cusspvz/redis repository overview

⁠redis.docker

[WIP] WORK IN PROGRESS Please don't pull this repo until clustering methods are solved!

redis container with auto-clustering capabilities (kind of super powers)!

This image relies on two main variables for clustering: CLUSTER_NAME and CLUSTER_HOSTS.

⁠Environment variables

• CLUSTER_NAME - You should give a name to your cluster and place it here.

• RUNNING_MODE - This variable could be set with values: cluster and standalone.

  • Defaults to cluster if CLUSTER_NAME is set and non-empty, otherwise it will always default to cluster.

• CLUSTER_HOSTS - Here you should place a cluster fqdn or IP plus port, separated.

  • If empty, or unable to connect to hosts, container will act as the first one on the cluster.
  • Defaults to (empty string).
  • Examples:
    • 10.0.0.10:4423,10.0.0.11:4423,10.0.0.12:4423
    • local.skydns.redis.clustername:1234

• CLUSTER_CONNECT_TIMEOUT - seconds it should wait for each host before elects itself as the first one on the cluster.

  • Defaults to 5.

• CLUSTER_REPLICAS - number of replica servers

  • Defaults to 1.

• PORT - port where redis should be listening on.

  • Defaults to 6379.

• LOG_LEVEL - log level to be specified on servers configs.

  • Defaults to notice;

⁠Container startup explained

• RUNNING_MODE is set as cluster
• Container tries to ping CLUSTER_HOSTS
  • if any of them respond to ping, RUNNING_MODE is set to cluster
• redis configs are updated and service is started
• if RUNNING_MODE is cluster
  • redis-sentinel configs are updated and service is started
  • redis/tool/cluster

⁠Running on CoreOS

I've added [email protected] fleet unit file on this repo in case you want to use with CoreOS. This unit relies on skydns for service discovery, so it will only work with it, sorry. :)

Submit this unit into CoreOS before starting launching instances:

fleetctl submit [email protected]

⁠Launching an instance

We use unit instance id variable to pass also CLUSTER_NAME configuration.

# redis@{CLUSTER_NAME}:{ID}

# Launching 4 nodes cluster for gitlab service.
fleetctl launch redis@gitlab:1;
fleetctl launch redis@gitlab:2;
fleetctl launch redis@gitlab:3;
fleetctl launch redis@gitlab:4;

# Now, if your dig your domain, it should return all instances:
dig @sky.dns.srv.ip gitlab.redis.skydns.local;

⁠Developing

⁠Building image

docker build -t cusspvz/redis .