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.
This makes it possible to use the config examples with Docker Compose
(where every service has its own hostname) and to use it for packaging
(where by default the services are running under localhost).
This includes:
* Changing the modulation parameters to its own type.
* Changing the timing parameters to its own type.
* Change the gateway_id to string. As the json encoding for bytes fields
is base64, this was confusing some users.
* Change the uplink / downlink id to uint32 from uuid. A string
representation of the UUID field (for the same reason as the gateway
id) would consome quite some additional bytes. An uint32 provides
sufficient uniqueness for the purpose of uplink / downlink.
