salt/doc/topics/execution/remote_execution.rst

Running Commands on Salt Minions

Salt can be controlled by a command line client by the root user on the Salt master. The Salt command line client uses the Salt client API to communicate with the Salt master server. The Salt client is straightforward and simple to use.

Using the Salt client commands can be easily sent to the minions.

Each of these commands accepts an explicit --config option to point to either the master or minion configuration file. If this option is not provided and the default configuration file does not exist then Salt falls back to use the environment variables SALT_MASTER_CONFIG and SALT_MINION_CONFIG.

Configuration <configuring-salt>

Using the Salt Command

The Salt command needs a few components to send information to the Salt minions. The target minions need to be defined, the function to call and any arguments the function requires.

Defining the Target Minions

The first argument passed to salt, defines the target minions, the target minions are accessed via their hostname. The default target type is a bash glob:

salt '*foo.com' sys.doc

Salt can also define the target minions with regular expressions:

salt -E '.*' cmd.run 'ls -l | grep foo'

Or to explicitly list hosts, salt can take a list:

salt -L foo.bar.baz,quo.qux cmd.run 'ps aux | grep foo'

More Powerful Targets

See Targeting <targeting>.

Calling the Function

The function to call on the specified target is placed after the target specification.

0.9.8

Functions may also accept arguments, space-delimited:

salt '*' cmd.exec_code python 'import sys; print sys.version'

Optional, keyword arguments are also supported:

salt '*' pip.install salt timeout=5 upgrade=True

They are always in the form of kwarg=argument.

Arguments are formatted as YAML:

salt '*' cmd.run 'echo "Hello: $FIRST_NAME"' env='{FIRST_NAME: "Joe"}'

Note: dictionaries must have curly braces around them (like the env keyword argument above). This was changed in 0.15.1: in the above example, the first argument used to be parsed as the dictionary {'echo "Hello': '$FIRST_NAME"'}. This was generally not the expected behavior.

If you want to test what parameters are actually passed to a module, use the test.arg_repr command:

salt '*' test.arg_repr 'echo "Hello: $FIRST_NAME"' env='{FIRST_NAME: "Joe"}'

Finding available minion functions

The Salt functions are self documenting, all of the function documentation can be retried from the minions via the sys.doc function:

salt '*' sys.doc

Compound Command Execution

If a series of commands needs to be sent to a single target specification then the commands can be sent in a single publish. This can make gathering groups of information faster, and lowers the stress on the network for repeated commands.

Compound command execution works by sending a list of functions and arguments instead of sending a single function and argument. The functions are executed on the minion in the order they are defined on the command line, and then the data from all of the commands are returned in a dictionary. This means that the set of commands are called in a predictable way, and the returned data can be easily interpreted.

Executing compound commands if done by passing a comma delimited list of functions, followed by a comma delimited list of arguments:

salt '*' cmd.run,test.ping,test.echo 'cat /proc/cpuinfo',,foo

The trick to look out for here, is that if a function is being passed no arguments, then there needs to be a placeholder for the absent arguments. This is why in the above example, there are two commas right next to each other. test.ping takes no arguments, so we need to add another comma, otherwise Salt would attempt to pass "foo" to test.ping.

If you need to pass arguments that include commas, then make sure you add spaces around the commas that separate arguments. For example:

salt '*' cmd.run,test.ping,test.echo 'echo "1,2,3"' , , foo

You may change the arguments separator using the --args-separator option:

salt --args-separator=:: '*' some.fun,test.echo params with , comma :: foo

CLI Completion

Shell completion scripts for the Salt CLI are available in the pkg Salt source directory.