This adds a helper method that modules can call to execute a command via
subproces. It takes two arguments: the command to run and
keyword options that control how the process is executed. Supported
options are: fail_on_rc_non_zero, close_fds, and executable.
fail_on_rc_non_zero will call fail_json if the command fails. If
args is a list, the command will be run with shell=False; otherwise, if
a string, it will be run with shell=True. Otherwise, run_command() returns
the returncode, stdout, and stderr.
For compatibility with older releases as well as avoiding things like
action: raw executable= show status
to communicate with devices that don't have sh.
Two problems here
* unchecked exception handling and erroneous assumption as to why
an exception might fire
* although the file module expands the path, when using file_args
the unexpanded path is passed.
Expected result: ~/path/to/file should work fine
Actual result: exception is because it doesn't find file with a message
about not being able to get the selinux context
Added two additional template variables
* template_fullpath - absolute path to the template
* template_run_date - date that the template was rendered
Documented these additional variables in the module documentation
Path might have to be expanded on some operations. It seems that path
containing '~' are not.
Using os.path.expanduser in appropriate places solves the problem, but
this might be required in many other places.
It seems that os.path.basename(__file__) can return a unicode
string. In this case syslog.openlog fails. Forcing the result
to a string causes the resulting error to go away.
Since we use 'raw' heavily on equipment where 'command' and 'shell' are not (yet) working (and python may need to be installed first using raw) these improvements are necessary in order to write more complex scripts (with return code handling and separated stdout/stderr).
This change includes the following changes:
- exec_command() now returns the return code of the command
- _low_level_exec_command() now returns a dict, including 'rc', 'stdout' and 'stderr'
- all users of the above interfaces have been improved to make use of the above changes
- all connection plugins have been modified to return rc and stderr
- fix the newline problem (stdout and stderr would have excess newlines)
In a future commit I intend to add assertions or error handling code to verify the return code in those places where it wasn't done. Since only the output was available, the return code was ignored, even though we expect them to be 0.
