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dplesa
dplesa

Reputation: 1425

OpenShift and persistent Redis config

I have successfully deployed Redis (persistent) image on my OpenShift installation. Now I want to persist the Redis configuration, and I have followed this instructions.

However, the Redis is started with this command inside a container: /opt/rh/rh-redis32/root/usr/bin/redis-server *:6379

I see that it should be started with the first argument as a path to the configuration file in order to configure itself on startup.

How can I achieve this in OpenShift?

Upvotes: 0

Views: 4206

Answers (2)

dplesa
dplesa

Reputation: 1425

I solved this issue with run commands specified in deployment config:

 containers:
        - name: redis
          image: >-
            centos/redis-32-centos7@sha256:7289ff47dd1c5bd24e6eefaf18cfbacf5ad68c0768f1b727a79c026bbef5a038
          command:
            - /opt/rh/rh-redis32/root/usr/bin/redis-server
            - /redis-master/redis.conf

Since this completly overrides default startup behaviof of the provided Docker image I had to add dir and requirepass configs to my config map:

dir /var/lib/redis/data
requirepass srid
maxmemory 2mb
maxmemory-policy allkeys-lru

Upvotes: 3

wilsonW
wilsonW

Reputation: 374

I'm not sure you are supposed to try that kind of stuff ;) But you can use that workaround (not using it in production could be a good idea)

First of all create download your config file : 

$ curl -o redis.conf http://download.redis.io/redis-stable/redis.conf
$ curl -o run-redis https://raw.githubusercontent.com/sclorg/redis-container/master/3.2/root/usr/bin/run-redis

Then edit redis.conf and change the values you want 

$ vi redis.conf

Now edit run-redis and replace last line with :

exec ${REDIS_PREFIX}/bin/redis-server /tmp/redis.conf --daemonize no "$@" 2>&1

$ vi run-redis

Now you have to create a configMap from these files :

$ oc create configmap myredisconfig --from-file=redis.conf --from-file=run-redis

And mount the configmap into the container: 

$ oc volume dc/redis --add --name=conf --type=configmap --configmap-name=myredisconfig --mount-path=/tmp

Finally edit redis dc:

Let's suppose I changed port 6379 to port 5000 in my redis.conf

  • Add spec.template.spec.containers.command : 
spec:
  containers:
  - command:
    - /tmp/run-redis
  • Change spec.template.spec.volumes.configMap.defaultMode to 444
  - configMap:
      defaultMode: 444
      name: myredisconfig
    name: conf
  • If you are using an image with healthchecks, don't forget to change ports to check with your new one, or it will fail (spec.template.spec.containers.livenessProbe.tcpSocket.port) 
    livenessProbe:
      failureThreshold: 3
      initialDelaySeconds: 30
      periodSeconds: 10
      successThreshold: 1
      tcpSocket:
        port: 5000
  • Now change the readinessProbe adding "-p $PORT" in test command : 
    readinessProbe:
      exec:
        command:
        - /bin/sh
        - -i
        - -c
        - test "$(redis-cli -h 127.0.0.1 -p 5000 -a $REDIS_PASSWORD ping)" == "PONG"
  • Don't forget to change ContainerPort: 6379 with you new port, or you won't be able to expose it to services & routes (spec.template.spec.ports)
 ports:
    - containerPort: 5000
      protocol: TCP

$ oc edit dc redis

Hope it helped :)

Upvotes: 0

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