Description of problem: Pacemaker needs the ability to manage remote-nodes with dynamic ip addresses. For example, docker containers are assigned a random IP every time they start. For a docker container to become a remote-node, pacemaker needs to be made aware of what the IP address is for the container after the container starts. Currently there is no mechanism to allow this. To resolve this, the resource-agent associated with the remote-node container must have the ability to update Pacemaker with the container's IP during the agent's 'start' operation. This IP should be communicated with pacemaker via a transient attribute. From there pacemaker will use the address provided to it by this transient attribute to connect to the container's pacemaker_remote instance rather than a statically allocated address in the resource's configuration entry.
This option feature is no longer necessary. The use case this feature was meant to solve has already been solved by another means. It is possible to port forward pacemaker remote within a docker container to the host, which completely removes the need for pacemaker-remote to need to process dynamic IPs.