In this article, we are going to perform, how to install Redis on CentOS 7. Before we proceed further, Let me give you brief idea about Redis.
Table of Contents
Introduction
Redis is an open source tools, which is used as a database and acts as in-memory data structure store, cache and message broker. Message brokers are building block of message-orianted-middleware(MOM), which transfers, route, respond, invoke and interact with sender/receiver end. It supports different data structures such as string, lists, sorted sets with range queries and etc. In redis, we can configure single data base structure and replication (Master-Slave) too.
Prerequisites
- CentOS 7
- 2 CPU’s, 3GB RAM
- SSH access with sudo privileges
- Open Firewall Port: 6379
Step 1: Install Redis on CentOS
Before installing redis, let’s add EPEL repository and update the YUM package.use below command to update epel,
$ sudo yum install epel-release -y
output:
Running transaction
Installing : epel-release-7-11.noarch 1/1
Verifying : epel-release-7-11.noarch 1/1
Installed:
epel-release.noarch 0:7-11
Complete!
Let’s install redis by using below command.
$ sudo yum install redis -y
output:
Running transaction
Installing : jemalloc-3.6.0-1.el7.x86_64 1/2
Installing : redis-3.2.12-2.el7.x86_64 2/2
Verifying : redis-3.2.12-2.el7.x86_64 1/2
Verifying : jemalloc-3.6.0-1.el7.x86_64 2/2
Installed:
redis.x86_64 0:3.2.12-2.el7
Dependency Installed:
jemalloc.x86_64 0:3.6.0-1.el7
Complete!
To enable the redis service.
$ sudo systemctl enable redis.service
To start the redis service.
$ sudo systemctl start redis.service
To check the status of redis service.
$ sudo systemctl status redis.service
output:
● redis.service - Redis persistent key-value database
Loaded: loaded (/usr/lib/systemd/system/redis.service; enabled; vendor preset: disabled)
Drop-In: /etc/systemd/system/redis.service.d
└─limit.conf
Active: active (running) since Sun 2019-07-21 00:03:36 CDT; 51s ago
Main PID: 31289 (redis-server)
CGroup: /system.slice/redis.service
└─31289 /usr/bin/redis-server 127.0.0.1:6379
Jul 21 00:03:36 fosstechnix systemd[1]: Starting Redis persistent key-value database…
Jul 21 00:03:36 fosstechnix systemd[1]: Started Redis persistent key-value database.
To check redis version, enter below command
$ redis-cli -v
output:
redis-cli 3.0.6
After confirming that redis is running. Let’s run below command.
$ redis-cli
127.0.0.1:6379> ping
PONG
If you get the output as “PONG”. Then its working fine.
Step 2: Configure Redis
Default configuration is located in /etc/redis.conf. Now we will change the configuration to access redis from remote servers, defaultly it has access only to localhost. To enable remote access uncomment and change the bindIP as below.
#bind 127.0.0.1
bind 0.0.0.0
1. Redis as daemon
By default redis does not run as daemon and protection mode is enabled, edit the /etc/redis.conf file and change to daemonize as yes, protected-mode to yes
daemonize yes
protected-mode yes
To take effect of above configuration, restart the redis-server.
$ sudo systemctl restart redis.service
To check redis is listening on port 6379, use below command:
$ netstat -tulpn | grep LISTEN
output:
tcp6 0 0 :::6379 :::* LISTEN -
2. Test Redis using CLI
$ redis-cli
127.0.0.1:6379> ping
PONG
3. To set the value
127.0.0.1:6379> SET <key> <value>
For example:
127.0.0.1:6379> SET 'URL' https://wwww.fosstechnix.com
output:
127.0.0.1:6379> GET 'URL'
"https://wwww.fosstechnix.com"
4.To check keys
127.0.0.1:6379> keys *
Step 3: Secure Redis
By default redis is not secured. In the configuration file /etc/redis.conf, go to SECURITY section and enable authentication
1. Enable Authentication
############ SECURITY #################
#requirepass foobared
Uncomment the above and change password from foobared to <your password> and restart redis-server.
requirepass fosstechnix
$ sudo systemctl restart redis.service
Now let’s test the new configuration. Open redis-cli
$ redis-cli PING
output:
(error) NOAUTH Authentication required.
Now use AUTH and provide your password.
127.0.0.1:6379> AUTH <your password>
127.0.0.1:6379> AUTH fosstechnix
If authentication is successful the output will be OK.
2.Enable firewall
To aceess 6379 port from remote machine we have to add and enable firewall rule.
$ sudo firewall-cmd --permanent --new-zone=redis
$ sudo firewall-cmd --permanent --zone=redis --add-port=6379/tcp .
$ sudo firewall-cmd --permanent --zone=redis --add-source=client_server_private_IP
Step 4: Start, Restart, Stop Redis Server
Use below commands to start,restart and stop redis server using command line,
$ sudo systemctl start redis.server
$ sudo systemctl restart redis.server
$ sudo systemctl stop redis.server
To learn more about Redis. Please refer official documentation.
Conclusion
In this article, we have installed redis on CentOS 7, configured bind-ip and daemonized redis. To protect our data from external users we enabled protection-mode. We created keys, secured the data by setting AUTH and using firewalld we open the port to access form remote servers.
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