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.
As the configuration for the exporters and alertmanager is unchanged
between the two major versions this patch tries to minimize
duplication while at the same time as there's no upgrade path from 1.x
to 2.x, it allows running the two services in parallel. See also #56037
With `promtool` we can check the validity of a configuration before
deploying it. This avoids situations where you would end up with a
broken monitoring system without noticing it - since the monitoring
broke down. :-)
...by providing a default value of "no labels" (an empty attrset).
Without this change we get
$ nixos-rebuild test -I nixpkgs=.
building Nix...
building the system configuration...
error: The option `services.prometheus.scrapeConfigs.[definition 1-entry 1].static_configs.[definition 1-entry 1].labels' is used but not defined.
which is unneeded, because labels _are_ optional.
The structured options are incomplete compared to upstream and I think
it will be a maintenance burden to try to keep up. Instead, provide an
option for the raw config file contents (prometheus.yml).
