The option `services.prometheus.environmentFile` has been removed since it was causing [issues](https://github.com/NixOS/nixpkgs/issues/126083) and Prometheus now has native support for secret files.
The new option `services.prometheus.enableReload` has been introduced
which, when enabled, causes the prometheus systemd service to reload
when its config file changes.
More specifically the following property holds: switching to a
configuration (`switch-to-configuration`) that changes the prometheus
configuration only finishes successully when prometheus has finished
loading the new configuration.
`enableReload` is `false` by default in which case the old semantics
of restarting the prometheus systemd service are in effect.
For the same reason Alertmanager supports environmentFile to pass
secrets along, it is useful to support the same for Prometheus'
configuration to store bearer tokens outside the Nix store.
The format of the listenAddress option was recently changed to separate
the address and the port parts. There is now a legacy check that
tells users to update to the new format. This legacy check produces
a false positive on IPv6 addresses, since they contain colons.
Fix the regex to make it not match colons within IPv6 addresses.
Accessing the configured port of a service is quite useful, for example
when configuring virtual hosts for a service. The prometheus module did
not expose the configured por separately, making it unnecessarily
cumbersome to consume.
This is a breaking change only if you were setting `listenAddress` to
a non-standard value. If you were, you should now set `listenAddress`
and `port` separately.
A centralized list for these renames is not good because:
- It breaks disabledModules for modules that have a rename defined
- Adding/removing renames for a module means having to find them in the
central file
- Merge conflicts due to multiple people editing the central file
Prometheus2 does no longer support the command-line flag to specify
an alertmanager. Instead it now supports both service discovery and
configuration of alertmanagers in the alerting config section.
Simply mapping the previous option to an entry in the new alertmanagers
section is not enough to allow for complete configurations of an
alertmanager.
Therefore the option alertmanagerURL is no longer used and instead
a full alertmanager configuration is expected.
This makes sure that when a user hasn't set a Prometheus option it
won't show up in the prometheus.yml configuration file. This results
in smaller and easier to understand configuration files.
We previously filtered out the `_module` attribute in a NixOS
configuration by filtering it using the option's `apply` function.
This meant that every option that had a submodule type needed to have
this apply function. Adding this function is easy to forget thus this
mechanism is error prone.
We now recursively filter out the `_module` attributes at the place we
construct the Prometheus configuration file. Since we now do the filtering
centrally we don't have to do it per option making it less prone to errors.
This results in a smaller prometheus.yml config file.
It also allows us to use the same options for both prometheus-1 and
prometheus-2 since the new options for prometheus-2 default to null
and will be filtered out if they are not set.
