MongoDB-Replica-Set-

Deploy a MongoDB Replica Set using Docker

Create three docker-machine

1. Install virtualbox on Mac

2. Create a machine called manager1 using virtualbox as the virtualization provider

docker-machine create -d virtualbox manager1

Docker is up and running!

docker-machine env manager1

export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://192.168.99.100:2376"
export DOCKER_CERT_PATH="/Users/developer/.docker/machine/machines/manager1"
export DOCKER_MACHINE_NAME="manager1"

3. Create the other two docker-machines as worker

docker-machine create -d virtualbox worker1
docker-machine create -d virtualbox worker2

docker-machine env worker1

export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://192.168.99.101:2376"
export DOCKER_CERT_PATH="/Users/developer/.docker/machine/machines/worker1"
export DOCKER_MACHINE_NAME="worker1"

docker-machine env worker2

export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://192.168.99.102:2376"
export DOCKER_CERT_PATH="/Users/developer/.docker/machine/machines/worker2"
export DOCKER_MACHINE_NAME="worker2"

docker-machine ls

NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
manager1 - virtualbox Running tcp://192.168.99.100:2376 v18.09.6
worker1 - virtualbox Running tcp://192.168.99.101:2376 v18.09.6
worker2 - virtualbox Running tcp://192.168.99.102:2376 v18.09.6

Attached our volume created to start our first mongo container and set the configurations.

Start the mongodb configuration,

4. Position in the first machine to run the next command:

eval `docker-machine env manager1`

5. Configuration of master node of MongoDB

docker volume create --name mongo_storage

docker run --name mongoNode1 \
-v mongo_storage:/data \
-d mongo \
--smallfiles

6. Create the key file. The content of the keyfile must be the same for all members of the replica set.

openssl rand -base64 741 > mongo-keyfile
chmod 600 mongo-keyfile

7. Create the folders where is going to hold the data, keyfile and configurations inside the mongo_storage volume

docker exec mongoNode1 bash -c 'mkdir /data/keyfile /data/admin'

8. Create the admin.js file, admin users for mongoDB.

9. Create the replica.js file, to init the replica set.

10. Pass the three files to the container.

docker cp admin.js mongoNode1:/data/admin/
docker cp replica.js mongoNode1:/data/admin/
docker cp mongo-keyfile mongoNode1:/data/keyfile/

11. change folder owner to the user container

docker exec mongoNode1 bash -c 'chown -R mongodb:mongodb /data'

12. Create an env file to set our users and passwords.

13. Remove the container and start a new one with the replica set and authentication parameters.

docker rm -f mongoNode1
// now lets start our container with authentication 
docker run --name mongoNode1 --hostname mongoNode1 \
-v mongo_storage:/data \
--env-file env \
--add-host manager1:192.168.99.100 \
--add-host worker1:192.168.99.101 \
--add-host worker2:192.168.99.102 \
-p 27017:27017 \
-d mongo --smallfiles \
--keyFile /data/keyfile/mongo-keyfile \
--replSet 'rs1' \
--storageEngine wiredTiger \
--port 27017

--env-file reads an env file and sets environment variables inside the container.
--add-host flag adds entries into the docker container’s /etc/hosts file so we can use hostnames instead of IP addresses. Here we are mapping our 3 docker-machines that we have created before.
--keyFile this flag is for telling mongo where is the mongo-keyfile.
--replSet this flag is for setting the name of the replica set.
--storageEngine this flag is for setting the engine of the mongoDB

14. Start the replica set

docker exec mongoNode1 bash -c 'mongo < /data/admin/replica.js'

MongoDB shell version v4.0.9
connecting to: mongodb://127.0.0.1:27017/?gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("508f507e-5f28-4395-88c6-d5a1b54faa7a") }
MongoDB server version: 4.0.9
{ "ok" : 1 }
bye

15. Create the admin users with the following command

docker exec mongoNode1 bash -c 'mongo < /data/admin/admin.js'

MongoDB shell version v4.0.9connecting to: mongodb://127.0.0.1:27017/?gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("1572d671-6595-4e7f-995e-16f93287a8ee") }
MongoDB server version: 4.0.9
admin
Successfully added user: {
"user" : "admin",
"roles" : [
{
"role" : "userAdminAnyDatabase",
"db" : "admin" }
]
}
1
Successfully added user: {
"user" : "replicaAdmin",
"roles" : [
{
"role" : "clusterAdmin",
"db" : "admin"
}
]
}
bye

16. Get in to the replica run the following command:

docker exec -it mongoNode1 bash -c 'mongo -u $MONGO_REPLICA_ADMIN -p $MONGO_PASS_REPLICA --eval "rs.status()" --authenticationDatabase "admin"'

MongoDB shell version v4.0.9 connecting to: mongodb://127.0.0.1:27017/?authSource=admin&gssapiServiceName=mongodb Implicit session: session { "id" : UUID("f72f3fc1-cd93-4d3f-b061-ce38d9d1c19d") } MongoDB server version: 4.0.9 { "set" : "rs1", "date" : ISODate("2019-05-18T01:29:24.448Z"), "myState" : 1, "term" : NumberLong(1), "syncingTo" : "", "syncSourceHost" : "", "syncSourceId" : -1, "heartbeatIntervalMillis" : NumberLong(2000), "optimes" : { "lastCommittedOpTime" : { "ts" : Timestamp(1558142954, 1), "t" : NumberLong(1) }, "readConcernMajorityOpTime" : { "ts" : Timestamp(1558142954, 1), "t" : NumberLong(1) }, "appliedOpTime" : { "ts" : Timestamp(1558142954, 1), "t" : NumberLong(1) }, "durableOpTime" : { "ts" : Timestamp(1558142954, 1), "t" : NumberLong(1) } }, "lastStableCheckpointTimestamp" : Timestamp(1558142944, 1), "members" : [ { "_id" : 0, "name" : "manager1:27017", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 502, "optime" : { "ts" : Timestamp(1558142954, 1), "t" : NumberLong(1) }, "optimeDate" : ISODate("2019-05-18T01:29:14Z"), "syncingTo" : "", "syncSourceHost" : "", "syncSourceId" : -1, "infoMessage" : "", "electionTime" : Timestamp(1558142533, 2), "electionDate" : ISODate("2019-05-18T01:22:13Z"), "configVersion" : 1, "self" : true, "lastHeartbeatMessage" : "" } ], "ok" : 1, "operationTime" : Timestamp(1558142954, 1), "$clusterTime" : { "clusterTime" : Timestamp(1558142954, 1), "signature" : { "hash" : BinData(0,"hBRoJb/8N/78HZhxplUhw9YtIZE="), "keyId" : NumberLong("6692171226036568066") } } }

Adding 2 more mongo node containers

Repeat almost all the steps made for mongoNode1, let’s make a script that runs all of our commands for us.

17. Create a file called create-replica-set.sh
    Execute the script that will configure everything for us except creating three docker-machine

bash < create-replica-set.sh

18. Remvoing all containers and docker volume from docke-machine

bash < reset-docker-machines.sh