[Bug]: VerneMQ 2.1.2 and plugins.vmq_passwd #2472
Description
Environment
- VerneMQ Version: 2.1.2
- OS: Docker
- Cluster size/standalone: standalone
Current Behavior
I'm doing the following in order to configure a setup where:
- my devices can connect through certificates
- I have root user access through username password for my backend
I'm creating a passwd.plain file in the Docker container, then the Docker startup script is something like this
#!/bin/sh
set -e
echo "🔐 VerneMQ startup: Preparing password file..."
# Always copy plain password file and hash it
# This ensures passwords are always hashed exactly once from the known plain source
echo "📋 Copying plain passwords from vmq.passwd.plain..."
cp /vernemq/etc/vmq.passwd.plain /vernemq/etc/vmq.passwd
echo "🔒 Hashing passwords using vmq-passwd -U..."
/vernemq/bin/vmq-passwd -U /vernemq/etc/vmq.passwd
echo "✓ Passwords hashed successfully"
echo "🚀 Starting VerneMQ..."
exec /usr/sbin/start_vernemqit seems to start the server, but then it keeps crashing with errors related to the password manager, and I'm not sure how to troubleshoot? eg
2026-01-27T16:09:19.045769+00:00 [error] <0.581.0> proc_lib:crash_report/4:950: crasher:
initial call: vmq_passwd_reloader:init/1, pid: <0.581.0>, registered_name: [], error:
{badarg,[{erlang,apply,[vmq_swc_plugin,cluster_events_add_handler,undefined],[{error_info,#
{module => erl_erts_errors}}]},{vmq_passwd_reloader,init,1,[{file,"/opt/vernemq/apps/vmq_pa
sswd/src/vmq_passwd_reloader.erl"},{line,70}]},{gen_server,init_it,2,[{file,"gen_server.erl
"},{line,2229}]},{gen_server,init_it,6,[{file,"gen_server.erl"},{line,2184}]},{proc_lib,ini
t_p_do_apply,3,[{file,"proc_lib.erl"},{line,329}]}]}, ancestors:
[vmq_passwd_sup,<0.579.0>], message_queue_len: 0, messages: [], links: [<0.580.0>],
dictionary: [], trap_exit: false, status: running, heap_size: 1598, stack_size: 29,
reductions: 499; neighbours:
2026-01-27T16:09:19.046425+00:00 [error] <0.580.0> supervisor:start_children/2:937:
Supervisor: {local,vmq_passwd_sup}. Context: start_error. Reason: {badarg,[{erlang,apply,[v
mq_swc_plugin,cluster_events_add_handler,undefined],[{error_info,#{module =>
erl_erts_errors}}]},{vmq_passwd_reloader,init,1,[{file,"/opt/vernemq/apps/vmq_passwd/src/vm
q_passwd_reloader.erl"},{line,70}]},{gen_server,init_it,2,[{file,"gen_server.erl"},{line,22
29}]},{gen_server,init_it,6,[{file,"gen_server.erl"},{line,2184}]},{proc_lib,init_p_do_appl
y,3,[{file,"proc_lib.erl"},{line,329}]}]}. Offender: id=vmq_passwd_reloader,pid=undefined.
2026-01-27T16:09:19.047601+00:00 [error] <0.578.0> proc_lib:crash_report/4:950: crasher:
initial call: application_master:init/3, pid: <0.578.0>, registered_name: [], exit:
{{{shutdown,{failed_to_start_child,vmq_passwd_reloader,{badarg,[{erlang,apply,[vmq_swc_plug
in,cluster_events_add_handler,undefined],[{error_info,#{module =>
erl_erts_errors}}]},{vmq_passwd_reloader,init,1,[{file,"/opt/vernemq/apps/vmq_passwd/src/vm
q_passwd_reloader.erl"},{line,70}]},{gen_server,init_it,2,[{file,"gen_server.erl"},{line,22
29}]},{gen_server,init_it,6,[{file,"gen_server.erl"},{line,2184}]},{proc_lib,init_p_do_appl
y,3,[{file,"proc_lib.erl"},{line,329}]}]}}},{vmq_passwd_app,start,[normal,[]]}},[{applicatiExpected behaviour
It should run with the password file
Configuration, logs, error output, etc.
Code of Conduct
- I agree to follow the VerneMQ's Code of Conduct