In case of mult-server deployments, this can be confusing as each VM
generates different certificate files by default, where all instances
must share the same certificate (or at least CA certificate + key).
The other issue is that the MQTT broker certificate must contain the
correct hostname, which can (most of the times) not automatically be
retrieved. Documentation to generate these certificates can be found
here:
https://www.chirpstack.io/docs/guides/mosquitto-tls-configuration.html
With the update to diesel 2.0.0-rc0, it is now possible to cross-compile
without emulation. Note that during each (cross)compile, we have to
install libpq-dev for the target platform, as only one version can be
installed at a time (e.g. libpq-dev:amd64 conflicts with libpq-dev:armhf).