Redis cluster with Docker Compose
Using Docker Compose to setup a redis cluster with sentinel.
This project was inspired by the project of @mdevilliers
Install Docker and Docker Compose in testing environment.
If you are using Windows, please execute the following command before "git clone" to disable changing the line endings of script files into DOS format:
git config --global core.autocrlf false
The template defines the topology of the Redis cluster:
version: '3.9'
services:
master:
image: redis:latest
container_name: redis-master
slave:
image: redis:latest
container_name: redis-slave
command: redis-server --slaveof redis-master 6379
depends_on:
- master
sentinel:
build:
context: ./sentinel
dockerfile: Dockerfile
container_name: redis-sentinel
environment:
- SENTINEL_DOWN_AFTER=5000
- SENTINEL_FAILOVER=5000
depends_on:
- master
- slave
Notes:
Please make sure the Dockerfile path for the sentinel service and the build context (./sentinel) are correctly specified and refer to your project file structure.
There are following services in the cluster:
The sentinels are configured with a "mymaster" instance with the following properties:
sentinel monitor mymaster redis-master 6379 2
sentinel down-after-milliseconds mymaster 5000
sentinel parallel-syncs mymaster 1
sentinel failover-timeout mymaster 5000
The details could be found in sentinel/sentinel.conf
.
The default values of the environment variables for Sentinel are as following:
Build the sentinel Docker image:
docker compose build .
Start the redis cluster:
docker compose up -d
Check the status of redis cluster:
docker compose ps
The result is:
Name Command State Ports
--------------------------------------------------------------------------------------
rediscluster_master_1 docker-entrypoint.sh redis ... Up 6379/tcp
rediscluster_sentinel_1 docker-entrypoint.sh redis ... Up 26379/tcp, 6379/tcp
rediscluster_slave_1 docker-entrypoint.sh redis ... Up 6379/tcp
Scale out the instance number of sentinel:
docker compose scale sentinel=3
Scale out the instance number of slaves:
docker compose scale slave=2
Check the status of redis cluster:
docker compose ps
The result is:
Name Command State Ports
--------------------------------------------------------------------------------------
rediscluster_master_1 docker-entrypoint.sh redis ... Up 6379/tcp
rediscluster_sentinel_1 docker-entrypoint.sh redis ... Up 26379/tcp, 6379/tcp
rediscluster_sentinel_2 docker-entrypoint.sh redis ... Up 26379/tcp, 6379/tcp
rediscluster_sentinel_3 docker-entrypoint.sh redis ... Up 26379/tcp, 6379/tcp
rediscluster_slave_1 docker-entrypoint.sh redis ... Up 6379/tcp
rediscluster_slave_2 docker-entrypoint.sh redis ... Up 6379/tcp
Execute the test scripts:
./test.sh
to simulate stop and recover the Redis master. And you will see the master is switched to slave automatically.
Or, you can do the test manually to pause/unpause redis server through:
docker pause rediscluster_master_1
docker unpause rediscluster_master_1
And get the sentinel infomation with following commands:
docker exec rediscluster_sentinel_1 redis-cli -p 26379 SENTINEL get-master-addr-by-name mymaster
1: https://github.com/mdevilliers/docker-rediscluster
2: https://registry.hub.docker.com/r/bitnami/redis-sentinel
3: https://docs.docker.com/compose/
4: https://www.docker.com
Apache 2.0 license