Fix various pylint 1.5.4 warnings

+ DUTSetup.py:424 Else clause on loop without a break statement
+ InterfaceUtil.py:400 Else clause on loop without a break statement
+ QemuUtils.py:564 Wrong continued indentation
+ SetupDPDKTest.py: Locally enabling broad-except
+ VatExecutor.py: Catching too general exception Exception
+ ssh.py:95 No exception type(s) specified.
+ HTTPRequest.py: Tolerate HTTPCodes.OK
+ multiple: Drop ":returns: None" from docstrings.

There are still several warnings present:
- R0902(too-many-instance-attributes)
- R0912(too-many-branches)
- R0913(too-many-arguments)
- R0914(too-many-locals)
- R0915(too-many-statements)
- R0401(cyclic-import)

And there are multiple blocks of similar lines,
mainly across various Setup*Test.py files:
- R0801(duplicate-code)

Change-Id: I582575cb52b85d69d268e6374852f6e74bb71052
Signed-off-by: Vratko Polak <vrpolak@cisco.com>

15 files changed, 43 insertions, 45 deletions

diff --git a/resources/libraries/python/DPDK/DPDKTools.py b/resources/libraries/python/DPDK/DPDKTools.py
index a256ae5ddc..b0e67b7ab8 100644
--- a/resources/libraries/python/DPDK/DPDKTools.py
+++ b/resources/libraries/python/DPDK/DPDKTools.py
@@ -37,7 +37,6 @@ class DPDKTools(object):
         :type dut_node: dict
         :type dut_if1: str
         :type dut_if2: str
-        :returns: none
         :raises RuntimeError: If it fails to bind the interfaces to igb_uio.
         """
         if dut_node['type'] == NodeType.DUT:
@@ -72,7 +71,6 @@ class DPDKTools(object):
         :type dut_node: dict
         :type dut_if1: str
         :type dut_if2: str
-        :returns: none
         :raises RuntimeError: If it fails to cleanup the dpdk.
         """
         if dut_node['type'] == NodeType.DUT:
diff --git a/resources/libraries/python/DPDK/L2fwdTest.py b/resources/libraries/python/DPDK/L2fwdTest.py
index cfaa39991d..65ad6a53a4 100644
--- a/resources/libraries/python/DPDK/L2fwdTest.py
+++ b/resources/libraries/python/DPDK/L2fwdTest.py
@@ -39,7 +39,6 @@ class L2fwdTest(object):
         :type nb_cores: str
         :type queue_nums: str
         :type jumbo_frames: str
-        :returns: none
         :raises RuntimeError: If the script "run_l2fwd.sh" fails.
         """
         if dut_node['type'] == NodeType.DUT:
diff --git a/resources/libraries/python/DPDK/L3fwdTest.py b/resources/libraries/python/DPDK/L3fwdTest.py
index d7e9305391..15e656af07 100644
--- a/resources/libraries/python/DPDK/L3fwdTest.py
+++ b/resources/libraries/python/DPDK/L3fwdTest.py
@@ -44,7 +44,6 @@ class L3fwdTest(object):
         :type lcores_list: str
         :type queue_nums: str
         :type jumbo_frames: str
-        :returns: none
         """
         if dut_node['type'] == NodeType.DUT:
             adj_mac0, adj_mac1 = L3fwdTest.get_adj_mac(nodes_info, dut_node,
diff --git a/resources/libraries/python/DPDK/SetupDPDKTest.py b/resources/libraries/python/DPDK/SetupDPDKTest.py
index d94a383786..1e88f8d8c1 100644
--- a/resources/libraries/python/DPDK/SetupDPDKTest.py
+++ b/resources/libraries/python/DPDK/SetupDPDKTest.py
@@ -34,7 +34,9 @@ __all__ = ["SetupDPDKTest"]
 
 
 def pack_framework_dir():
-    """Pack the testing WS into temp file, return its name."""
+    """Pack the testing WS into temp file, return its name.
+
+    :raise RuntimeError: If command returns nonzero return code."""
 
