[erlang-bugs] Cannot bind epmd to an IPv4 address after building with -DEPMD6

[Michael Santos]

On Tue, Dec 16, 2014 at 09:04:30AM +0100, Dariusz Gadomski wrote:
> On Fri, Nov 14, 2014 at 11:01:22AM +0100, Dariusz Gadomski wrote:
> > Hello everyone,
> > 
> > There are users observing problems with binding to an IPv4 address with
> > erlang 16b3 version built with -DEPMD6 flag [1]. This flag has been added
> > as a response to another bug [2].
> > 
> > By looking at erts/epmd/src/epmd_int.h I see that the address definitions are
> > mutually exclusive - enabling IPv6 makes all addresses IPv6-only which may
> > result in problems with binding to a specific IPv4 address:
> > $ ERL_EPMD_ADDRESS="127.0.0.1" epmd
> > epmd: Fri Nov 14 11:00:47 2014: cannot parse IP address "127.0.0.1"
> > 
> > Can you please confirm this? Is it a known issue? Maybe there is a workaround?
> > 
> > [1] https://bugs.launchpad.net/ubuntu/+source/erlang/+bug/1374109
> > [2] https://bugs.launchpad.net/ubuntu/+source/rabbitmq-server/+bug/1312507
> 
> Hello again,
> 
> I have made an interesting observation. There is a change linked from
> [3] on github [4]. This change adds support for IPv6 node registration to
> epmd.
> 
> As a side effect it fixes the original issue I mentioned above. Is
> anyone aware if there are any plans of merging it to the main
> codebase?
> 
> [3] http://www.erlang.org/development/
> [4] https://github.com/msantos/otp/compare/erlang:maint...epmd-IPv6-node-reg

There were problems compiling on Windows that could be fixed by removing
support for older versions:

http://erlang.org/pipermail/erlang-patches/2013-February/003528.html

I'll rebase the patch and make a new pull request.