How to Run Redis with Docker Compose. Relational databases are used in most IT projects. Some specific project requires to use NoSQL databases. One of the most popular in memory data storage systems on the market is Redis that stands for Remote Dictionary Server.
What is Redis Server
Redis is a free and open source (BSD license) server that is both a memory and key value store.
- The memory database stores all data directly in the memory allowing very fast access times, even for large amounts of unstructured data.
- Key value store are databases that offer high performance and are easy to scale due to their simple structure.
Redis server stores data in the memory and to limit the risk of losing all the data Redis copies all the data regularly to a backup hard drive or save all the commands needed for reconstruction in a log file.
These data structures include strings, hashes, lists, sets and sorted sets with range queries as well as Hyperloglogs, bitmaps and geographic indexes.
Streaming is also supported. For high availability, Redis enables Redis Sentinel and automated partitioning with Redis Cluster and provides replication that is built in, Lua scripting, LRU eviction, transactions and different levels of persistence on disk.
What is Docker Compose?
Docker Compose is a tool that allows you to centrally manage the deployments of many different Docker containers.
Docker container is a unit of software that packages up code and all its dependencies to allow the application to run quickly and reliably from one computing environment to another. For launching multiple Docker containers, a YAML file is used by Compose to initialize services for the app. Creating and launching all of the functions is as simple as issuing a single command when configuration is complete.
How to Run Redis with Docker Compose , how to construct a Docker container and how to deal with different issues that may arise, are all covered in this article.
How to Run Redis with Docker Compose
Prerequisites
In order for the Redis Container to work, Docker has to be set up on the host system or server. The “docker -v” command may be used to verify the current Docker engine version installed.
Step 1 — Use Docker pull to download the Redis image
We will pursue the recommended way which is to use the Docker pull command to obtain the prebuilt Redis Docker image from the Docker Hub Registry.
We will download the image by using the command below:
$ docker pull bitnami/redis:latest
Step 2 — Persisting your database
Upon removal of the container all of your stored data can be lost, leading to recreation of the database every time the image is run. Mount a volume that will survive even after the container is removed to prevent losing data.
To achieve persistence a directory will be mounted at the /bitnami path.
Do this by proceeding to make changes to the docker-compose.yml file present in the linked repository, in the following way:
services:
redis:
...
volumes:
- /path/to/redis-persistence:/bitnami/redis/data
...
Step 3 — Use Docker Compose
By default, if a network name is not provided, a new network is created by Docker compose which connects all deployed services to it. However, a new bridge network called “app-network” will be expressly defined. If you wish to connect to the Redis(TM) server from your own custom application image, use the service name “myapplication” in the following code snippet.
version: '2'
networks:
app-network:
driver: bridge
services:
redis:
image: 'bitnami/redis:latest'
environment:
- ALLOW_EMPTY_PASSWORD=yes
networks:
- app-network
myapplication:
image: 'YOUR_APPLICATION_IMAGE'
networks:
- app-tier
Next, we will launch the containers using:
$ docker-compose up -d
Step 4 — Disable Redis(TM) commands
Some commands may need to be disabled for security concerns. The following environment variable may be used to initialise them.
Proceed to make changes to the docker-compose.yml file present in the linked repository, as show below:
services:
redis:
...
environment:
- REDIS_DISABLE_COMMANDS=FLUSHDB,FLUSHALL,CONFIG
...
Step 5 — Pass extra command-line flags
The run.sh script may be used to provide additional command-line parameters to the redis service command.
Proceed to make changes to the docker-compose.yml file present in the linked repository as show below:
services:
redis:
...
environment:
- ALLOW_EMPTY_PASSWORD=yes
command: /opt/bitnami/scripts/redis/run.sh --maxmemory 100mb
...
Step 6 -Setup server password on first run
The Redis server password will be set to the value of REDIS_PASSWORD (or the content of the file provided in REDIS_PASSWORD_FILE) if the REDIS_PASSWORD environment variable is passed when executing the image for the first time
Proceed to make changes to the docker-compose.yml file present in the linked repository as shown below:
services:
redis:
...
environment:
- REDIS_PASSWORD=password123
...
Step 7 — Allow empty passwords
How to Run Redis with Docker ComposeIf you want to use the Redis(TM) image, you must set all of the passwords. By setting the environment variable, ALLOW_EMPTY_PASSWORD=yes, empty passwords will be enabled and this feature will then work..