     tmpfile = NamedTemporaryFile(suffix=".tgz", prefix="DPDK-testing-")
     file_name = tmpfile.name
@@ -50,7 +52,7 @@ def pack_framework_dir():
 
     return_code = proc.wait()
     if return_code != 0:
-        raise Exception("Could not pack testing framework.")
+        raise RuntimeError("Could not pack testing framework.")
 
     return file_name
 
@@ -81,6 +83,7 @@ def extract_tarball_at_node(tarball, node):
     :type tarball: str
     :type node: dict
     :returns: nothing
+    :raise RuntimeError: If command returns nonzero return code.
     """
     logger.console('Extracting tarball to {0} on {1}'.format(
         con.REMOTE_FW_DIR, node['host']))
@@ -92,7 +95,7 @@ def extract_tarball_at_node(tarball, node):
     (ret_code, _, stderr) = ssh.exec_command(cmd, timeout=30)
     if ret_code != 0:
         logger.error('Unpack error: {0}'.format(stderr))
-        raise Exception('Failed to unpack {0} at node {1}'.format(
+        raise RuntimeError('Failed to unpack {0} at node {1}'.format(
             tarball, node['host']))
 
 
@@ -103,6 +106,7 @@ def create_env_directory_at_node(node):
     :param node: Dictionary created from topology, will only install in the TG
     :type node: dict
     :returns: nothing
+    :raise RuntimeError: If command returns nonzero return code.
     """
     logger.console('Extracting virtualenv, installing requirements.txt '
                    'on {0}'.format(node['host']))
@@ -114,7 +118,7 @@ def create_env_directory_at_node(node):
         .format(con.REMOTE_FW_DIR), timeout=100)
     if ret_code != 0:
         logger.error('Virtualenv creation error: {0}'.format(stdout + stderr))
-        raise Exception('Virtualenv setup failed')
+        raise RuntimeError('Virtualenv setup failed')
     else:
         logger.console('Virtualenv created on {0}'.format(node['host']))
 
@@ -125,6 +129,7 @@ def install_dpdk_test(node):
     :param node: Dictionary created from topology
     :type node: dict
     :returns: nothing
+    :raise RuntimeError: If command returns nonzero return code.
     """
     arch = Topology.get_node_arch(node)
     logger.console('Install the DPDK on {0} ({1})'.format(node['host'],
@@ -139,11 +144,10 @@ def install_dpdk_test(node):
 
     if ret_code != 0:
         logger.error('Install the DPDK error: {0}'.format(stderr))
-        raise Exception('Install the DPDK failed')
+        raise RuntimeError('Install the DPDK failed')
     else:
         logger.console('Install the DPDK on {0} success!'.format(node['host']))
 
-#pylint: disable=broad-except
 def setup_node(args):
     """Run all set-up methods for a node.
 
@@ -168,13 +172,12 @@ def setup_node(args):
             install_dpdk_test(node)
         if node['type'] == NodeType.TG:
             create_env_directory_at_node(node)
-    except Exception as exc:
+    except RuntimeError as exc:
         logger.error("Node setup failed, error:'{0}'".format(exc.message))
         return False
     else:
         logger.console('Setup of node {0} done'.format(node['host']))
         return True
-#pylint: enable=broad-except
 
 def delete_local_tarball(tarball):
     """Delete local tarball to prevent disk pollution.
diff --git a/resources/libraries/python/DUTSetup.py b/resources/libraries/python/DUTSetup.py
index 9c78cfe6aa..d08704bba1 100644
--- a/resources/libraries/python/DUTSetup.py
+++ b/resources/libraries/python/DUTSetup.py
@@ -421,8 +421,7 @@ class DUTSetup(object):
                         return None
                 if name == 'Driver:':
                     return value
-        else:
-            return None
+        return None
 
