a more automated approach, please see the setup.sh file and the docker-compose file which includes this startup script.

	# run this after setting up the docker-compose This will instantiate the replica set.
	# The id and hostname's can be tailored to your liking, however they MUST match the docker-compose file above.
	docker-compose up -d
	docker exec -it localmongo1 mongo

	rs.initiate(
	{
	_id : 'rs0',
	members: [
	{ _id : 0, host : "mongo1:27017" },
	{ _id : 1, host : "mongo2:27017" },
	{ _id : 2, host : "mongo3:27017", arbiterOnly: true }
	]
	}
	)

	exit
	// If on a linux server, use the hostname provided by the docker compose file
	// e.g. HOSTNAME = mongo1, mongo2, mongo3

	// If on MacOS add the following to your /etc/hosts file.
	// 127.0.0.1 mongo1
	// 127.0.0.1 mongo2
	// 127.0.0.1 mongo3
	// And use localhost as the HOSTNAME
	mongoose.connect('mongodb://<HOSTNAME>:27017,<HOSTNAME>:27018,<HOSTNAME>:27019/<DBNAME>', {
	useNewUrlParser : true,
	useFindAndModify: false, // optional
	useCreateIndex : true,
	replicaSet : 'rs0', // We use this from the entrypoint in the docker-compose file
	})
	#!/bin/bash

	#MONGODB1=`ping -c 1 mongo1 \| head -1 \| cut -d "(" -f 2 \| cut -d ")" -f 1`
	#MONGODB2=`ping -c 1 mongo2 \| head -1 \| cut -d "(" -f 2 \| cut -d ")" -f 1`
	#MONGODB3=`ping -c 1 mongo3 \| head -1 \| cut -d "(" -f 2 \| cut -d ")" -f 1`

	MONGODB1=mongo1
	MONGODB2=mongo2
	MONGODB3=mongo3

	echo "**********************************************" ${MONGODB1}
	echo "Waiting for startup.."
	until curl http://${MONGODB1}:27017/serverStatus\?text\=1 2>&1 \| grep uptime \| head -1; do
	printf '.'
	sleep 1
	done

	# echo curl http://${MONGODB1}:28017/serverStatus\?text\=1 2>&1 \| grep uptime \| head -1
	# echo "Started.."


	echo SETUP.sh time now: `date +"%T" `
	mongo --host ${MONGODB1}:27017 <<EOF
	var cfg = {
	"_id": "rs0",
	"protocolVersion": 1,
	"version": 1,
	"members": [
	{
	"_id": 0,
	"host": "${MONGODB1}:27017",
	"priority": 2
	},
	{
	"_id": 1,
	"host": "${MONGODB2}:27017",
	"priority": 0
	},
	{
	"_id": 2,
	"host": "${MONGODB3}:27017",
	"priority": 0
	}
	],settings: {chainingAllowed: true}
	};
	rs.initiate(cfg, { force: true });
	rs.reconfig(cfg, { force: true });
	rs.slaveOk();
	db.getMongo().setReadPref('nearest');
	db.getMongo().setSlaveOk();
	EOF
	async function transaction() {
	// Start the transaction.
	const session = await ModelA.startSession();
	session.startTransaction();

	try {
	const options = { session };

	// Try and perform operation on Model.
	const a = await ModelA.create([{ ...args }], options);

	// If the first operation succeeds this next one will get called.
	await ModelB.create([{ ...args }], options);

	// If all succeeded with no errors, commit and end the session.
	await session.commitTransaction();
	session.endSession();
	return a;
	} catch (e) {
	// If any error occured, the whole transaction fails and throws error.
	// Undos changes that may have happened.
	await session.abortTransaction();
	session.endSession();
	throw e;
	}
	}