techhat / octosalt

A collection of Salt modules for OctoPrint

OctoSalt: OctoPrint Salt Modules

This is a collection of Salt modules for the OctoPrint 3D printing server. It allows an OctoPrint installation to function as a Salt minion, by way of Salt's proxy minion setup, using OctoPrint's built-in API.

Introduction

OctoSalt uses a proxy minion module, configured via pillar and designed to run from another minion which has access to the OctoPrint server.

For those not familiar with the concepts, here's a quick rundown.

Salt is a remote automation platform popular in data centers whose size ranges from just a handful of servers to tens of thousands. Its use is not limited to data centers, however. Its very nature makes it a perfect tool for the maker community, particularly on small Linux-based devices such as the Raspberry Pi.

A Salt master is the server which controls Salt minions.

A Salt minion is a device, usually a server running a full-blown OS such as Linux or Windows, which is managed by Salt. These devices are typically able to run the salt-minion service, which runs in Python.

In the event that a device is unable to run Python or otherwise run the salt-minion service, a proxy minion may be configured on either the master or one of the minions, to provide an interface which makes the device behave like any other minion.

The Salt pillar subsystem allows for minions to be configured from the Salt master instead of directly on the minion. Because a proxy minion is unable to store its own configuration, the pillar subsystem is usually used to configure it.

Installation

The files for this package must be installed on the minion which will host the proxy minion. The salt/ directory in this package may be placed directly in the /srv/ directory on that minion. This will create a directory tree that looks like:

/srv/
+-- salt/
    +-- _beacons/
    +-- _modules/
    +-- _proxy/
    +-- _states/

Configuration

The following assumes some familiarity with Salt. A more in-depth discussion of Salt itself can be found in the Getting Started guide.

First, configure /srv/pillar/top.sls on the Salt master:

base:
  octominion:
    - octosalt

In this example, octominion is the minion name by which Salt will refer to the printer. It is _not_ the name of the minion which will actually host the proxy module and perform the connection.

The octosalt line refers to /srv/pillar/octosalt.sls on the Salt master. Create that file with the following content:

proxy:
  proxytype: octoprint
  url: http://192.168.11.38

In this file, the only value that needs changing is the URL, which points to the OctoPrint server.

Unless the hostname for your Salt master is salt, you will also need to update the /etc/salt/proxy file on the minion which is hosting the proxy minion.

master: salt.mydomain.com

Finally, to start the proxy minion, create /srv/salt/octosalt.sls on the Salt master with the following content:

octosalt-configure:
  salt_proxy.configure_proxy:
    - proxyname: octominion
    - start: True

In this example, octominion refers to the minion name by which Salt will refer to the OctoPrint server, and not the minion which will host the proxy.

In order to start the proxy minion on the host minion, issue the following command from the Salt master:

# salt octopi state.sls octosalt

In this example, octopi refers to the minion which will host the proxy.

Then accept the key for the new proxy minion:

# salt-key -ya octominion