Since the Salt minion contains such extensive functionality it can be useful to run it standalone. A standalone minion can be used to do a number of things:
When running Salt in masterless mode, do not run the salt-minion daemon. Otherwise, it will attempt to connect to a master and fail. The salt-call command stands on its own and does not need the salt-minion daemon.
The salt-call command is used to run module functions locally on a minion
instead of executing them from the master. Normally the salt-call command
checks into the master to retrieve file server and pillar data, but when
running standalone salt-call needs to be instructed to not check the master for
this data. To instruct the minion to not look for a master when running
file_client configuration option needs to be set.
By default the
file_client is set to
remote so that the
minion knows that file server and pillar data are to be gathered from the
master. When setting the
file_client option to
minion is configured to not gather this data from the master.
Now the salt-call command will not look for a master and will assume that the local system has all of the file and pillar resources.
The state system can be easily run without a Salt master, with all needed files local to the minion. To do this the minion configuration file needs to be set up to know how to return file_roots information like the master. The file_roots setting defaults to /srv/salt for the base environment just like on the master:
file_roots: base: - /srv/salt
Now set up the Salt State Tree, top file, and SLS modules in the same way that
they would be set up on a master. Now, with the
option set to
local and an available state tree then calls to functions in
the state module will use the information in the file_roots on the minion
instead of checking in with the master.
Remember that when creating a state tree on a minion there are no syntax or path changes needed, SLS modules written to be used from a master do not need to be modified in any way to work with a minion.
This makes it easy to "script" deployments with Salt states without having to set up a master, and allows for these SLS modules to be easily moved into a Salt master as the deployment grows.
The declared state can now be executed with:
Or the salt-call command can be executed with the
--local flag, this makes
it unnecessary to change the configuration file:
salt-call state.highstate --local