Install custom CA certificate in Traefik

[DavidePrincipi]

In experimental environments, it is useful to point Traefik to a custom ACME server. We just need to add its certificate as a custom CA into Traefik's container.

This is an advanced use case, and shouldn't need an UI.

https://community.nethserver.org/t/custom-acme-server-tls-error-to-server/24682

Thanks to TBaile and mikart143

[DavidePrincipi]

In testing:

• core 3.6.0-dev.1
• traefik 3.0.0-testing.2

Test case

Upload the custom certificate via scp to custom_certificates/root-homelab.crt (check ownership and permissions).

Add a custom env-file to Podman run options, to include a custom environment file:

runagent -m traefik1 python3 -c 'import agent ; agent.set_env("PODMAN_RUN_OPTS", "--env-file=custom.env")'

Edit custom.env contents to customize LEGO as wanted. For example

LEGO_CA_CERTIFICATES=/etc/traefik/custom_certificates/root-homelab.crt

See https://community.nethserver.org/t/custom-acme-server-tls-error-to-server/24682/6?u=davidep