Build a mongodb replication set in docker to provide data redundancy and high availability, provide a certain degree of fault tolerance, and prevent the loss of a single database.

Create the master node

Create the mount directory and enter

mkdir -p /home/docker/test/node-p
cd /home/docker/test/node-p

Create data mount directory

mkdir db

Generate mongodb-keyfile file

openssl rand -base64 741 > mongodb-keyfile

Set file permissions

sudo chmod 600 mongodb-keyfile
sudo chown 999 mongodb-keyfile

Start the master node

docker run -d --name node-p -p 27027:27017 \
  -v /home/docker/test/node-p/db:/data/db \
  -v /home/docker/test/node-p/mongodb-keyfile:/opt/mongodb-keyfile \
  -v /etc/localtime:/etc/localtimmke:ro \
  --privileged=true \
  --restart=always \
  -e MONGO_INITDB_ROOT_USERNAME=root \
  -e MONGO_INITDB_ROOT_PASSWORD=mfweah0rGxyOH49A \
  mongo:4.2.6 --auth --keyFile /opt/mongodb-keyfile --oplogSize 102400 --wiredTigerCacheSizeGB 16 --replSet "cmdhelp"

Enter the main node container

docker exec -it node-p /bin/bash

Verify permissions

mongo
use admin
db.auth('root','mfweah0rGxyOH49A')

Initialize the current node, configure the weight to 5

rs.initiate({ _id:"cmdhelp",members:[{_id:0,host:"192.168.2.234:27027", priority: 5}]})

Create arbitration node

Create the mount directory and enter

mkdir -p /home/docker/test/node-m
cd /home/docker/test/node-m

Create data mount directory

mkdir db

Copy the mongodb-keyfile file of the master node (copy according to your actual path)

scp /home/docker/test/node-p/mongodb-keyfile .

Set file permissions

sudo chmod 600 mongodb-keyfile
sudo chown 999 mongodb-keyfile

Start the arbitration node

docker run -d --name node-m -p 27028:27017 \
  -v /home/docker/test/node-m/db:/data/db \
  -v /home/docker/test/node-m/mongodb-keyfile:/opt/mongodb-keyfile \
  -v /etc/localtime:/etc/localtimmke:ro \
  --privileged=true \
  --restart=always \
  -e MONGO_INITDB_ROOT_USERNAME=root \
  -e MONGO_INITDB_ROOT_PASSWORD=mfweah0rGxyOH49A \
  mongo:4.2.6 --auth --keyFile /opt/mongodb-keyfile --oplogSize 102400 --wiredTigerCacheSizeGB 1 --replSet "cmdhelp"

Create slave node

Create the mount directory and enter

mkdir -p /home/docker/test/node-s
cd /home/docker/test/node-s

Create data mount directory

mkdir db

Copy the mongodb-keyfile file of the master node (copy according to your actual path)

scp /home/docker/test/node-p/mongodb-keyfile .

Set file permissions

sudo chmod 600 mongodb-keyfile
sudo chown 999 mongodb-keyfile

Start slave node

docker run -d --name node-s -p 27029:27017 \
  -v /home/docker/test/node-s/db:/data/db \
  -v /home/docker/test/node-s/mongodb-keyfile:/opt/mongodb-keyfile \
  -v /etc/localtime:/etc/localtimmke:ro \
  --privileged=true \
  --restart=always \
  -e MONGO_INITDB_ROOT_USERNAME=root \
  -e MONGO_INITDB_ROOT_PASSWORD=mfweah0rGxyOH49A \
  mongo:4.2.6 --auth --keyFile /opt/mongodb-keyfile --oplogSize 102400 --wiredTigerCacheSizeGB 16 --replSet "cmdhelp"

Configure arbitration node and slave node

Enter the main node container

docker exec -it node-p /bin/bash

Management authority verification

mongo
use admin
db.auth('root','mfweah0rGxyOH49A')

Configure arbitration node

rs.addArb("192.168.2.234:27028")

Configure slave node

rs.add("192.168.2.234:27029")

View node status

rs.status()

ps:

mongodb-keyfile needs to be maintained and permissions need to be configured
This test is on a single machine, and multiple machines can replace the corresponding ip

The most complete mongodb builds a replication set in a docker container