     @staticmethod
     def kernel_module_verify(node, module, force_load=False):
diff --git a/resources/libraries/python/HTTPRequest.py b/resources/libraries/python/HTTPRequest.py
index a64513b9ba..0f650a89a1 100644
--- a/resources/libraries/python/HTTPRequest.py
+++ b/resources/libraries/python/HTTPRequest.py
@@ -33,7 +33,7 @@ from requests.auth import HTTPBasicAuth
 @unique
 class HTTPCodes(IntEnum):
     """HTTP status codes"""
-    OK = 200
+    OK = 200  # HTTP standard code name.  # pylint: disable=invalid-name
     ACCEPTED = 201
     UNAUTHORIZED = 401
     FORBIDDEN = 403
diff --git a/resources/libraries/python/InterfaceUtil.py b/resources/libraries/python/InterfaceUtil.py
index c0a8957935..aac78c9e44 100644
--- a/resources/libraries/python/InterfaceUtil.py
+++ b/resources/libraries/python/InterfaceUtil.py
@@ -316,7 +316,6 @@ class InterfaceUtil(object):
         :type node: dict
         :type pci_addr: str
         :type driver: str
-        :returns: None.
         :raises RuntimeError: If unbinding from the current driver fails.
         :raises RuntimeError: If binding to the new driver fails.
         """
@@ -397,9 +396,8 @@ class InterfaceUtil(object):
                         return None
                 if name == 'Driver:':
                     return value if value else None
-        else:
-            raise RuntimeError('Get interface driver for: {0}'
-                               .format(pci_addr))
+        raise RuntimeError('Get interface driver for: {0}'
+                           .format(pci_addr))
 
     @staticmethod
     def tg_set_interfaces_udev_rules(node):
diff --git a/resources/libraries/python/L2Util.py b/resources/libraries/python/L2Util.py
index 7954193b60..53c3b99c83 100644
--- a/resources/libraries/python/L2Util.py
+++ b/resources/libraries/python/L2Util.py
@@ -132,7 +132,6 @@ class L2Util(object):
         :type sw_if_index: int
         :type bd_id: int
         :type shg: int
-        :returns: None
         """
         VatExecutor.cmd_from_template(node, "l2_bd_add_sw_if_index.vat",
                                       bd_id=bd_id, sw_if_index=sw_if_index,
diff --git a/resources/libraries/python/PacketVerifier.py b/resources/libraries/python/PacketVerifier.py
index d1e7bbd229..978babf7ce 100644
--- a/resources/libraries/python/PacketVerifier.py
+++ b/resources/libraries/python/PacketVerifier.py
@@ -180,7 +180,6 @@ def packet_reader(interface_name, queue):
     :param queue: Queue in which this function will push incoming packets.
     :type interface_name: str
     :type queue: multiprocessing.Queue
-    :returns: None
     """
     sock = conf.L2listen(iface=interface_name, type=ETH_P_ALL)
 
diff --git a/resources/libraries/python/QemuUtils.py b/resources/libraries/python/QemuUtils.py
index 99fb7f4b8d..5821455cc3 100644
--- a/resources/libraries/python/QemuUtils.py
+++ b/resources/libraries/python/QemuUtils.py
@@ -560,8 +560,8 @@ class QemuUtils(object):
         pid = '-pidfile {}'.format(self._pid_file)
 
         # Run QEMU
-        cmd = '{0} {1} {2} {3} {4} {5} {6} {7} {8} {9} {10}'.format(bin_path,
-            self._qemu_opt.get('smp'), mem, ssh_fwd,
+        cmd = '{0} {1} {2} {3} {4} {5} {6} {7} {8} {9} {10}'.format(
+            bin_path, self._qemu_opt.get('smp'), mem, ssh_fwd,
             self._qemu_opt.get('options'), drive, qmp, serial, qga, graphic,
             pid)
         try:
diff --git a/resources/libraries/python/SFC/SFCTest.py b/resources/libraries/python/SFC/SFCTest.py
index 2584632af9..d4f77baa52 100644
--- a/resources/libraries/python/SFC/SFCTest.py
+++ b/resources/libraries/python/SFC/SFCTest.py
@@ -43,7 +43,6 @@ class SFCTest(object):
         :type if1_adj_mac: str
         :type if2_adj_mac: str
         :type testtype: str
-        :returns: none
         :raises RuntimeError: If the script execute fails.
         """
 
diff --git a/resources/libraries/python/SFC/VerifyPacket.py b/resources/libraries/python/SFC/VerifyPacket.py
index 90dfd375ca..a13c7601d5 100644
--- a/resources/libraries/python/SFC/VerifyPacket.py
+++ b/resources/libraries/python/SFC/VerifyPacket.py
@@ -66,7 +66,6 @@ class VerifyPacket(object):
 
