Executing a Salt state run can potentially change many aspects of a system and it may be desirable to first see what a state run is going to change before applying the run.
Salt has a test interface to report on exactly what will be changed, this interface can be invoked on any of the major state run functions:
# salt \* state.highstate test=True
# salt \* state.sls test=True
# salt \* state.single test=True
The test run is mandated by adding the test=True option to the states. The return information will show states that will be applied in yellow and the result is reported as None.
If the value test is set to True in the minion configuration file then states will default to being executed in test mode. If this value is set then states can still be run by calling test=False:
# salt \* state.highstate test=False
# salt \* state.sls test=False
# salt \* state.single test=False