tests: replace pycodestyle with black

Drop pycodestyle for code style checking in favor of black. Black is
much faster, stable PEP8 compliant code style checker offering also
automatic formatting. It aims to be very stable and produce smallest
diffs. It's used by many small and big projects.

Running checkstyle with black takes a few seconds with a terse output.
Thus, test-checkstyle-diff is no longer necessary.

Expand scope of checkstyle to all python files in the repo, replacing
test-checkstyle with checkstyle-python.

Also, fixstyle-python is now available for automatic style formatting.

Note: python virtualenv has been consolidated in test/Makefile,
test/requirements*.txt which will eventually be moved to a central
location.  This is required to simply the automated generation of
docker executor images in the CI.

Type: improvement
Change-Id: I022a326603485f58585e879ac0f697fceefbc9c8
Signed-off-by: Klement Sekera <klement.sekera@gmail.com>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

1 files changed, 188 insertions, 166 deletions

diff --git a/extras/vpp_config/vpp_config.py b/extras/vpp_config/vpp_config.py
index e863cde854e..74051300677 100755
--- a/extras/vpp_config/vpp_config.py
+++ b/extras/vpp_config/vpp_config.py
@@ -32,16 +32,16 @@ try:
 except NameError:
     pass
 
-VPP_DRYRUNDIR = '/vpp/vpp-config/dryrun'
-VPP_AUTO_CONFIGURATION_FILE = '/vpp/vpp-config/configs/auto-config.yaml'
-VPP_HUGE_PAGE_FILE = '/vpp/vpp-config/dryrun/sysctl.d/80-vpp.conf'
-VPP_STARTUP_FILE = '/vpp/vpp-config/dryrun/vpp/startup.conf'
-VPP_GRUB_FILE = '/vpp/vpp-config/dryrun/default/grub'
-VPP_REAL_HUGE_PAGE_FILE = '/etc/sysctl.d/80-vpp.conf'
-VPP_REAL_STARTUP_FILE = '/etc/vpp/startup.conf'
-VPP_REAL_GRUB_FILE = '/etc/default/grub'
+VPP_DRYRUNDIR = "/vpp/vpp-config/dryrun"
+VPP_AUTO_CONFIGURATION_FILE = "/vpp/vpp-config/configs/auto-config.yaml"
+VPP_HUGE_PAGE_FILE = "/vpp/vpp-config/dryrun/sysctl.d/80-vpp.conf"
+VPP_STARTUP_FILE = "/vpp/vpp-config/dryrun/vpp/startup.conf"
+VPP_GRUB_FILE = "/vpp/vpp-config/dryrun/default/grub"
+VPP_REAL_HUGE_PAGE_FILE = "/etc/sysctl.d/80-vpp.conf"
+VPP_REAL_STARTUP_FILE = "/etc/vpp/startup.conf"
+VPP_REAL_GRUB_FILE = "/etc/default/grub"
 
-rootdir = ''
+rootdir = ""
 
 
 def autoconfig_yn(question, default):
@@ -57,16 +57,16 @@ def autoconfig_yn(question, default):
     """
     input_valid = False
     default = default.lower()
-    answer = ''
+    answer = ""
     while not input_valid:
         answer = input(question)
         if len(answer) == 0:
             answer = default
-        if re.findall(r'[YyNn]', answer):
+        if re.findall(r"[YyNn]", answer):
             input_valid = True
             answer = answer[0].lower()
         else:
-            print ("Please answer Y, N or Return.")
+            print("Please answer Y, N or Return.")
 
     return answer
 
@@ -86,24 +86,21 @@ def autoconfig_cp(node, src, dst):
 
