Redis (AlmaLinux 8)

Redis (AlmaLinux 8)

  • OS: almalinux 8

Description

Redis is a fast and powerful in-memory key-value data store that allows for quick and easy storage, retrieval, and manipulation of data. Redis can be used as a cache to speed up application performance, or as a secondary data store for additional operations. Redis has a rich feature set, including support for various data types (such as numbers, strings, lists, sets, and hashes), transactional operations, data replication, and many others. Redis is widely used in the software industry and provides many useful tools for managing data.

Software included

Package Version
Redis latest
Docker 3.20.10
Docker compose 2.12.2
containerd.io 1.6.10

Initial start of the service

This application uses Docker to provide faster startup of the underlying software (Redis) and direct use of it. This eliminates the need to familiarize yourself with its specifics in terms of configuration and installation. To start working directly with the application, all you need to do is connect your application that will use Redis by giving it the IP address assigned to your virtual machine and the port that Redis is listening on (described below in default is 6379).

Quick settings and frequently asked questions

  • Logging into the cloud service is done using an SSH key or password that you have specified.
  • Docker is installed as recommended by the official docker documentation.
  • The standard docker and docker compose commands are now available in this application.
  • When the virtual machine is first started, it takes a few minutes before a Docker container containing Redis is started.
  • Redis data is set to be persistent and is located in /opt/redis/data/.
  • By default, Redis runs on all available interfaces on the machine. Redis access port is 6379.

Additional Docker settings

You can configure extra settings as variables for this docker application from it's configuration file /opt/docker-redis/docker-compose.yml.

Note: After changing any of parameters in your configuration file docker-compose.yml you will need to recreate the container. For more information, please see Recreating Docker containers section.

Additional helpful tips

  • If you want to use the redis-cli, you can do it with the quick command docker exec -ti docker-redis-redis-1 redis-cli <COMMAND>.
  • If you often use the redis-cli, you can also make a quick shortcut by adding an alias as follows:
echo "alias redis-cli='docker exec -ti docker-redis-redis-1 redis-cli'" >> ~/.bashrc
source ~/.bashrc

Working with Docker

The organization of this application is entirely done using Docker. In this way, we can provide you with ready-made applications faster. In addition, their configuration is more flexible and quite controllable. To be able to control this application, however, you need to know some basic Docker functionalities and features.

Restarting all services

Restarting the database and the Docker container that contains Redis itself, along with the rest of the software, can be done in two ways:

  1. By restarting the entire virtual machine
  2. Restarting the Docker containers, which is the faster option. To do this, access your machine via SSH, and run the following commands:
sudo su -
cd /opt/docker-redis/
docker compose restart

Recreating Docker containers

Recreation of a docker container may be necessary if you've changed the configuration inside the docker-compose.yml file. If there are changes, please follow these steps:

cd /opt/docker-redis/
docker compose stop
docker compose up -d

Checking the status of the Docker application

To check, you need to run the following commands:

sudo su -
docker ps -a

Please pay attention to the STATUS column. It should show how long the service has been running, for example Up X minutes. If the status is Restarting then you need to check what is wrong with the application. In such a case, you can check by following the application logs as follows:

  1. Get the application name that you can see in the NAMES column from the output of the docker ps -a command. View the logs with the docker logs <NAME> command, where is the name of the container.

Changing settings

The settings in section Additional Docker settings can be set in the docker-compose.yml file. The path to it is described again in this section. To change a setting, open the configuration file and note the environment section under redis. Each configuration option must be described on a new line with a dash in front, as in the following example:

    environment:
      - ALLOW_EMPTY_PASSWORD=yes

Please note that the correct indentation (number of spaces) must also be observed, as this is important for yaml configuration files.