[PATCH v3 28/32] tests/functional: replace 'run_cmd' with subprocess helpers

[Daniel P . Berrangé]

The 'run_cmd' helper is re-implementing a convenient helper that
already exists in the form of the 'run' and 'check_call' methods
provided by 'subprocess'.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 tests/functional/qemu_test/archive.py    |  9 ++++---
 tests/functional/qemu_test/tesseract.py  | 10 ++++----
 tests/functional/qemu_test/testcase.py   | 31 +++++++++++++-----------
 tests/functional/qemu_test/tuxruntest.py |  8 +++---
 tests/functional/test_aarch64_virt.py    |  6 +++--
 tests/functional/test_ppc64_tuxrun.py    |  7 ++++--
 6 files changed, 41 insertions(+), 30 deletions(-)

diff --git a/tests/functional/qemu_test/archive.py 
b/tests/functional/qemu_test/archive.py
index c439d9413a..c803fdaf6d 100644
--- a/tests/functional/qemu_test/archive.py
+++ b/tests/functional/qemu_test/archive.py
@@ -14,7 +14,6 @@
 import zipfile
 
 from .asset import Asset
-from .cmd import run_cmd
 
 
 def tar_extract(archive, dest_dir, member=None):
@@ -52,9 +51,11 @@ def deb_extract(archive, dest_dir, member=None):
     cwd = os.getcwd()
     os.chdir(dest_dir)
     try:
-        (stdout, stderr, ret) = run_cmd(['ar', 't', archive])
-        file_path = stdout.split()[2]
-        run_cmd(['ar', 'x', archive, file_path])
+        proc = run(['ar', 't', archive],
+                   check=True, capture_output=True, encoding='utf8')
+        file_path = proc.stdout.split()[2]
+        check_call(['ar', 'x', archive, file_path],
+                   stdout=DEVNULL, stderr=DEVNULL)
         tar_extract(file_path, dest_dir, member)
     finally:
         os.chdir(cwd)
diff --git a/tests/functional/qemu_test/tesseract.py 
b/tests/functional/qemu_test/tesseract.py
index 1b7818090a..ede6c6501e 100644
--- a/tests/functional/qemu_test/tesseract.py
+++ b/tests/functional/qemu_test/tesseract.py
@@ -6,18 +6,18 @@
 # later. See the COPYING file in the top-level directory.
 
 import logging
+from subprocess import run
 
-from . import run_cmd
 
 def tesseract_ocr(image_path, tesseract_args=''):
     console_logger = logging.getLogger('console')
     console_logger.debug(image_path)
-    (stdout, stderr, ret) = run_cmd(['tesseract', image_path,
-                                     'stdout'])
-    if ret:
+    proc = run(['tesseract', image_path, 'stdout'],
+               capture_output=True, encoding='utf8')
+    if proc.returncode:
         return None
     lines = []
-    for line in stdout.split('\n'):
+    for line in proc.stdout.split('\n'):
         sline = line.strip()
         if len(sline):
             console_logger.debug(sline)
diff --git a/tests/functional/qemu_test/testcase.py 
b/tests/functional/qemu_test/testcase.py
index d0bb3141d5..aa6c9c0d64 100644
--- a/tests/functional/qemu_test/testcase.py
+++ b/tests/functional/qemu_test/testcase.py
@@ -16,7 +16,7 @@
 from pathlib import Path
 import pycotap
 import shutil
-import subprocess
+from subprocess import run
 import sys
 import tempfile
 import unittest
@@ -27,7 +27,6 @@
 
 from .archive import archive_extract
 from .asset import Asset
-from .cmd import run_cmd
 from .config import BUILD_DIR
 from .uncompress import uncompress
 
@@ -251,11 +250,11 @@ def add_ldpath(self, ldpath):
         self._ldpath.append(os.path.abspath(ldpath))
 
     def run_cmd(self, bin_path, args=[]):
-        return subprocess.run([self.qemu_bin]
-                              + ["-L %s" % ldpath for ldpath in self._ldpath]
-                              + [bin_path]
-                              + args,
-                              text=True, capture_output=True)
+        return run([self.qemu_bin]
+                   + ["-L %s" % ldpath for ldpath in self._ldpath]
+                   + [bin_path]
+                   + args,
+                   text=True, capture_output=True)
 
 class QemuSystemTest(QemuBaseTest):
     """Facilitates system emulation tests."""
@@ -282,7 +281,9 @@ def setUp(self):
     def set_machine(self, machinename):
         # TODO: We should use QMP to get the list of available machines
         if not self._machinehelp:
-            self._machinehelp = run_cmd([self.qemu_bin, '-M', 'help'])[0];
+            self._machinehelp = run(
+                [self.qemu_bin, '-M', 'help'],
+                capture_output=True, check=True, encoding='utf8').stdout
         if self._machinehelp.find(machinename) < 0:
             self.skipTest('no support for machine ' + machinename)
         self.machine = machinename
@@ -310,15 +311,17 @@ def require_accelerator(self, accelerator):
                           "available" % accelerator)
 
