User FAQ

Use of environment variables on the command line

As discussed in Docker's documentation, the container's command is not necessarily executed in a shell, in which case environment variables are not expanded in command-line arguments. In particular, non-default commands are specified via Kubernetes's API using the array form of Docker's Cmd argument, which causes the command to be execed directly. You can cause environment variables to be evaluated by simply making your command a shell, with your application's command line as its argument. For example:

{ "command": [ "sh", "-c", "redis-server /etc/redis/redis.conf --slaveof $SERVICE_HOST $REDIS_MASTER_SERVICE_PORT"] }

How do I change the size of my cluster?

Change NUM_MINIONS in the platform-specific config-default.sh file, such as GCE's.

Currently, NUM_MINIONS needs to be changed before turning up the cluster.

How do I pull images from a private registry?

• For GKE and version 0.4, see the answer on stackoverflow
• For more recent versions of Kubernetes, create the registry service with a PortalIP address of your choice within the portal IP range, and use that IP address for the registry name