The new system is slightly less flexible, but the code and lua
definitions is now a lot simpler and easier to understand.
In fact the old lua definition was not actually correct.
It is likely that existing configs require not/minimal tweaks to work
again.
It now has to be called 'setup', this makes it possible to just
include the table as a whole in devices and it will automatically call
the correct function.
Instead the client is now created on the rust side based on the config.
Devices that require the mqtt client will now instead need to be
constructor using a function. This function receives the mqtt client.
Due to changes made in mlua the new scheduler is much simpler. It also
had no real business being part of the device manager, so it has now been
moved to be part of the returned config.
The automation:mqtt module now gets loaded in a similar way as the
automation:devices and automation:utils modules.
This leads to a breaking change where instantiating a new mqtt client
the device manager needs to be explicitly passed in.
Instead of having to call all the module registration functions in one
place it is possible for each module to register itself in a global registry.
During startup all the all the modules will be registered
automatically.
This does currently have one weakness, to need to ensure that the crate
is linked.
The environment variable `AUTOMATION_CONFIG` has been renamed to
`AUTOMATION__ENTRYPOINT` and can now also be set in `automation.toml` by
specifying:
```
automation = "<path>"
```
Directly accessing the environment variables in lua in no longer
possible. To pass in configuration or secrets you can now instead make
use of the `variables` and `secrets` modules.
To set values in these modules you can either specify them in
`automation.toml`:
```
[variables]
<name> = <value>
[secrets]
<name> = <value>
```
Note that these values will get converted to a string.
You can also specify the environment variables
`AUTOMATION__VARIABLES__<name>` and `AUTOMATION__SECRETS__<name>` to
set variables and secrets respectively. By adding the suffix `__FILE` to
the environment variable name the contents of a file can be loaded into
the variable or secret.
Note that variables and secrets are identical in functionality and the
name difference exists purely to make it clear that secret values are
meant to be kept secret.
The function `new_mqtt_client` was the last remaining entry in the
global `automation` table. The function was renamed to `new` and placed
in the new `mqtt` module. As `automation` is now empty, it has been
removed.
Previously the fulfillment config was set by setting
`automation.fulfillment`, this will no longer work in the future when
the global automation gets split into modules.