     # If the destination file exist, create a copy if one does not already
     # exist
-    ofile = dst + '.orig'
-    (ret, stdout, stderr) = VPPUtil.exec_command('ls {}'.format(dst))
+    ofile = dst + ".orig"
+    (ret, stdout, stderr) = VPPUtil.exec_command("ls {}".format(dst))
     if ret == 0:
-        cmd = 'cp {} {}'.format(dst, ofile)
+        cmd = "cp {} {}".format(dst, ofile)
         (ret, stdout, stderr) = VPPUtil.exec_command(cmd)
         if ret != 0:
-            raise RuntimeError('{} failed on node {} {} {}'.
-                               format(cmd,
-                                      node['host'],
-                                      stdout,
-                                      stderr))
+            raise RuntimeError(
+                "{} failed on node {} {} {}".format(cmd, node["host"], stdout, stderr)
+            )
 
     # Copy the source file
-    cmd = 'cp {} {}'.format(src, os.path.dirname(dst))
+    cmd = "cp {} {}".format(src, os.path.dirname(dst))
     (ret, stdout, stderr) = VPPUtil.exec_command(cmd)
     if ret != 0:
-        raise RuntimeError('{} failed on node {} {}'.
-                           format(cmd, node['host'], stderr))
+        raise RuntimeError("{} failed on node {} {}".format(cmd, node["host"], stderr))
 
 
 def autoconfig_diff(node, src, dst):
@@ -124,12 +121,10 @@ def autoconfig_diff(node, src, dst):
     # Diff the files and return the output
     cmd = "diff {} {}".format(src, dst)
     (ret, stdout, stderr) = VPPUtil.exec_command(cmd)
-    if stderr != '':
-        raise RuntimeError('{} failed on node {} {} {}'.
-                           format(cmd,
-                                  node['host'],
-                                  ret,
-                                  stderr))
+    if stderr != "":
+        raise RuntimeError(
+            "{} failed on node {} {} {}".format(cmd, node["host"], ret, stderr)
+        )
 
     return stdout
 
@@ -160,13 +155,15 @@ def autoconfig_hugepage_apply(node, ask_questions=True):
     """
 
     diffs = autoconfig_diff(node, VPP_REAL_HUGE_PAGE_FILE, rootdir + VPP_HUGE_PAGE_FILE)
-    if diffs != '':
-        print ("These are the changes we will apply to")
-        print ("the huge page file ({}).\n".format(VPP_REAL_HUGE_PAGE_FILE))
-        print (diffs)
+    if diffs != "":
+        print("These are the changes we will apply to")
+        print("the huge page file ({}).\n".format(VPP_REAL_HUGE_PAGE_FILE))
+        print(diffs)
         if ask_questions:
-            answer = autoconfig_yn("\nAre you sure you want to apply these changes [Y/n]? ", 'y')
-            if answer == 'n':
+            answer = autoconfig_yn(
+                "\nAre you sure you want to apply these changes [Y/n]? ", "y"
+            )
+            if answer == "n":
                 return -1
 
         # Copy and sysctl
@@ -174,10 +171,11 @@ def autoconfig_hugepage_apply(node, ask_questions=True):
         cmd = "sysctl -p {}".format(VPP_REAL_HUGE_PAGE_FILE)
         (ret, stdout, stderr) = VPPUtil.exec_command(cmd)
         if ret != 0:
-            raise RuntimeError('{} failed on node {} {} {}'.
-                               format(cmd, node['host'], stdout, stderr))
+            raise RuntimeError(
+                "{} failed on node {} {} {}".format(cmd, node["host"], stdout, stderr)
+            )
     else:
-        print ('\nThere are no changes to the huge page configuration.')
+        print("\nThere are no changes to the huge page configuration.")
 
