This changes the clean_session default to false, as only in case of a
persistent session, qos > 0 would be effective. If the client_id is not
set, then ChirpStack will generate a random client_id, which stays the
same during the lifetime of the chirpstack process.
This also implements a subscribe loop, as the client re-connect feature
does not re-subscribe. Even in case of a persistent session there is no
guarantee that the subscription is recovered, as it might have been a
MQTT broker restart. In case the broker stores the sessions in-memory,
the client would re-connect, but without subscriptions.
The (re)subscribe logic is placed outside the on-connected callback, as
the callback function must not block, thus can not wait for the
subscribe result. No the (re)subscribe happens async from the
on-connected.
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).
Diesel 1.4.x makes it impossible to properly cross-compile when using
PostgreSQL and thus having a dependency on libpq. On compile and I
believe when using the diesel_migrations crate, there is a dependency on
both the host and target libpq. Unfortunately, only one can be installed
at a time, because of conflicts. See also:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=995768
Until now the cross-compile solution is based on docker buildx, which
uses qemu to emulate the different targets. This works, but is very,
very slow.
Diesel 2.0.0-rc.0 no longer depends on both the host and target libpq on
compile and makes it possible to implement proper cross-compiling (using
the rust --target flag in combination with the cross-compile
toolchains).
Adding this was probably not a good idea. For a number of reasons:
Persisted messages do not expire, so the database of messages will grow
over time, even when devices are removed.
Other integrations have nothing similar.
Decoded uplink events will probably data that could be seen as a certain
state (e.g. parking spot occupied or not), but are published as events.