     def require_netdev(self, netdevname):
-        netdevhelp = run_cmd([self.qemu_bin,
-                             '-M', 'none', '-netdev', 'help'])[0];
-        if netdevhelp.find('\n' + netdevname + '\n') < 0:
+        help = run([self.qemu_bin,
+                    '-M', 'none', '-netdev', 'help'],
+                   capture_output=True, check=True, encoding='utf8').stdout;
+        if help.find('\n' + netdevname + '\n') < 0:
             self.skipTest('no support for " + netdevname + " networking')
 
     def require_device(self, devicename):
-        devhelp = run_cmd([self.qemu_bin,
-                           '-M', 'none', '-device', 'help'])[0];
-        if devhelp.find(devicename) < 0:
+        help = run([self.qemu_bin,
+                    '-M', 'none', '-device', 'help'],
+                   capture_output=True, check=True, encoding='utf8').stdout;
+        if help.find(devicename) < 0:
             self.skipTest('no support for device ' + devicename)
 
     def _new_vm(self, name, *args):
diff --git a/tests/functional/qemu_test/tuxruntest.py 
b/tests/functional/qemu_test/tuxruntest.py
index 0b1bb8f0ed..7227a83757 100644
--- a/tests/functional/qemu_test/tuxruntest.py
+++ b/tests/functional/qemu_test/tuxruntest.py
@@ -11,11 +11,12 @@
 
 import os
 import stat
+from subprocess import check_call, DEVNULL
 
 from qemu_test import QemuSystemTest
 from qemu_test import exec_command_and_wait_for_pattern
 from qemu_test import wait_for_console_pattern
-from qemu_test import which, run_cmd, get_qemu_img
+from qemu_test import which, get_qemu_img
 
 class TuxRunBaselineTest(QemuSystemTest):
 
@@ -76,8 +77,9 @@ def fetch_tuxrun_assets(self, kernel_asset, rootfs_asset, 
dtb_asset=None):
 
         disk_image = self.scratch_file("rootfs.ext4")
 
-        run_cmd(['zstd', "-f", "-d", disk_image_zst,
-                 "-o", disk_image])
+        check_call(['zstd', "-f", "-d", disk_image_zst,
+                    "-o", disk_image],
+                   stdout=DEVNULL, stderr=DEVNULL)
         # zstd copies source archive permissions for the output
         # file, so must make this writable for QEMU
         os.chmod(disk_image, stat.S_IRUSR | stat.S_IWUSR)
diff --git a/tests/functional/test_aarch64_virt.py 
b/tests/functional/test_aarch64_virt.py
index cc49f8963d..08576b0694 100755
--- a/tests/functional/test_aarch64_virt.py
+++ b/tests/functional/test_aarch64_virt.py
@@ -12,10 +12,11 @@
 
 import time
 import logging
+from subprocess import check_call, DEVNULL
 
 from qemu_test import QemuSystemTest, Asset
 from qemu_test import exec_command, wait_for_console_pattern
-from qemu_test import get_qemu_img, run_cmd
+from qemu_test import get_qemu_img
 
 
 class Aarch64VirtMachine(QemuSystemTest):
@@ -96,7 +97,8 @@ def common_aarch64_virt(self, machine):
         logger.info('creating scratch qcow2 image')
         image_path = self.scratch_file('scratch.qcow2')
         qemu_img = get_qemu_img(self)
-        run_cmd([qemu_img, 'create', '-f', 'qcow2', image_path, '8M'])
+        check_call([qemu_img, 'create', '-f', 'qcow2', image_path, '8M'],
+                   stdout=DEVNULL, stderr=DEVNULL)
 
         # Add the device
         self.vm.add_args('-blockdev',
diff --git a/tests/functional/test_ppc64_tuxrun.py 
b/tests/functional/test_ppc64_tuxrun.py
index 03b47e07f2..8a98d18ab3 100755
--- a/tests/functional/test_ppc64_tuxrun.py
+++ b/tests/functional/test_ppc64_tuxrun.py
@@ -11,9 +11,10 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+from subprocess import check_call, DEVNULL
 import tempfile
 
-from qemu_test import run_cmd, Asset
+from qemu_test import Asset
 from qemu_test.tuxruntest import TuxRunBaselineTest
 
 class TuxRunPPC64Test(TuxRunBaselineTest):
@@ -70,7 +71,9 @@ def ppc64_common_tuxrun(self, kernel_asset, rootfs_asset, 
prefix):
         # Create a temporary qcow2 and launch the test-case
         with tempfile.NamedTemporaryFile(prefix=prefix,
                                          suffix='.qcow2') as qcow2:
-            run_cmd([self.qemu_img, 'create', '-f', 'qcow2', qcow2.name, ' 
1G'])
+            check_call([self.qemu_img, 'create', '-f', 'qcow2',
+                        qcow2.name, ' 1G'],
+                       stdout=DEVNULL, stderr=DEVNULL)
 
             self.vm.add_args('-drive', 'file=' + qcow2.name +
                          ',format=qcow2,if=none,id='
-- 
2.46.0