Redis is available as an add-on and is backed by AWS Elasticache. Redis instances are designed to be shared across multiple apps in a cluster, but a cluster may have multiple Redis instances. If you wish to isolate a single app to a single Redis instance, you can do that too.
Creating a Redis cluster
First you must setup Redis in your AppPack Cluster. This can be done with
apppack create redis.
apppack create redis my-redis
This command requires manually configured AWS credentials.
Enabling the Redis add-on for your application
During app creation, you'll be asked if you'd like to enable the Redis add-on and if so, which Redis cluster to use. Only Redis instances within the app's AppPack cluster will be available as options.
Enabling the Redis add-on will create a dedicated Redis user within the Redis instance and assign permissions to a specific namespace within Redis.
Destroying the application does not currently destroy any data in Redis. It is setup as a least recently used (LRU) cache, so unused keys will expire as needed. If data security or privacy is an issue, you should manually delete any keys that might be left over.
The following config variables will be provided to your application to connect:
REDIS_URLthe credentials for connecting to the cluster
REDIS_PREFIXthe key prefix accessible to the app