         :param payload_data: the payload data in the packet.
         :type payload_data: str
-        :returns: none
         :raises RuntimeError: If the vxlan protocol field verify fails.
         """
         # get the vxlan packet and check it
@@ -87,7 +86,6 @@ class VerifyPacket(object):
         :param test_type: the functional test type.
         :type payload_data: str
         :type test_type: str
-        :returns: none
         :raises RuntimeError: If the vxlangpe and nsh protocol
                               field verify fails.
         """
@@ -171,7 +169,6 @@ class VerifyPacket(object):
         :type ether: scapy.Ether
         :type frame_size: Integer
         :type test_type: str
-        :returns: none
         :raises RuntimeError: If the packet field verify fails.
         """
 
diff --git a/resources/libraries/python/TLDK/UdpTest.py b/resources/libraries/python/TLDK/UdpTest.py
index 0571323dcf..b3f1b221e6 100644
--- a/resources/libraries/python/TLDK/UdpTest.py
+++ b/resources/libraries/python/TLDK/UdpTest.py
@@ -73,7 +73,6 @@ class UdpTest(object):
         :type file_prefix: str
         :type dest_ip: str
         :type is_ipv4: bool
-        :returns: none.
         :raises RuntimeError: If failed to execute udpfwd test on the dut node.
         """
         pci_address = Topology.get_interface_pci_addr(dut_node, dut_if)
diff --git a/resources/libraries/python/VatExecutor.py b/resources/libraries/python/VatExecutor.py
index 41e97e3901..d27e0677d3 100644
--- a/resources/libraries/python/VatExecutor.py
+++ b/resources/libraries/python/VatExecutor.py
@@ -204,6 +204,7 @@ class VatTerminal(object):
     __LINUX_PROMPT = (":~$ ", "~]$ ", "~]# ")
 
     def __init__(self, node, json_param=True):
+        """TODO: Should we document this constructor can raise RuntimeError?"""
         json_text = ' json' if json_param else ''
         self.json = json_param
         self._node = node
@@ -211,7 +212,7 @@ class VatTerminal(object):
         self._ssh.connect(self._node)
         try:
             self._tty = self._ssh.interactive_terminal_open()
-        except Exception:
+        except IOError:
             raise RuntimeError("Cannot open interactive terminal on node {0}".
                                format(self._node))
 
@@ -221,7 +222,7 @@ class VatTerminal(object):
                     self._tty,
                     'sudo -S {0}{1}'.format(Constants.VAT_BIN_NAME, json_text),
                     self.__VAT_PROMPT)
-            except Exception:
+            except IOError:
                 continue
             else:
                 break
@@ -253,9 +254,9 @@ class VatTerminal(object):
         """Execute command on the opened VAT terminal.
 
         :param cmd: Command to be executed.
-
         :returns: Command output in python representation of JSON format or
             None if not in JSON mode.
+        :raise RuntimeError: If VAT command execution fails.
         """
         VatHistory.add_to_vat_history(self._node, cmd)
         logger.debug("Executing command in VAT terminal: {0}".format(cmd))
@@ -263,7 +264,7 @@ class VatTerminal(object):
             out = self._ssh.interactive_terminal_exec_command(self._tty, cmd,
                                                               self.__VAT_PROMPT)
             self.vat_stdout = out
-        except Exception:
+        except IOError:
             self._exec_failure = True
             vpp_pid = get_vpp_pid(self._node)
             if vpp_pid:
diff --git a/resources/libraries/python/ssh.py b/resources/libraries/python/ssh.py
index 8c064e2729..fe4404b053 100644
--- a/resources/libraries/python/ssh.py
+++ b/resources/libraries/python/ssh.py
@@ -92,11 +92,11 @@ class SSH(object):
                          format(self._ssh.get_transport().getpeername()))
             logger.debug('Connections: {0}'.
                          format(str(SSH.__existing_connections)))
-        except:
+        except RuntimeError as exc:
             if attempts > 0:
                 self._reconnect(attempts-1)
             else:
-                raise
+                raise exc
 