     return 0
 
@@ -196,19 +194,21 @@ def autoconfig_vpp_apply(node, ask_questions=True):
     """
 
     diffs = autoconfig_diff(node, VPP_REAL_STARTUP_FILE, rootdir + VPP_STARTUP_FILE)
-    if diffs != '':
-        print ("These are the changes we will apply to")
-        print ("the VPP startup file ({}).\n".format(VPP_REAL_STARTUP_FILE))
-        print (diffs)
+    if diffs != "":
+        print("These are the changes we will apply to")
+        print("the VPP startup file ({}).\n".format(VPP_REAL_STARTUP_FILE))
+        print(diffs)
         if ask_questions:
-            answer = autoconfig_yn("\nAre you sure you want to apply these changes [Y/n]? ", 'y')
-            if answer == 'n':
+            answer = autoconfig_yn(
+                "\nAre you sure you want to apply these changes [Y/n]? ", "y"
+            )
+            if answer == "n":
                 return -1
 
         # Copy the VPP startup
         autoconfig_cp(node, rootdir + VPP_STARTUP_FILE, VPP_REAL_STARTUP_FILE)
     else:
-        print ('\nThere are no changes to VPP startup.')
+        print("\nThere are no changes to VPP startup.")
 
     return 0
 
@@ -226,49 +226,52 @@ def autoconfig_grub_apply(node, ask_questions=True):
 
     """
 
-    print ("\nThe configured grub cmdline looks like this:")
-    configured_cmdline = node['grub']['default_cmdline']
-    current_cmdline = node['grub']['current_cmdline']
-    print (configured_cmdline)
-    print ("\nThe current boot cmdline looks like this:")
-    print (current_cmdline)
+    print("\nThe configured grub cmdline looks like this:")
+    configured_cmdline = node["grub"]["default_cmdline"]
+    current_cmdline = node["grub"]["current_cmdline"]
+    print(configured_cmdline)
+    print("\nThe current boot cmdline looks like this:")
+    print(current_cmdline)
     if ask_questions:
         question = "\nDo you want to keep the current boot cmdline [Y/n]? "
-        answer = autoconfig_yn(question, 'y')
-        if answer == 'y':
+        answer = autoconfig_yn(question, "y")
+        if answer == "y":
             return
 
-    node['grub']['keep_cmdline'] = False
+    node["grub"]["keep_cmdline"] = False
 
     # Diff the file
     diffs = autoconfig_diff(node, VPP_REAL_GRUB_FILE, rootdir + VPP_GRUB_FILE)
-    if diffs != '':
-        print ("These are the changes we will apply to")
-        print ("the GRUB file ({}).\n".format(VPP_REAL_GRUB_FILE))
-        print (diffs)
+    if diffs != "":
+        print("These are the changes we will apply to")
+        print("the GRUB file ({}).\n".format(VPP_REAL_GRUB_FILE))
+        print(diffs)
         if ask_questions:
-            answer = autoconfig_yn("\nAre you sure you want to apply these changes [y/N]? ", 'n')
-            if answer == 'n':
+            answer = autoconfig_yn(
+                "\nAre you sure you want to apply these changes [y/N]? ", "n"
+            )
+            if answer == "n":
                 return -1
 
         # Copy and update grub
         autoconfig_cp(node, rootdir + VPP_GRUB_FILE, VPP_REAL_GRUB_FILE)
         distro = VPPUtil.get_linux_distro()
-        if distro[0] == 'Ubuntu':
+        if distro[0] == "Ubuntu":
             cmd = "update-grub"
         else:
             cmd = "grub2-mkconfig -o /boot/grub2/grub.cfg"
 
         (ret, stdout, stderr) = VPPUtil.exec_command(cmd)
         if ret != 0:
-            raise RuntimeError('{} failed on node {} {} {}'.
-                               format(cmd, node['host'], stdout, stderr))
+            raise RuntimeError(
+                "{} failed on node {} {} {}".format(cmd, node["host"], stdout, stderr)
+            )
 
-        print ("There have been changes to the GRUB config a", end=' ')
-        print ("reboot will be required.")
+        print("There have been changes to the GRUB config a", end=" ")
+        print("reboot will be required.")
         return -1
     else:
-        print ('\nThere are no changes to the GRUB config.')
+        print("\nThere are no changes to the GRUB config.")
 
