Currently the plugins pkg allows a single handler. This assumption breaks down if there are mutiple listeners to a plugin of a certain Manifest such as NetworkDriver or IpamDriver when swarm-mode is enabled. Signed-off-by: Madhu Venugopal <madhu@docker.com> Upstream-commit: 5e9c78aeaf1d88000921190b88a1d91d6261208c Component: engine