I have trouble starting a remote node with ct_slave/start/3 on a remote host which uses kerl. I guess this is because ct_slave doesn’t use an interactive shell. The remote host is a Debian 11 machine. Any suggestions?
Trouble starting a remote node with ct_slave/start/3 on a remote host which uses kerl
kerl is about building the Erlang/OTP libraries and runtime environment, and would be unrelated to how you interact with it.
I guess a first question is can you make regular Erlang nodes talk to each other across these hosts and is it only failing with
ct_slave, or is it failing in general?
I do use ct_slave on a regular basis without a problem. Actually, ct_slave works fine from the host that has the kerl built Erlang instance. When using an interactive shell (ssh),
.profile is executed which activates an Erlang instance
if [ -d "$HOME/kerl" ] ; then . "$HOME/kerl/126.96.36.199/activate" fi
NB: I know, that’s an old version…
I’m just saying, kerl is about building Erlang and has no impact on the networking stack in general. This is like going “it was built with makefiles, why isn’t it connecting?”. I think you’re looking at the wrong thing.
I am asking whether with computer A and computer B where you are trying to use
ct_slave, you can get a regular Erlang shell, without
ct_slave, to connect. So the question here is whether the issue is around
ct_slave usage, or more broadly, the network between the two hosts and the ability for distributed Erlang to work.
I don’t think how you built Erlang is relevant unless one node is on a much newer version than the other.
There is no problem starting an interactive Erlang shell on the remote system because the
.profile (or bashrc or something similar) file is executed. But with ct_slave, the file
.profile is not executed because it is not an interactive shell. I have not yet found any other way in sshd that allows me to execute
kerl activate when connecting via ct_slave. So it is mainly an sshd problem.
Fixed it: I did overlook the first few lines in
.bashrc which exited the script when not interactive. A quick fix was to add the next few lines in
case $- in *i*) ;; *) if [ -d "$HOME/kerl" ] ; then . "$HOME/kerl/188.8.131.52/activate" fi return;; esac