Command.run() currently has a bit of a confusing behavior: if raise_on_error is
False and the executable is not found, then a weird CommandT is returned (return
code is -1 and stdout+stderr is None). This makes it possible to hanlde command
not found errors separately, but it makes that needlessly verbose. So instead,
let's just return None in *this* special case.
That in turn uncovered, that in most cases when we set `raise_on_error=True`, we
actually want an error if the command is not present but no error if the command
fails to execute (e.g. because it returns -1 if you run `$cmd --version`). Hence we
introduce the flag `raise_on_command_not_found`, which causes an exception to
be raised if the command is not found. This makes it independent of the
`raise_on_error` flag.
Additionally, we add a small optimization: if command starts with /, then we
assume it's a full path and we omit the call to which (and just check whether it
exists).
Co-authored-by: Marcus Schäfer <marcus.schaefer@gmail.com>
This commit prevents the use of a default stdout and stderr in case
return code reports errors and it is not raising an exception.
If we are not raising an exception there is no specific need to
artificially append some stdout and stderr default message, we just
behave as if there was no error.
The Command class creates namedtuple to store the result
of the call. That tuple is created inside of the Command
namespace. If called inside of a __del__ destructor which
is often the case in kiwi classes I recently observed an
exception from python saying:
File "/usr/lib64/python3.6/collections/__init__.py", line 429, in namedtuple
File "<string>", line 1, in <module>
ModuleNotFoundError: import of builtins halted; None in sys.modules
I do not understand why this is a problem for python now
and only found the solution in making the command_type variable
a global namedtuple.
Python2 is announced to be unmaintained from Jan 2020.
KIWI supports Python 2.7 and it should not support any python version that
is not maintained upstream. This Fixes#1036
This commit adds a stderr_to_stdout option to Command.run method to
redirect stderr to stdout.
Additionally this commit also includes to the debug log the dracut
call output, including both, stderr and stdout.
Fixes#1114
@classmethod are used in Python to represent methods that can
query and update the class (cls parameter). Is expected to be
used for metaprograming, or advanced techniques that require the
access to the class itself, before we have an instance.
@staticmethod are used to associate a function to a class. It will
not be have access to the instance (self) not the class (cls). In
other programming languages are known as class methods.
This patch replace all the @classmethod with @staticmethod when
there is not need to access to the cls parameter, because the
intention is to be used as normal functions.
In case of a literal decoding failure it tries to decode
the result in utf-8. This is handy in python2 environments where
python and the host might be using different charset configurations.
In python3 this issue seams to be solved.
Fixes#829 and bsc#1110871
Command.run and Command.call now make use of Path.which in order
to test if the command is available or not. Also Path.which has
been extended in order to support custom environments and to be
able to test file permissions (read. write, execute)
This commit includes a validation in Command.run and Command.call
in order to verify the existance of the command before running it.
It case it is not found in the specified environment it raises a
KiwiCommandNotFound Exception.
In python2 bytes is string which is different from the bytes
type in python3. The bytes type from the builtins generalizes
this type to be bytes always. However the redefinition of the
bytes type is marked as Smell in landscape. Thus the code
should at least inform why this is done
Also log the stdout data from a failed command. So far we
expected error data on stderr but there are also commands
which print error messages on stdout. It should us at least
worth a debug message with this information
