Serf only using TCP

[atul avhad]

Hi Team, 
The current use case I am dealing with is having only a few processes(around 20 at max). And the container technology I am using allows only TCP communication(for some security reasons). 

Is there a way to use SERF only with TCP. If that is not possible with the existing setup, can someone point me to the code base wherein I can make changes to force this ?

I understood that Memberlist package is being used for gossip protocol but I could not understand the fallback mechanism when only TCP connection is established and UDP fails.

Some points I noticed were, Membership changes (join, leave etc) are still working with TCP and events are propagated as well only with the existing mechanism. 

But it constantly throws the warning message

[WARN] memberlist: Was able to reach xyz(host) via TCP but not UDP, network maybe misconfigured and not allowing bidirectional UDP.  I wish to understand how this will affect the existing SERF setup and will serf automatically used TCP instead of UDP.

Regards,

Atul Avhad.