Mumble not working with MASH - SSL Certificate Error

[SunnyNixOS]

Configuring Mumble with MASH seems to have errors automatically generating the SSL certificate. I am currently running Jellyfin, Vikunja, and Audiobookshelf with no issues. Mumble is the only service causing this. I have confirmed I already correctly set up the DNS records as well.

If any context helps, I am also configuring the MASH playbook alongside the MDAD playbook, where the MDAD playbook is the primary controller of the Traefik instance.

journalctl -fu mash-mumble.service:
Feb 22 09:02:49 debian-server mash-mumble[4049216]: Setting config "sslCert" to: '/certificate.crt' 
Feb 22 09:02:49 debian-server mash-mumble[4049216]: Setting config "obfuscate" to: 'false' 
Feb 22 09:02:49 debian-server mash-mumble[4049216]: Setting config "sslKey" to: '/privatekey.key' 
Feb 22 09:02:49 debian-server mash-mumble[4049216]: Setting config "ice" to: '"tcp -h 127.0.0.1 -p 6502"' 
Feb 22 09:02:49 debian-server mash-mumble[4049216]: <X>2026-02-22 17:02:49.087 SSL: OpenSSL version is 'OpenSSL 3.0.13 30 Jan 2024' 
Feb 22 09:02:49 debian-server mash-mumble[4049216]: <W>2026-02-22 17:02:49.088 Initializing settings from /data/mumble_server_config.ini (basepath /data) 
Feb 22 09:02:49 debian-server mash-mumble[4049216]: <C>2026-02-22 17:02:49.088 MetaParams: Failed to read /certificate.crt 
Feb 22 09:02:49 debian-server mash-mumble[4049216]: <F>2026-02-22 17:02:49.088 MetaParams: Failed to load SSL settings. See previous errors. 
Feb 22 09:02:50 debian-server systemd[1]: mash-mumble.service: Main process exited, code=exited, status=1/FAILURE Feb 22 09:02:50 debian-server systemd[1]: mash-mumble.service: Failed with result 'exit-code'.

My current vars.yml:

# -------- Mumble -------- (having errors with ssl certs)
mumble_enabled: true
mumble_hostname: mumble.example.com
mumble_database_type: postgres
mumble_environment_variables_mumble_superuser_password: SUPERUSER_PASSWORD
mumble_environment_variables_mumble_verbose: true

I have also tried obtaining my own SSL certificates and using them instead to no avail.

[luixxiul]

Did you enable traefik-certs-dumper mentioned in the section for dependencies?

Traefik on the side of MDAD is not configured to automatically retrieve the certificate for Mumble, so you probably need to let MDAD's Traefik retrieve it.

If you got the certificate, mount it onto a volume and use mumble_environment_variables_mumble_config_sslcert and
mumble_environment_variables_mumble_config_sslkey instructed here. mumble_container_additional_volumes_auto inside group_vars_mash_servers might give you a hint about it.

Traefik on the MASH is configured to retrieve the certificate, as I confirmed just now.

[SunnyNixOS]

I did try this with both traefik-certs-dumper enabled by MDAD, and the one enabled by MASH.

I have also tried manually specifying SSL certificates with the following:

mumble_environment_variables_mumble_config_sslcert = 
mumble_environment_variables_mumble_config_sslkey =

I also configured additional volume in the same way you would with a service such as Jellyfin. All paths I have tried lead me to the same error as described above.

I will continue to do further testing when I am available, and I will make sure to inspect mumble_container_additional_volumes_auto as a potential solution. I appreciate your quick response.