Messaging between Erlang nodes in Docker containers
Ping between nodes
Start Erlang docker container with host name host_a.
docker run -it --rm --name host_a -h host_a erlang bash
Start Erlang docker container with host name host_b and link to container host_a.
docker run -it --rm --name host_b -h host_b --link host_a erlang bash
On host_a start Erlang shell with short name node_a and magick cookie.
root@host_a:/# erl -sname node_a -setcookie cookie
On host_b start Erlang shell with short name node_b and same magick cookie.
root@host_b:/# erl -sname node_b -setcookie cookie
From node_b@host_b ping node_a@host_a.
(node_b@host_b)> net_adm:ping('node_a@host_a').
pong
Now from node_a@host_a is visible node_b@host_b and vice versa.
(node_a@host_a)> nodes().
[node_b@host_b]
(node_b@host_b)> nodes().
[node_a@host_a]
On node_a@host_a register shell process as receiver
(node_a@host_a)> register(receiver, self()).
true
and the same on node_b@host_b.
(node_b@host_b)> register(receiver, self()).
true
Now we can send message to process on another node
(node_a@host_a)> {receiver, 'node_b@host_b'} ! msg_from_a.
msg_from_a
and them receive message.
(node_b@host_b)> flush().
Shell got msg_from_a
ok
And so fort back.
(node_b@host_b)> {receiver, 'node_a@host_a'} ! msg_from_b.
msg_from_b
(node_a@host_a)> flush().
Shell got msg_from_b
ok