     return 0
 
@@ -289,15 +292,15 @@ def autoconfig_apply(ask_questions=True):
     vutil = VPPUtil()
     pkgs = vutil.get_installed_vpp_pkgs()
     if len(pkgs) == 0:
-        print ("\nVPP is not installed, Install VPP with option 4.")
+        print("\nVPP is not installed, Install VPP with option 4.")
         return
 
     acfg = AutoConfig(rootdir, VPP_AUTO_CONFIGURATION_FILE)
 
     if ask_questions:
-        print ("\nWe are now going to configure your system(s).\n")
-        answer = autoconfig_yn("Are you sure you want to do this [Y/n]? ", 'y')
-        if answer == 'n':
+        print("\nWe are now going to configure your system(s).\n")
+        answer = autoconfig_yn("Are you sure you want to do this [Y/n]? ", "y")
+        if answer == "n":
             return
 
     nodes = acfg.get_nodes()
@@ -369,7 +372,9 @@ def autoconfig_dryrun(ask_questions=True):
     for i in nodes.items():
         node = i[1]
         if not acfg.has_interfaces(node):
-            print("\nThere are no VPP interfaces configured, please configure at least 1.")
+            print(
+                "\nThere are no VPP interfaces configured, please configure at least 1."
+            )
             return
 
     # Modify CPU
@@ -414,34 +419,31 @@ def autoconfig_install():
         pkgs = vutil.get_installed_vpp_pkgs()
 
         if len(pkgs) > 0:
-            print ("\nThese packages are installed on node {}"
-                   .format(node['host']))
-            print ("{:25} {}".format("Name", "Version"))
+            print("\nThese packages are installed on node {}".format(node["host"]))
+            print("{:25} {}".format("Name", "Version"))
             for pkg in pkgs:
                 try:
-                    print ("{:25} {}".format(
-                        pkg['name'], pkg['version']))
+                    print("{:25} {}".format(pkg["name"], pkg["version"]))
                 except KeyError:
-                    print ("{}".format(pkg['name']))
+                    print("{}".format(pkg["name"]))
 
             question = "\nDo you want to uninstall these "
             question += "packages [y/N]? "
-            answer = autoconfig_yn(question, 'n')
-            if answer == 'y':
+            answer = autoconfig_yn(question, "n")
+            if answer == "y":
                 logger.setLevel(logging.INFO)
                 vutil.uninstall_vpp(node)
         else:
-            print ("\nThere are no VPP packages on node {}."
-                   .format(node['host']))
+            print("\nThere are no VPP packages on node {}.".format(node["host"]))
             question = "Do you want to install VPP [Y/n]? "
-            answer = autoconfig_yn(question, 'y')
-            if answer == 'y':
+            answer = autoconfig_yn(question, "y")
+            if answer == "y":
                 question = "Do you want to install the release version [Y/n]? "
-                answer = autoconfig_yn(question, 'y')
-                if answer == 'y':
-                    branch = 'release'
+                answer = autoconfig_yn(question, "y")
+                if answer == "y":
+                    branch = "release"
                 else:
-                    branch = 'master'
+                    branch = "master"
                 logger.setLevel(logging.INFO)
                 vutil.install_vpp(node, branch)
 
@@ -486,9 +488,9 @@ def autoconfig_create_iperf_vm():
     """
 
     acfg = AutoConfig(rootdir, VPP_AUTO_CONFIGURATION_FILE)
-    acfg.destroy_iperf_vm('iperf-server')
+    acfg.destroy_iperf_vm("iperf-server")
     acfg.create_and_bridge_iperf_virtual_interface()
-    acfg.create_iperf_vm('iperf-server')
+    acfg.create_iperf_vm("iperf-server")
 
 
 def autoconfig_not_implemented():
@@ -497,7 +499,7 @@ def autoconfig_not_implemented():
 
     """
 
-    print ("\nThis Feature is not implemented yet....")
+    print("\nThis Feature is not implemented yet....")
 
 
 def autoconfig_basic_test_menu():
@@ -506,28 +508,28 @@ def autoconfig_basic_test_menu():
 
     """
 
-    basic_menu_text = '\nWhat would you like to do?\n\n\
+    basic_menu_text = "\nWhat would you like to do?\n\n\
 1) List/Create Simple IPv4 Setup\n\
 2) Create an iperf VM and Connect to VPP an interface\n\
-9 or q) Back to main menu.'
+9 or q) Back to main menu."
 
