The Salt Mine

The Salt Mine is used to collect arbitrary data from Minions and store it on the Master. This data is then made available to all Minions via the salt.modules.mine module.

Mine data is gathered on the Minion and sent back to the Master where only the most recent data is maintained (if long term data is required use returners or the external job cache).

Mine vs Grains

Mine data is designed to be much more up-to-date than grain data. Grains are refreshed on a very limited basis and are largely static data. Mines are designed to replace slow peer publishing calls when Minions need data from other Minions. Rather than having a Minion reach out to all the other Minions for a piece of data, the Salt Mine, running on the Master, can collect it from all the Minions every Mine Interval, resulting in almost fresh data at any given time, with much less overhead.

Mine Functions

To enable the Salt Mine the mine_functions option needs to be applied to a Minion. This option can be applied via the Minion's configuration file, or the Minion's Pillar. The mine_functions option dictates what functions are being executed and allows for arguments to be passed in. The list of functions are available in the salt.module. If no arguments are passed, an empty list must be added like in the function in the example below:

mine_functions: []
    interface: eth0
    cidr: ''

In the example above has additional filters to help narrow down the results. In the above example IP addresses are only returned if they are on a eth0 interface and in the IP range.

Mine Functions Aliases

Function aliases can be used to provide friendly names, usage intentions or to allow multiple calls of the same function with different arguments. There is a different syntax for passing positional and key-value arguments. Mixing positional and key-value arguments is not supported.

New in version 2014.7.0.

  network.ip_addrs: [eth0]
  networkplus.internal_ip_addrs: []
    mine_function: network.ip_addrs
    - mine_function: grains.get
    - ip_interfaces

Mine Interval

The Salt Mine functions are executed when the Minion starts and at a given interval by the scheduler. The default interval is every 60 minutes and can be adjusted for the Minion via the mine_interval option:

mine_interval: 60

Mine in Salt-SSH

As of the 2015.5.0 release of salt, salt-ssh supports mine.get.

Because the Minions cannot provide their own mine_functions configuration, we retrieve the args for specified mine functions in one of three places, searched in the following order:

  1. Roster data
  2. Pillar
  3. Master config

The mine_functions are formatted exactly the same as in normal salt, just stored in a different location. Here is an example of a flat roster containing mine_functions:

  user: root
  mine_functions: ['echo "hello!"']
      interface: eth0


Because of the differences in the architecture of salt-ssh, mine.get calls are somewhat inefficient. Salt must make a new salt-ssh call to each of the Minions in question to retrieve the requested data, much like a publish call. However, unlike publish, it must run the requested function as a wrapper function, so we can retrieve the function args from the pillar of the Minion in question. This results in a non-trivial delay in retrieving the requested data.

Minions Targeting with Mine

The mine.get function supports various methods of Minions targeting to fetch Mine data from particular hosts, such as glob or regular expression matching on Minion id (name), grains, pillars and compound matches. See the salt.modules.mine module documentation for the reference.


Pillar data needs to be cached on Master for pillar targeting to work with Mine. Read the note in relevant section.


One way to use data from Salt Mine is in a State. The values can be retrieved via Jinja and used in the SLS file. The following example is a partial HAProxy configuration file and pulls IP addresses from all Minions with the "web" grain to add them to the pool of load balanced servers.


    - web


  network.ip_addrs: [eth0]

Then trigger the minions to refresh their pillar data by running:

salt '*' saltutil.refresh_pillar

Verify that the results are showing up in the pillar on the minions by executing the following and checking for network.ip_addrs in the output:

salt '*' pillar.items

Which should show that the function is present on the minion, but not include the output:
            - eth0

Mine data is typically only updated on the master every 60 minutes, this can be modified by setting:


mine_interval: 5

To force the mine data to update immediately run:

salt '*' mine.update

Setup the salt.states.file.managed state in /srv/salt/haproxy.sls:

    - name: /etc/haproxy/config
    - source: salt://haproxy_config
    - template: jinja

Create the Jinja template in /srv/salt/haproxy_config:

<...file contents snipped...>

{% for server, addrs in salt['mine.get']('roles:web', 'network.ip_addrs', tgt_type='grain') | dictsort() %}
server {{ server }} {{ addrs[0] }}:80 check
{% endfor %}

<...file contents snipped...>

In the above example, server will be expanded to the minion_id.


The expr_form argument will be renamed to tgt_type in the 2017.7.0 release of Salt.