What is Redis-Cluster?

Redis is an advanced key-value cache and store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, sorted sets, bitmaps and hyperloglogs.

Redis.io

TL;DR

$ docker run --name redis-cluster -e ALLOW_EMPTY_PASSWORD=yes bitnami/redis-cluster:latest

Docker Compose

$ curl -sSL https://raw.githubusercontent.com/bitnami/bitnami-docker-redis-cluster/master/docker-compose.yml > docker-compose.yml
$ docker-compose up -d

Why use Bitnami Images?

• Bitnami closely tracks upstream source changes and promptly publishes new versions of this image using our automated systems.
• With Bitnami images the latest bug fixes and features are available as soon as possible.
• Bitnami containers, virtual machines and cloud images use the same components and configuration approach - making it easy to switch between formats based on your project needs.
• All our images are based on minideb a minimalist Debian based container image which gives you a small base container image and the familiarity of a leading Linux distribution.
• All Bitnami images available in Docker Hub are signed with Docker Content Trust (DCT). You can use DOCKER_CONTENT_TRUST=1 to verify the integrity of the images.
• Bitnami container images are released daily with the latest distribution packages available.

This CVE scan report contains a security report with all open CVEs. To get the list of actionable security issues, find the "latest" tag, click the vulnerability report link under the corresponding "Security scan" field and then select the "Only show fixable" filter on the next page.

How to deploy Redis-Cluster in Kubernetes?

Deploying Bitnami applications as Helm Charts is the easiest way to get started with our applications on Kubernetes. Read more about the installation in the Bitnami Redis-Cluster Chart GitHub repository.

Bitnami containers can be used with Kubeapps for deployment and management of Helm Charts in clusters.

Supported tags and respective Dockerfile links

Learn more about the Bitnami tagging policy and the difference between rolling tags and immutable tags in our documentation page.

• 6.0, 6.0-debian-10, 6.0.9, 6.0.9-debian-10-r33, latest (6.0/debian-10/Dockerfile)
• 5.0, 5.0-debian-10, 5.0.10, 5.0.10-debian-10-r35 (5.0/debian-10/Dockerfile)

Subscribe to project updates by watching the bitnami/redis-cluster GitHub repo.

Get this image

The recommended way to get the Bitnami Redis-Cluster Docker Image is to pull the prebuilt image from the Docker Hub Registry.

$ docker pull bitnami/redis-cluster:latest

To use a specific version, you can pull a versioned tag. You can view the list of available versions in the Docker Hub Registry.

$ docker pull bitnami/redis-cluster:[TAG]

If you wish, you can also build the image yourself.

$ docker build -t bitnami/redis-cluster:latest 'https://github.com/bitnami/bitnami-docker-redis-cluster.git#master:6.0/debian-10'

Persisting your application

If you remove the container all your data will be lost, and the next time you run the image the database will be reinitialized. To avoid this loss of data, you should mount a volume that will persist even after the container is removed.

For persistence you should mount a directory at the /bitnami path. If the mounted directory is empty, it will be initialized on the first run.

$ docker run \
    -e ALLOW_EMPTY_PASSWORD=yes
    -v /path/to/redis-cluster-persistence:/bitnami \
    bitnami/redis-cluster:latest

You can also do this with a minor change to the docker-compose.yml file present in this repository:

redis-cluster:
  ...
  volumes:
    - /path/to/redis-cluster-persistence:/bitnami
  ...

Connecting to other containers

Using Docker container networking, a different server running inside a container can easily be accessed by your application containers and vice-versa.

Containers attached to the same network can communicate with each other using the container name as the hostname.

Using the Command Line

Step 1: Create a network

$ docker network create redis-cluster-network --driver bridge

Step 2: Launch the Redis-Cluster container within your network

Use the --network <NETWORK> argument to the docker run command to attach the container to the redis-cluster-network network.

$ docker run -e ALLOW_EMPTY_PASSWORD=yes --name redis-cluster-node1 --network redis-cluster-network bitnami/redis-cluster:latest

Step 3: Run another containers

We can launch another containers using the same flag (--network NETWORK) in the docker run command. If you also set a name to your container, you will be able to use it as hostname in your network.

Configuration

Configuration file

The image looks for configurations in /opt/bitnami/redis/mounted-etc/redis.conf. You can overwrite the redis.conf file using your own custom configuration file.

$ docker run --name redis \
    -e ALLOW_EMPTY_PASSWORD=yes \
    -v /path/to/your_redis.conf:/opt/bitnami/redis/mounted-etc/redis.conf \
    -v /path/to/redis-data-persistence:/bitnami/redis/data \
    bitnami/redis-cluster:latest

Alternatively, modify the docker-compose.yml file present in this repository:

services:
  redis-node-0:
  ...
    volumes:
      - /path/to/your_redis.conf:/opt/bitnami/redis/mounted-etc/redis.conf
      - /path/to/redis-persistence:/bitnami/redis/data
  ...

Refer to the Redis configuration manual for the complete list of configuration options.

