These packages will be placed into an environment using
`backendsToPackages`. This function explicitly maps backends to
`pkgs.nodePackages.${type}` unless it's a builtin. This ensures that only
valid backends that work on NixOS are used (if not, the build already
breaks at evaluation time).
The log will be redirected to `stdout` to be able to watch the entire
output using `journalctl`.
Configuration parameters for the backends need to be set using
`services.statsd.extraConfig` as each backend has its own options and
all of them shouldn't be validated and checked explicitly and manually.
* package statsd node packages separatly since they actually require
nodejs-0.10 or nodejs-0.12 to work (which is ... well old)
* remove statsd packages and its backends from "global" node-packages.json.
i did not rebuild it since for some reason npm2nix command fails. next time
somebody will rerun npm2nix statsd packages are going to be removed.
* statsd service: backends are now provided as strings and not anymore as
packages.
graphitePort must point to the port that carbon-cache listens on, not
the graphite webUI port.
With this change I finally got data from statsd to graphite.
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