Proceed to make changes to the docker-compose.yml file present in the linked repository, as shown below:
services:
redis:
...
environment:
- ALLOW_EMPTY_PASSWORD=yes
...
Step 8 — Disable AOF persistence
Redis(TM) has a variety of persistence options. The AOF (Append Only File) method is used by default in this picture. Should you need to change this behaviour, setting By setting REDIS_AOF_ENABLED=no this feature of this environment variable can be disabled in order to modify the behavior mentioned earlier.
Proceed to make changes to the docker-compose.yml file present in the linked repository, as shown below:
services:
redis:
...
environment:
- REDIS_AOF_ENABLED=no
...
Step 9 — Set up a standalone instance
On port 6379, Redis(TM) is launched by default in this image in standalone mode. Setting the REDIS_PORT_NUMBER environment variable will update the port number if need be.
Proceed to make changes to the docker-compose.yml file present in the linked repository, as shown below:
services:
redis:
...
environment:
- REDIS_PORT_NUMBER=7000
...
ports:
- '7000:7000'
....
Step 10 — Create the replication master
First we need to initialise the Redis master by using following commands:
$ docker run --name redis-master \
-e REDIS_REPLICATION_MODE=master \
-e REDIS_PASSWORD=masterpassword123 \
bitnami/redis:latest
Step 11 — Create the masternode
With Docker Compose the master node can be setup using:
version: '2'
services:
redis-master:
image: 'bitnami/redis:latest'
ports:
- '6379'
environment:
- REDIS_REPLICATION_MODE=master
- REDIS_PASSWORD=my_master_password
volumes:
- '/path/to/redis-persistence:/bitnami'
redis-replica:
image: 'bitnami/redis:latest'
ports:
- '6379'
depends_on:
- redis-master
environment:
- REDIS_REPLICATION_MODE=slave
- REDIS_MASTER_HOST=redis-master
- REDIS_MASTER_PORT_NUMBER=6379
- REDIS_MASTER_PASSWORD=my_master_password
- REDIS_PASSWORD=my_replica_password
Scale the number of replicas up by 3 using the following command:
$ docker-compose up --detach --scale redis-master=1 --scale redis-secondary=3
You can use the command above to scale down as well. Although make note that master node shouldnt be scaled up or down as at a time only one master node should be running.
Step 12 — Secure Redis(TM) traffic
As soon as you switch on TLS, all non-TLS communication is disabled. Non-TLS traffic may be enabled by changing the value of REDIS_TLS PORT to a port other than 0.
Proceed to make changes to the docker-compose.yml file present in the linked repository, as shown below:
services:
redis:
...
environment:
...
- REDIS_TLS_ENABLED=yes
- REDIS_TLS_CERT_FILE=/opt/bitnami/redis/certs/redis.crt
- REDIS_TLS_KEY_FILE=/opt/bitnami/redis/certs/redis.key
- REDIS_TLS_CA_FILE=/opt/bitnami/redis/certs/redisCA.crt
...
volumes:
- /path/to/certs:/opt/bitnami/redis/certs
- /path/to/redis-persistence:/bitnami/redis/data
Step 13 — Configuration file
Proceed to make changes to the docker-compose.yml file present in the linked repository, as shown below:
services:
redis:
...
volumes:
- /path/to/your_redis.conf:/opt/bitnami/redis/mounted-etc/redis.conf
- /path/to/redis-persistence:/bitnami/redis/data
..
Step 14 — Logging
To view the logs on stdout that Redis Docker image sends our container run the following command:
$ docker-compose logs redis
Step 15 — Maintenance
The last step of how to Run Redis with Docker Compose is maintenance. Bitnami provides up to date versions of Redis(TM), including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.
1) To obtain the updated image, run the following command:
$ docker pull bitnami/redis:latest
2) Next we need to stop the container:
We will do the stopping by running the command below:
$ docker-compose stop redis
3) Now we will proceed to remove the container that is currently running by using the following command:
$ docker-compose rm -v redis
4) Now it’s time to run the new image by deploying the following command:
$ docker-compose up redis
How to Run Redis with Docker Compose Conclusion
This article demonstrated how to use Docker Compose to run Redis. Error handling, stopping the container, running Redis using Compose and creating several additional files were also showed in this tutorial.
We hope this article was informative and provided a step by step guide which was easy to follow and which you were able to successfully implement. Thank you for reading through!