-    print ("{}".format(basic_menu_text))
+    print("{}".format(basic_menu_text))
 
     input_valid = False
-    answer = ''
+    answer = ""
     while not input_valid:
         answer = input("\nCommand: ")
         if len(answer) > 1:
-            print ("Please enter only 1 character.")
+            print("Please enter only 1 character.")
             continue
-        if re.findall(r'[Qq1-29]', answer):
+        if re.findall(r"[Qq1-29]", answer):
             input_valid = True
             answer = answer[0].lower()
         else:
-            print ("Please enter a character between 1 and 2 or 9.")
+            print("Please enter a character between 1 and 2 or 9.")
 
-        if answer == '9':
-            answer = 'q'
+        if answer == "9":
+            answer = "q"
 
     return answer
 
@@ -540,17 +542,17 @@ def autoconfig_basic_test():
     vutil = VPPUtil()
     pkgs = vutil.get_installed_vpp_pkgs()
     if len(pkgs) == 0:
-        print ("\nVPP is not installed, install VPP with option 4.")
+        print("\nVPP is not installed, install VPP with option 4.")
         return
 
-    answer = ''
-    while answer != 'q':
+    answer = ""
+    while answer != "q":
         answer = autoconfig_basic_test_menu()
-        if answer == '1':
+        if answer == "1":
             autoconfig_ipv4_setup()
-        elif answer == '2':
+        elif answer == "2":
             autoconfig_create_iperf_vm()
-        elif answer == '9' or answer == 'q':
+        elif answer == "9" or answer == "q":
             return
         else:
             autoconfig_not_implemented()
@@ -562,30 +564,32 @@ def autoconfig_main_menu():
 
     """
 
-    main_menu_text = '\nWhat would you like to do?\n\n\
+    main_menu_text = "\nWhat would you like to do?\n\n\
 1) Show basic system information\n\
 2) Dry Run (Saves the configuration files in {}/vpp/vpp-config/dryrun.\n\
 3) Full configuration (WARNING: This will change the system configuration)\n\
 4) List/Install/Uninstall VPP.\n\
-q) Quit'.format(rootdir, rootdir)
+q) Quit".format(
+        rootdir, rootdir
+    )
 
     # 5) Dry Run from {}/vpp/vpp-config/auto-config.yaml (will not ask questions).\n\
     # 6) Install QEMU patch (Needed when running openstack).\n\
 
-    print ("{}".format(main_menu_text))
+    print("{}".format(main_menu_text))
 
     input_valid = False
-    answer = ''
+    answer = ""
     while not input_valid:
         answer = input("\nCommand: ")
         if len(answer) > 1:
-            print ("Please enter only 1 character.")
+            print("Please enter only 1 character.")
             continue
-        if re.findall(r'[Qq1-4]', answer):
+        if re.findall(r"[Qq1-4]", answer):
             input_valid = True
             answer = answer[0].lower()
         else:
-            print ("Please enter a character between 1 and 4 or q.")
+            print("Please enter a character between 1 and 4 or q.")
 
     return answer
 
@@ -599,18 +603,18 @@ def autoconfig_main():
     # Setup
     autoconfig_setup()
 
