py renderer

Let’s indicate that a file should be parsed with the py renderer with #!py at the top.

In that case, the file is interpreted as a Python file. Salt looks for a run function, runs it, and treats the return value as the state.

When running, __grains__ and __pillar__ contain the grain and pillar data.

As an example, you can implement the same logic with a py renderer.

#!py

def run():

if __grains__['os'] == 'CentOS':

package_name = 'python-devel'

elif __grains__['os'] == 'Debian':

package_name = 'python-dev'

else:

raise ValueError("Unrecognized operating

system",

__grains__['os'])

return { package_name: dict(pkg='installed') }

Since the py renderer is not a combination of two unrelated parsers, mistakes are sometimes easier to diagnose.

You get the following if you reintroduce the bug from the first version.

#!py

def run():

if __grains__['os'] == 'CentOS':

package_name = 'python-devel'

elif __grains__['os'] == 'Debian':

package_name = 'python-dev'

return { package_name: dict(pkg='installed') }

In this case, the result is a NameError pinpointing the erroneous line and the missing name.

The trade-off is that reading it in YAML form is more straightforward if the configuration is big and mostly static.