The following env vars are supported for this container:

Name	Description
REDIS_DISABLE_COMMANDS	Disables the specified Redis commands
REDIS_PORT	Set the Redis port. Default=: 6379
REDIS_PASSWORD	Set the Redis password. Default: bitnami
ALLOW_EMPTY_PASSWORD	Enables access without password
REDIS_DNS_RETRIES	Number of retries to get the IPs of the provided REDIS_NODES. It will wait 5 seconds between retries
REDISCLI_AUTH	Provide the same value as the configured REDIS_PASSWORD for the redis-cli tool to authenticate
REDIS_CLUSTER_CREATOR	Set to yes if the container will be the one on charge of initialize the cluster. This node will not be part of the cluster, it will complete the execution after the initialization.
REDIS_CLUSTER_REPLICAS	Number of replicas for every master that the cluster will have.
REDIS_NODES	String delimited by spaces containing the hostnames of all of the nodes that will be part of the cluster
REDIS_CLUSTER_ANNOUNCE_IP	IP that the node should announce, used for non dynamic ip environents
REDIS_CLUSTER_DYNAMIC_IPS	Set to no if your Redis cluster will be created with statical IPs. Default: yes
REDIS_TLS_ENABLED	Whether to enable TLS for traffic or not. Defaults to no.
REDIS_TLS_PORT	Port used for TLS secure traffic. Defaults to 6379.
REDIS_TLS_CERT_FILE	File containing the certificate file for the TSL traffic. No defaults.
REDIS_TLS_KEY_FILE	File containing the key for certificate. No defaults.
REDIS_TLS_CA_FILE	File containing the CA of the certificate. No defaults.
REDIS_TLS_DH_PARAMS_FILE	File containing DH params (in order to support DH based ciphers). No defaults.
REDIS_TLS_AUTH_CLIENTS	Whether to require clients to authenticate or not. Defaults to yes.
REDIS_CLUSTER_SLEEP_BEFORE_DNS_LOOKUP	Number of seconds to wait before initializing the cluster. Set this to a higher value if you sometimes have issues with initial cluster creation. Defaults to 0.
REDIS_CLUSTER_DNS_LOOKUP_RETRIES	Number of retries for the node's DNS lookup during the initial cluster creation. Defaults to 5.
REDIS_CLUSTER_DNS_LOOKUP_SLEEP	Number of seconds to wait between each node's DNS lookup during the initial cluster creation. Defaults to 1.

Once all the Redis nodes are running you need to execute command like the following to initiate the cluster:

redis-cli --cluster create node1:port node2:port --cluster-replicas 1 --cluster-yes

Where you can add all the node:port that you want. The --cluster-replicas parameters indicates how many replicas you want to have for every master.

Cluster Initialization Troubleshooting

Depending on the environment you're deploying into, you might run into issues where the cluster initialization is not completing successfully. One of the issue is related to the DNS lookup of the redis nodes performed during cluster initialization. By default, this DNS lookup is performed as soon as all the redis nodes reply to a successful ping. However, in some environments such as Kubernetes, it can help to wait some time before performing this DNS lookup in order to prevent getting stale records. To this end, you can increase REDIS_CLUSTER_SLEEP_BEFORE_DNS_LOOKUP to a value around 30 which has been found to be good in most cases. You can check the discussion regarding this here.

Securing Redis Cluster traffic

Starting with version 6, Redis adds the support for SSL/TLS connections. Should you desire to enable this optional feature, you may use the aforementioned REDIS_TLS_* enviroment variables to configure the application.

When enabling TLS, conventional standard traffic is disabled by default. However this new feature is not mutually exclusive, which means it is possible to listen to both TLS and non-TLS connection simultaneously. To enable non-TLS traffic, set REDIS_TLS_PORT to another port different than 0.

1. Using docker run

   $ docker run --name redis-cluster \
       -v /path/to/certs:/opt/bitnami/redis/certs \
       -v /path/to/redis-cluster-persistence:/bitnami \
       -e ALLOW_EMPTY_PASSWORD=yes \
       -e REDIS_TLS_ENABLED=yes \
       -e REDIS_TLS_CERT_FILE=/opt/bitnami/redis/certs/redis.crt \
       -e REDIS_TLS_KEY_FILE=/opt/bitnami/redis/certs/redis.key \
       -e REDIS_TLS_CA_FILE=/opt/bitnami/redis/certs/redisCA.crt \
       bitnami/redis-cluster:latest

2. Modifying the docker-compose.yml file present in this repository:

     redis-cluster:
     ...
       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
       ...
     ...

Alternatively, you may also provide with this configuration in your custom configuration file.

Logging

The Bitnami Redis-Cluster Docker image sends the container logs to stdout. To view the logs:

$ docker logs redis-cluster

You can configure the containers logging driver using the --log-driver option if you wish to consume the container logs differently. In the default configuration docker uses the json-file driver.

Maintenance

Upgrade this image

Bitnami provides up-to-date versions of Redis-Cluster, including security patches, soon after they are made upstream. We recommend that you follow these steps to upgrade your container.

Step 1: Get the updated image

$ docker pull bitnami/redis-cluster:latest

Step 2: Stop the running container

Stop the currently running container using the command

$ docker stop redis-cluster

Step 3: Remove the currently running container

$ docker rm -v redis-cluster

Step 4: Run the new image

Re-create your container from the new image.

$ docker run --name redis-cluster bitnami/redis-cluster:latest

Contributing

We'd love for you to contribute to this container. You can request new features by creating an issue, or submit a pull request with your contribution.

Issues

If you encountered a problem running this container, you can file an issue. For us to provide better support, be sure to include the following information in your issue:

• Host OS and version
• Docker version (docker version)
• Output of docker info
• Version of this container
• The command you used to run the container, and any relevant output you saw (masking any sensitive information)

License

Copyright (c) 2020 Bitnami

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.