-    answer = ''
-    while answer != 'q':
+    answer = ""
+    while answer != "q":
         answer = autoconfig_main_menu()
-        if answer == '1':
+        if answer == "1":
             autoconfig_show_system()
-        elif answer == '2':
+        elif answer == "2":
             autoconfig_dryrun()
-        elif answer == '3':
+        elif answer == "3":
             autoconfig_apply()
-        elif answer == '4':
+        elif answer == "4":
             autoconfig_install()
-        elif answer == 'q':
+        elif answer == "q":
             return
         else:
             autoconfig_not_implemented()
@@ -627,53 +631,65 @@ def autoconfig_setup(ask_questions=True):
     global rootdir
 
     distro = VPPUtil.get_linux_distro()
-    if distro[0] == 'Ubuntu':
-        rootdir = '/usr/local'
+    if distro[0] == "Ubuntu":
+        rootdir = "/usr/local"
     else:
-        rootdir = '/usr'
+        rootdir = "/usr"
 
     # If there is a system configuration file use that, if not use the initial auto-config file
     filename = rootdir + VPP_AUTO_CONFIGURATION_FILE
     if os.path.isfile(filename) is True:
         acfg = AutoConfig(rootdir, VPP_AUTO_CONFIGURATION_FILE)
     else:
-        raise RuntimeError('The Auto configuration file does not exist {}'.
-                           format(filename))
+        raise RuntimeError(
+            "The Auto configuration file does not exist {}".format(filename)
+        )
 
     if ask_questions:
-        print ("\nWelcome to the VPP system configuration utility")
+        print("\nWelcome to the VPP system configuration utility")
 
-        print ("\nThese are the files we will modify:")
-        print ("    /etc/vpp/startup.conf")
-        print ("    /etc/sysctl.d/80-vpp.conf")
-        print ("    /etc/default/grub")
+        print("\nThese are the files we will modify:")
+        print("    /etc/vpp/startup.conf")
+        print("    /etc/sysctl.d/80-vpp.conf")
+        print("    /etc/default/grub")
 
-        print (
+        print(
             "\nBefore we change them, we'll create working copies in "
-            "{}".format(rootdir + VPP_DRYRUNDIR))
-        print (
+            "{}".format(rootdir + VPP_DRYRUNDIR)
+        )
+        print(
             "Please inspect them carefully before applying the actual "
-            "configuration (option 3)!")
+            "configuration (option 3)!"
+        )
 
     nodes = acfg.get_nodes()
     for i in nodes.items():
         node = i[1]
 
-        if (os.path.isfile(rootdir + VPP_STARTUP_FILE) is not True) and \
-                (os.path.isfile(VPP_REAL_STARTUP_FILE) is True):
-            autoconfig_cp(node, VPP_REAL_STARTUP_FILE, '{}'.format(rootdir + VPP_STARTUP_FILE))
-        if (os.path.isfile(rootdir + VPP_HUGE_PAGE_FILE) is not True) and \
-                (os.path.isfile(VPP_REAL_HUGE_PAGE_FILE) is True):
-            autoconfig_cp(node, VPP_REAL_HUGE_PAGE_FILE, '{}'.format(rootdir + VPP_HUGE_PAGE_FILE))
-        if (os.path.isfile(rootdir + VPP_GRUB_FILE) is not True) and \
-                (os.path.isfile(VPP_REAL_GRUB_FILE) is True):
-            autoconfig_cp(node, VPP_REAL_GRUB_FILE, '{}'.format(rootdir + VPP_GRUB_FILE))
+        if (os.path.isfile(rootdir + VPP_STARTUP_FILE) is not True) and (
+            os.path.isfile(VPP_REAL_STARTUP_FILE) is True
+        ):
+            autoconfig_cp(
+                node, VPP_REAL_STARTUP_FILE, "{}".format(rootdir + VPP_STARTUP_FILE)
+            )
+        if (os.path.isfile(rootdir + VPP_HUGE_PAGE_FILE) is not True) and (
+            os.path.isfile(VPP_REAL_HUGE_PAGE_FILE) is True
+        ):
+            autoconfig_cp(
+                node, VPP_REAL_HUGE_PAGE_FILE, "{}".format(rootdir + VPP_HUGE_PAGE_FILE)
+            )
+        if (os.path.isfile(rootdir + VPP_GRUB_FILE) is not True) and (
+            os.path.isfile(VPP_REAL_GRUB_FILE) is True
+        ):
+            autoconfig_cp(
+                node, VPP_REAL_GRUB_FILE, "{}".format(rootdir + VPP_GRUB_FILE)
+            )
 
