# State Providers

Added in version 0.9.8.

Salt predetermines what modules should be mapped to what uses based on the properties of a system. These determinations are generally made for modules that provide things like package and service management.

Sometimes in states, it may be necessary to use an alternative module to provide the needed functionality. For instance, an very old Arch Linux system may not be running systemd, so instead of using the systemd service module, you can revert to the default service module:

    httpd:
      service.running:
        - enable: True
        - provider: service

In this instance, the basic `service` module (which manages sysvinit-based services) will replace the `systemd` module which is used by default on Arch Linux.

This change only affects this one state though. If it is necessary to make this override for most or every service, it is better to just override the provider in the minion config file, as described here.

Also, keep in mind that this only works for states with an identically-named virtual module (`pkg`, `service`, etc.).

## Arbitrary Module Redirects

The provider statement can also be used for more powerful means, instead of overwriting or extending the module used for the named service an arbitrary module can be used to provide certain functionality.

    emacs:
      pkg.installed:
        - provider:
          - cmd: customcmd

In this example, the state is being instructed to use a custom module to invoke commands.

Arbitrary module redirects can be used to dramatically change the behavior of a given state.