epmdlib

This is a embedded epmd library based on Erlang (and Elixir) distribution without epmd

Usage

Add epmdlib as a dependency in rebar.confg
```
{deps, [
     {epmdlib, "1.0.0"}
 ]}.
```

Add the following lines to vm.args file:

-proto_dist epmdlib_common
-start_epmd false
-epmd_module epmdlib_epmd_client
-epmdlib_dist_transport tcp

For Ipv6

-epmdlib_dist_transport tcp6

If -epmdlib_dist_transport argument is not specified, then epmdlib defaults to using tcp for the distribution protocol’s transport layer.

To setup distribution over TLS, add -ssl_dist_optfile "/path/to/dist.conf" to vm.args file. Also change -epmdlib_dist_transport option to tls or tls6. Then add the following information to /path/to/dist.conf file

[{server,
  [{certfile, "/path/to/certfile"},
   {keyfile, "/path/to/keyfile"},
   {cacertfile, "/path/to/cacertfile"},
   {verify, verify_peer},
   {fail_if_no_peer_cert, true},
   {secure_renegotiate, false}]},

 {client,
   [{certfile, "/path/to/certfile"},
   {keyfile, "/path/to/keyfile"},
   {cacertfile, "/path/to/cacertfile"},
   {verify, verify_peer},
   {secure_renegotiate, false}]}].

NOTE

When deploying an OTP application that uses epmdlib (for the first time), please make sure to kill any existing epmd process started by the previours version of the OTP application.
By default the library uses 4469 as the base port. If that port is not availabe, configure a different base port in your application’s sys.config.
```
[
{kernel, [
  {inet_dist_base_port, PORT} %% an available port
]}
].
```

Testing

Start two nodes foo1, foo2 and have them connect to each other.

erl -pa _build/default/lib/epmdlib/ebin/ -proto_dist epmdlib_common -start_epmd false -epmd_module epmdlib_epmd_client -epmdlib_dist_protocol tcp -sname foo1@localhost

erl -pa _build/default/lib/epmdlib/ebin/ -proto_dist epmdlib_common -start_epmd false -epmd_module epmdlib_epmd_client -epmdlib_dist_protocol tcp -sname foo2@localhost

If it is working correctly,

Erlang/OTP 22 [erts-10.6.2] [source] [64-bit] [smp:2:2] [ds:2:2:10] [async-threads:1] [hipe]

Eshell V10.6.2  (abort with ^G)
(foo1@localhost)1> net_adm:ping('foo2@localhost').
pong
(foo1@localhost)2>

Contributing

Update the version in src/epmdlib.app.src
Make changes and test
Update Usage section in README.md to reflect the latest version of the library
Commit and push the changes
Publish the package