         # Be sure the uio_pci_generic driver is installed
-        cmd = 'modprobe uio_pci_generic'
+        cmd = "modprobe uio_pci_generic"
         (ret, stdout, stderr) = VPPUtil.exec_command(cmd)
         if ret != 0:
-            logging.warning('{} failed on node {} {}'. format(cmd, node['host'], stderr))
+            logging.warning("{} failed on node {} {}".format(cmd, node["host"], stderr))
 
 
 # noinspection PyUnresolvedReferences
@@ -707,10 +723,9 @@ def config_main():
 
     # Check for root
     if not os.geteuid() == 0:
-        sys.exit('\nPlease run the VPP Configuration Utility as root.')
+        sys.exit("\nPlease run the VPP Configuration Utility as root.")
 
-    if len(sys.argv) > 1 and ((sys.argv[1] == '-d') or (
-            sys.argv[1] == '--debug')):
+    if len(sys.argv) > 1 and ((sys.argv[1] == "-d") or (sys.argv[1] == "--debug")):
         logging.basicConfig(level=logging.DEBUG)
     else:
         logging.basicConfig(level=logging.ERROR)
@@ -720,37 +735,44 @@ def config_main():
     if len(sys.argv) == 1:
         autoconfig_main()
         return
-    elif len(sys.argv) == 2 and ((sys.argv[1] == '-d') or (
-            sys.argv[1] == '--debug')):
+    elif len(sys.argv) == 2 and ((sys.argv[1] == "-d") or (sys.argv[1] == "--debug")):
         autoconfig_main()
         return
 
     # There were arguments specified, so execute the utility using
     # command line arguments
-    description = 'The VPP configuration utility allows the user to '
-    'configure VPP in a simple and safe manner. The utility takes input '
-    'from the user or the specified .yaml file. The user should then '
-    'examine these files to be sure they are correct and then actually '
-    'apply the configuration. When run without arguments the utility run '
-    'in an interactive mode'
+    description = "The VPP configuration utility allows the user to "
+    "configure VPP in a simple and safe manner. The utility takes input "
+    "from the user or the specified .yaml file. The user should then "
+    "examine these files to be sure they are correct and then actually "
+    "apply the configuration. When run without arguments the utility run "
+    "in an interactive mode"
 
     main_parser = argparse.ArgumentParser(
-        prog='arg-test',
+        prog="arg-test",
         description=description,
-        epilog='See "%(prog)s help COMMAND" for help on a specific command.')
-    main_parser.add_argument('--apply', '-a', action='store_true',
-                             help='Apply the cofiguration.')
-    main_parser.add_argument('--dry-run', '-dr', action='store_true',
-                             help='Create the dryrun configuration files.')
-    main_parser.add_argument('--show', '-s', action='store_true',
-                             help='Shows basic system information')
-    main_parser.add_argument('--debug', '-d', action='count',
-                             help='Print debug output (multiple levels)')
+        epilog='See "%(prog)s help COMMAND" for help on a specific command.',
+    )
+    main_parser.add_argument(
+        "--apply", "-a", action="store_true", help="Apply the cofiguration."
+    )
+    main_parser.add_argument(
+        "--dry-run",
+        "-dr",
+        action="store_true",
+        help="Create the dryrun configuration files.",
+    )
+    main_parser.add_argument(
+        "--show", "-s", action="store_true", help="Shows basic system information"
+    )
+    main_parser.add_argument(
+        "--debug", "-d", action="count", help="Print debug output (multiple levels)"
+    )
 
     args = main_parser.parse_args()
 
     return execute_with_args(args)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     config_main()