Re: [PATCH 5/6] tests/boot_linux_console: add extract_from_rpm method

[Liam Merwick <liam.merwick@oracle.com>]

On 31/01/2020 15:02, Liam Merwick wrote:

[... deleted ...]

>>
>>>>>
>>>>> +        :returns: path of the extracted file
>>>>> +        """
>>>>> +        cwd = os.getcwd()
>>>>> +        os.chdir(self.workdir)
>>>>> +        process.run("rpm2cpio %s | cpio -id %s" % (rpm, path), 
>>>>> shell=True)
>>>>> +        os.chdir(cwd)
>>>>> +        return self.workdir + '/' + path
>>>>                                    ^
>>>>      Is the extra slash needed? (just because the extract_from_deb()
>>>>      doesn't put it)
>>>>
>>>
>>>
>>> Yes, I needed to put it in there because the 'path' passed in for
>>> processing by cpio is a relative patch unlike the deb arg so it
>>> couldn't be just appended to 'self.workdir' which doesn't end in a '/'.
>>
>>
>> It is a good practice use the `os.path` module methods when dealing 
>> with filesystem paths. So that can be replaced with:
>>
>>  >>> os.path.normpath(os.path.join('/path/to/workdir', './file/in/rpm'))
>> '/path/to/workdir/file/in/rpm'
>>
> 
> 
> Will do.  I'll add a patch to fix extract_from_deb() too.

Using the exact same code didn't work with extract_from_deb() because 
the callers set 'path' to an absolute path (so os.path.join() drops the 
self.workdir part).  I'll include a patch with the following change and 
it can be dropped if people think using os.path.relpath() is too much of 
a hack.

--- a/tests/acceptance/boot_linux_console.py
+++ b/tests/acceptance/boot_linux_console.py
@@ -49,7 +49,12 @@ class BootLinuxConsole(Test):
          process.run("ar x %s %s" % (deb, file_path))
          archive.extract(file_path, self.workdir)
          os.chdir(cwd)
-        return self.workdir + path
+        # Return complete path to extracted file.  We need to use
+        # os.path.relpath() because callers specify 'path' with a leading
+        # slash which causes os.path.join() to interpret it as an absolute
+        # path and to drop self.workdir part.
+        return os.path.normpath(os.path.join(self.workdir,
+                                             os.path.relpath(path, '/')))

      def extract_from_rpm(self, rpm, path):
          """

Regards,
Liam