     def disconnect(self, node):
         """Close SSH connection to the node.
@@ -236,8 +236,8 @@ class SSH(object):
     def interactive_terminal_open(self, time_out=30):
         """Open interactive terminal on a new channel on the connected Node.
 
-        :param time_out: Timeout in seconds.
-        :returns: SSH channel with opened terminal.
+        FIXME: Convert or document other possible exceptions, such as
+        socket.error or SSHException.
 
         .. warning:: Interruptingcow is used here, and it uses
            signal(SIGALRM) to let the operating system interrupt program
@@ -245,6 +245,10 @@ class SSH(object):
            handlers only apply to the main thread, so you cannot use this
            from other threads. You must not use this in a program that
            uses SIGALRM itself (this includes certain profilers)
+
+        :param time_out: Timeout in seconds.
+        :returns: SSH channel with opened terminal.
+        :raise IOError: If receive attempt results in socket.timeout.
         """
         chan = self._ssh.get_transport().open_session()
         chan.get_pty()
@@ -264,7 +268,8 @@ class SSH(object):
                     break
             except socket.timeout:
                 logger.error('Socket timeout: {0}'.format(buf))
-                raise Exception('Socket timeout: {0}'.format(buf))
+                # TODO: Find out which exception would callers appreciate here.
+                raise IOError('Socket timeout: {0}'.format(buf))
         return chan
 
     def interactive_terminal_exec_command(self, chan, cmd, prompt):
@@ -272,18 +277,19 @@ class SSH(object):
 
         interactive_terminal_open() method has to be called first!
 
-        :param chan: SSH channel with opened terminal.
-        :param cmd: Command to be executed.
-        :param prompt: Command prompt, sequence of characters used to
-        indicate readiness to accept commands.
-        :returns: Command output.
-
         .. warning:: Interruptingcow is used here, and it uses
            signal(SIGALRM) to let the operating system interrupt program
            execution. This has the following limitations: Python signal
            handlers only apply to the main thread, so you cannot use this
            from other threads. You must not use this in a program that
            uses SIGALRM itself (this includes certain profilers)
+
+        :param chan: SSH channel with opened terminal.
+        :param cmd: Command to be executed.
+        :param prompt: Command prompt, sequence of characters used to
+            indicate readiness to accept commands.
+        :returns: Command output.
+        :raise IOError: If receive attempt results in socket.timeout.
         """
         chan.sendall('{c}\n'.format(c=cmd))
         buf = ''
@@ -299,8 +305,9 @@ class SSH(object):
             except socket.timeout:
                 logger.error('Socket timeout during execution of command: '
                              '{0}\nBuffer content:\n{1}'.format(cmd, buf))
-                raise Exception('Socket timeout during execution of command: '
-                                '{0}\nBuffer content:\n{1}'.format(cmd, buf))
+                # TODO: Find out which exception would callers appreciate here.
+                raise IOError('Socket timeout during execution of command: '
+                              '{0}\nBuffer content:\n{1}'.format(cmd, buf))
         tmp = buf.replace(cmd.replace('\n', ''), '')
         for item in prompt:
             tmp.replace(item, '')
@@ -353,6 +360,7 @@ class SSH(object):
 def exec_cmd(node, cmd, timeout=600, sudo=False):
     """Convenience function to ssh/exec/return rc, out & err.
 
+    FIXME: Document :param, :type, :raise and similar.
     Returns (rc, stdout, stderr).
     """
     if node is None: