CSIT-841 Optimize cheking k8s POD state
[csit.git] / resources / libraries / python / VppConfigGenerator.py
index d4ef04e..2586202 100644 (file)
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""VPP Configuration File Generator library"""
+"""VPP Configuration File Generator library."""
 
 import re
 import time
 
-from robot.api import logger
-
 from resources.libraries.python.ssh import SSH
 from resources.libraries.python.topology import NodeType
 from resources.libraries.python.topology import Topology
 
 __all__ = ['VppConfigGenerator']
 
-#
-# VPP configuration template.
-# TODO: Do we need a better place for this? Somewhere in an external
-# (template) file?
-# Note: We're going to pass this through Python string Formatter, so
-# any literal curly braces need to be escaped.
-#
-VPP_SERVICE_NAME = "vpp"
-VPP_CONFIG_FILENAME = "/etc/vpp/startup.conf"
-DEFAULT_SOCKETMEM_CONFIG = "1024,1024"
-VPP_CONFIG_TEMPLATE = """
-unix {{
-  nodaemon
-  log /tmp/vpe.log
-  cli-listen localhost:5002
-  full-coredump
-}}
-
-api-trace {{
-  on
-}}
-{heapsizeconfig}
-cpu {{
-{cpuconfig}
-}}
-
-dpdk {{
-  socket-mem {socketmemconfig}
-  dev default {{
-  {rxqueuesconfig}
-  {txqueuesconfig}
-  }}
-{pciconfig}
-{nomultiseg}
-{enablevhostuser}
-}}
-
-ip6 {{
-  hash-buckets 2000000
-  heap-size 1G
-}}
-
-"""
-# End VPP configuration template.
-
 
 class VppConfigGenerator(object):
-    """VPP Configuration File Generator"""
+    """VPP Configuration File Generator."""
 
     def __init__(self):
+        """Initialize library."""
+        # VPP Node to apply configuration on
+        self._node = ''
+        # VPP Hostname
+        self._hostname = ''
+        # VPP Configuration
         self._nodeconfig = {}
+        # Serialized VPP Configuration
+        self._vpp_config = ''
+        # VPP Service name
+        self._vpp_service_name = 'vpp'
 
-    def add_pci_all_devices(self, node):
-        """Add all PCI devices from topology file to startup config
+    def set_node(self, node):
+        """Set DUT node.
 
-        :param node: DUT node
+        :param node: Node to store configuration on.
         :type node: dict
-        :return: nothing
+        :raises RuntimeError: If Node type is not DUT.
         """
-        for port in node['interfaces'].keys():
-            pci_addr = Topology.get_interface_pci_addr(node, port)
-            if pci_addr:
-                self.add_pci_device(node, pci_addr)
-
+        if node['type'] != NodeType.DUT:
+            raise RuntimeError('Startup config can only be applied to DUT'
+                               'node.')
+        self._node = node
+        self._hostname = Topology.get_node_hostname(node)
 
-    def add_pci_device(self, node, *pci_devices):
-        """Add PCI device configuration for node.
+    def get_config_str(self):
+        """Get dumped startup configuration in VPP config format.
 
-        :param node: DUT node.
-        :param pci_device: PCI devices (format 0000:00:00.0 or 00:00.0)
-        :type node: dict
-        :type pci_devices: tuple
-        :return: nothing
+        :returns: Startup configuration in VPP config format.
+        :rtype: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
+        self.dump_config(self._nodeconfig)
+        return self._vpp_config
+
+    def add_config_item(self, config, value, path):
+        """Add startup configuration item.
+
+        :param config: Startup configuration of node.
+        :param value: Value to insert.
+        :param path: Path where to insert item.
+        :type config: dict
+        :type value: str
+        :type path: list
+        """
+        if len(path) == 1:
+            config[path[0]] = value
+            return
+        if path[0] not in config:
+            config[path[0]] = {}
+        self.add_config_item(config[path[0]], value, path[1:])
+
+    def dump_config(self, obj, level=-1):
+        """Dump the startup configuration in VPP config format.
+
+        :param obj: Python Object to print.
+        :param level: Nested level for indentation.
+        :type obj: Obj
+        :type level: int
+        :returns: nothing
+        """
+        indent = '  '
+        if level >= 0:
+            self._vpp_config += '{}{{\n'.format((level) * indent)
+        if isinstance(obj, dict):
+            for key, val in obj.items():
+                if hasattr(val, '__iter__'):
+                    self._vpp_config += '{}{}\n'.format((level + 1) * indent,
+                                                        key)
+                    self.dump_config(val, level + 1)
+                else:
+                    self._vpp_config += '{}{} {}\n'.format((level + 1) * indent,
+                                                           key, val)
+        else:
+            for val in obj:
+                self._vpp_config += '{}{}\n'.format((level + 1) * indent, val)
+        if level >= 0:
+            self._vpp_config += '{}}}\n'.format(level * indent)
+
+    def add_unix_log(self, value='/tmp/vpe.log'):
+        """Add UNIX log configuration.
+
+        :param value: Log file.
+        :type value: str
+        """
+        path = ['unix', 'log']
+        self.add_config_item(self._nodeconfig, value, path)
 
-        # Specific device was given.
-        hostname = Topology.get_node_hostname(node)
+    def add_unix_cli_listen(self, value='localhost:5002'):
+        """Add UNIX cli-listen configuration.
 
+        :param value: CLI listen address and port.
+        :type value: str
+        """
+        path = ['unix', 'cli-listen']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def add_unix_nodaemon(self):
+        """Add UNIX nodaemon configuration."""
+        path = ['unix', 'nodaemon']
+        self.add_config_item(self._nodeconfig, '', path)
+
+    def add_unix_coredump(self):
+        """Add UNIX full-coredump configuration."""
+        path = ['unix', 'full-coredump']
+        self.add_config_item(self._nodeconfig, '', path)
+
+    def add_unix_exec(self, value):
+        """Add UNIX exec configuration."""
+        path = ['unix', 'exec']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def add_dpdk_dev(self, *devices):
+        """Add DPDK PCI device configuration.
+
+        :param devices: PCI device(s) (format xxxx:xx:xx.x)
+        :type devices: tuple
+        :raises ValueError: If PCI address format is not valid.
+        """
         pattern = re.compile("^[0-9A-Fa-f]{4}:[0-9A-Fa-f]{2}:"
                              "[0-9A-Fa-f]{2}\\.[0-9A-Fa-f]$")
-        for pci_device in pci_devices:
-            if not pattern.match(pci_device):
+        for device in devices:
+            if not pattern.match(device):
                 raise ValueError('PCI address {} to be added to host {} '
                                  'is not in valid format xxxx:xx:xx.x'.
-                                 format(pci_device, hostname))
-
-            if hostname not in self._nodeconfig:
-                self._nodeconfig[hostname] = {}
-            if 'pci_addrs' not in self._nodeconfig[hostname]:
-                self._nodeconfig[hostname]['pci_addrs'] = []
-            self._nodeconfig[hostname]['pci_addrs'].append(pci_device)
-            logger.debug('Adding PCI device {1} to {0}'.format(hostname,
-                                                               pci_device))
+                                 format(device, self._hostname))
+            path = ['dpdk', 'dev {0}'.format(device)]
+            self.add_config_item(self._nodeconfig, '', path)
 
-    def add_cpu_config(self, node, cpu_config):
-        """Add CPU configuration for node.
+    def add_dpdk_cryptodev(self, count):
+        """Add DPDK Crypto PCI device configuration.
 
-        :param node: DUT node.
-        :param cpu_config: CPU configuration option, as a string.
-        :type node: dict
-        :type cpu_config: str
-        :return: nothing
+        :param count: Number of crypto devices to add.
+        :type count: int
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname not in self._nodeconfig:
-            self._nodeconfig[hostname] = {}
-        if 'cpu_config' not in self._nodeconfig[hostname]:
-            self._nodeconfig[hostname]['cpu_config'] = []
-        self._nodeconfig[hostname]['cpu_config'].append(cpu_config)
-        logger.debug('Adding {} to hostname {} CPU config'.format(hostname,
-                                                                  cpu_config))
-
-    def add_socketmem_config(self, node, socketmem_config):
-        """Add Socket Memory configuration for node.
-
-        :param node: DUT node.
-        :param socketmem_config: Socket Memory configuration option,
-        as a string.
-        :type node: dict
-        :type socketmem_config: str
-        :return: nothing
+        cryptodev = Topology.get_cryptodev(self._node)
+        for i in range(count):
+            cryptodev_config = 'dev {0}'.format(
+                re.sub(r'\d.\d$', '1.'+str(i), cryptodev))
+            path = ['dpdk', cryptodev_config]
+            self.add_config_item(self._nodeconfig, '', path)
+        self.add_dpdk_uio_driver('igb_uio')
+
+    def add_dpdk_dev_default_rxq(self, value):
+        """Add DPDK dev default rxq configuration.
+
+        :param value: Default number of rxqs.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname not in self._nodeconfig:
-            self._nodeconfig[hostname] = {}
-        self._nodeconfig[hostname]['socketmem_config'] = socketmem_config
-        logger.debug('Setting hostname {} Socket Memory config to {}'.
-                     format(hostname, socketmem_config))
-
-    def add_heapsize_config(self, node, heapsize_config):
-        """Add Heap Size configuration for node.
-
-        :param node: DUT node.
-        :param heapsize_config: Heap Size configuration, as a string.
-        :type node: dict
-        :type heapsize_config: str
-        :return: nothing
+        path = ['dpdk', 'dev default', 'num-rx-queues']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def add_dpdk_dev_default_txq(self, value):
+        """Add DPDK dev default txq configuration.
+
+        :param value: Default number of txqs.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname not in self._nodeconfig:
-            self._nodeconfig[hostname] = {}
-        self._nodeconfig[hostname]['heapsize_config'] = heapsize_config
-        logger.debug('Setting hostname {} Heap Size config to {}'.
-                     format(hostname, heapsize_config))
-
-    def add_rxqueues_config(self, node, rxqueues_config):
-        """Add Rx Queues configuration for node.
-
-        :param node: DUT node.
-        :param rxqueues_config: Rxqueues configuration, as a string.
-        :type node: dict
-        :type rxqueues_config: str
-        :return: nothing
+        path = ['dpdk', 'dev default', 'num-tx-queues']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def add_dpdk_dev_default_rxd(self, value):
+        """Add DPDK dev default rxd configuration.
+
+        :param value: Default number of rxds.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if not hostname in self._nodeconfig:
-            self._nodeconfig[hostname] = {}
-        if not 'rxqueues_config' in self._nodeconfig[hostname]:
-            self._nodeconfig[hostname]['rxqueues_config'] = []
-        self._nodeconfig[hostname]['rxqueues_config'].append(rxqueues_config)
-        logger.debug('Setting hostname {} rxqueues config to {}'.\
-            format(hostname, rxqueues_config))
-
-    def add_no_multi_seg_config(self, node):
-        """Add No Multi Seg configuration for node.
-
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        path = ['dpdk', 'dev default', 'num-rx-desc']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def add_dpdk_dev_default_txd(self, value):
+        """Add DPDK dev default txd configuration.
+
+        :param value: Default number of txds.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if not hostname in self._nodeconfig:
-            self._nodeconfig[hostname] = {}
-        if not 'no_multi_seg_config' in self._nodeconfig[hostname]:
-            self._nodeconfig[hostname]['no_multi_seg_config'] = []
-        self._nodeconfig[hostname]['no_multi_seg_config'].append(
-            "no-multi-seg")
-        logger.debug('Setting hostname {} config with {}'.\
-            format(hostname, "no-multi-seg"))
-
-    def add_enable_vhost_user_config(self, node):
-        """Add enable-vhost-user configuration for node.
-
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        path = ['dpdk', 'dev default', 'num-tx-desc']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def add_dpdk_socketmem(self, value):
+        """Add DPDK socket memory configuration.
+
+        :param value: Socket memory size.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if not hostname in self._nodeconfig:
-            self._nodeconfig[hostname] = {}
-        if not 'enable_vhost_user' in self._nodeconfig[hostname]:
-            self._nodeconfig[hostname]['enable_vhost_user'] = []
-        self._nodeconfig[hostname]['enable_vhost_user'].append(
-            "enable-vhost-user")
-        logger.debug('Setting hostname {} config with {}'.\
-            format(hostname, "enable-vhost-user"))
-
-    def remove_all_pci_devices(self, node):
-        """Remove PCI device configuration from node.
-
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        path = ['dpdk', 'socket-mem']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def add_dpdk_uio_driver(self, value):
+        """Add DPDK uio-driver configuration.
+
+        :param value: DPDK uio-driver configuration.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname in self._nodeconfig:
-            self._nodeconfig[hostname]['pci_addrs'] = []
-        logger.debug('Clearing all PCI devices for hostname {}.'.
-                     format(hostname))
+        path = ['dpdk', 'uio-driver']
+        self.add_config_item(self._nodeconfig, value, path)
 
-    def remove_all_cpu_config(self, node):
-        """Remove CPU configuration from node.
+    def add_cpu_main_core(self, value):
+        """Add CPU main core configuration.
 
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        :param value: Main core option.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname in self._nodeconfig:
-            self._nodeconfig[hostname]['cpu_config'] = []
-        logger.debug('Clearing all CPU config for hostname {}.'.
-                     format(hostname))
+        path = ['cpu', 'main-core']
+        self.add_config_item(self._nodeconfig, value, path)
 
-    def remove_socketmem_config(self, node):
-        """Remove Socket Memory configuration from node.
+    def add_cpu_corelist_workers(self, value):
+        """Add CPU corelist-workers configuration.
 
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        :param value: Corelist-workers option.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname in self._nodeconfig:
-            self._nodeconfig[hostname].pop('socketmem_config', None)
-        logger.debug('Clearing Socket Memory config for hostname {}.'.
-                     format(hostname))
+        path = ['cpu', 'corelist-workers']
+        self.add_config_item(self._nodeconfig, value, path)
 
-    def remove_heapsize_config(self, node):
-        """Remove Heap Size configuration from node.
+    def add_heapsize(self, value):
+        """Add Heapsize configuration.
 
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        :param value: Amount of heapsize.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname in self._nodeconfig:
-            self._nodeconfig[hostname].pop('heapsize_config', None)
-        logger.debug('Clearing Heap Size config for hostname {}.'.
-                     format(hostname))
+        path = ['heapsize']
+        self.add_config_item(self._nodeconfig, value, path)
 
-    def remove_rxqueues_config(self, node):
-        """Remove Rxqueues configuration from node.
+    def add_api_trace(self):
+        """Add API trace configuration."""
+        path = ['api-trace', 'on']
+        self.add_config_item(self._nodeconfig, '', path)
 
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+    def add_ip6_hash_buckets(self, value):
+        """Add IP6 hash buckets configuration.
+
+        :param value: Number of IP6 hash buckets.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname in self._nodeconfig:
-            self._nodeconfig[hostname]['rxqueues_config'] = []
-        logger.debug('Clearing rxqueues config for hostname {}.'.\
-            format(hostname))
+        path = ['ip6', 'hash-buckets']
+        self.add_config_item(self._nodeconfig, value, path)
 
-    def remove_no_multi_seg_config(self, node):
-        """Remove No Multi Seg configuration from node.
+    def add_ip6_heap_size(self, value):
+        """Add IP6 heap-size configuration.
 
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        :param value: IP6 Heapsize amount.
+        :type value: str
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname in self._nodeconfig:
-            self._nodeconfig[hostname]['no_multi_seg_config'] = []
-        logger.debug('Clearing No Multi Seg config for hostname {}.'.\
-            format(hostname))
+        path = ['ip6', 'heap-size']
+        self.add_config_item(self._nodeconfig, value, path)
 
-    def remove_enable_vhost_user_config(self, node):
-        """Remove enable-vhost-user configuration from node.
+    def add_plugin_disable(self, *plugins):
+        """Add plugin disable for specific plugin.
 
-        :param node: DUT node.
-        :type node: dict
-        :return: nothing
+        :param plugins: Plugin(s) to disable.
+        :type plugins: list
         """
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-        if hostname in self._nodeconfig:
-            self._nodeconfig[hostname]['enable_vhost_user'] = []
-        logger.debug('Clearing enable-vhost-user config for hostname {}.'.\
-            format(hostname))
-
-    def apply_config(self, node, waittime=5, retries=12):
+        for plugin in plugins:
+            path = ['plugins', 'plugin {0}'.format(plugin), 'disable']
+            self.add_config_item(self._nodeconfig, ' ', path)
+
+    def add_dpdk_no_multi_seg(self):
+        """Add DPDK no-multi-seg configuration."""
+        path = ['dpdk', 'no-multi-seg']
+        self.add_config_item(self._nodeconfig, '', path)
+
+    def add_nat(self, value='deterministic'):
+        """Add NAT configuration.
+
+        :param value: NAT mode.
+        :type value: str
+        """
+        path = ['nat']
+        self.add_config_item(self._nodeconfig, value, path)
+
+    def apply_config(self, filename='/etc/vpp/startup.conf', waittime=5,
+                     retries=12, restart_vpp=True):
         """Generate and apply VPP configuration for node.
 
         Use data from calls to this class to form a startup.conf file and
         replace /etc/vpp/startup.conf with it on node.
 
-        :param node: DUT node.
+        :param filename: Startup configuration file name.
         :param waittime: Time to wait for VPP to restart (default 5 seconds).
         :param retries: Number of times (default 12) to re-try waiting.
-        :type node: dict
+        :param restart_vpp: Whether to restart VPP.
+        :type filename: str
         :type waittime: int
         :type retries: int
+        :type restart_vpp: bool.
+        :raises RuntimeError: If writing config file failed, or restarting of
+        VPP failed.
         """
-
-        if node['type'] != NodeType.DUT:
-            raise ValueError('Node type is not a DUT')
-        hostname = Topology.get_node_hostname(node)
-
-        cpuconfig = ""
-        pciconfig = ""
-        socketmemconfig = DEFAULT_SOCKETMEM_CONFIG
-        heapsizeconfig = ""
-        rxqueuesconfig = ""
-        txqueuesconfig = ""
-        nomultiseg = ""
-        enablevhostuser = ""
-
-        if hostname in self._nodeconfig:
-            cfg = self._nodeconfig[hostname]
-            if 'cpu_config' in cfg:
-                cpuconfig = "  " + "\n  ".join(cfg['cpu_config'])
-
-            if 'pci_addrs' in cfg:
-                pciconfig = "  dev " + "\n  dev ".join(cfg['pci_addrs'])
-
-            if 'socketmem_config' in cfg:
-                socketmemconfig = cfg['socketmem_config']
-
-            if 'heapsize_config' in cfg:
-                heapsizeconfig = "\nheapsize {}\n".\
-                    format(cfg['heapsize_config'])
-
-            if 'rxqueues_config' in cfg:
-                rxqueuesconfig = "  " + "\n  ".join(cfg['rxqueues_config'])
-
-            if 'no_multi_seg_config' in cfg:
-                nomultiseg = "  " + "\n  ".join(cfg['no_multi_seg_config'])
-
-            if 'enable_vhost_user' in cfg:
-                enablevhostuser = "  " + "\n  ".join(cfg['enable_vhost_user'])
-
-        vppconfig = VPP_CONFIG_TEMPLATE.format(cpuconfig=cpuconfig,
-                                               pciconfig=pciconfig,
-                                               socketmemconfig=socketmemconfig,
-                                               heapsizeconfig=heapsizeconfig,
-                                               rxqueuesconfig=rxqueuesconfig,
-                                               txqueuesconfig=txqueuesconfig,
-                                               nomultiseg=nomultiseg,
-                                               enablevhostuser=enablevhostuser)
-
-        logger.debug('Writing VPP config to host {}: "{}"'.format(hostname,
-                                                                  vppconfig))
+        self.dump_config(self._nodeconfig)
 
         ssh = SSH()
-        ssh.connect(node)
+        ssh.connect(self._node)
 
-        # We're using this "| sudo tee" construct because redirecting
-        # a sudo'd outut ("sudo echo xxx > /path/to/file") does not
-        # work on most platforms...
-        (ret, stdout, stderr) = \
-            ssh.exec_command('echo "{0}" | sudo tee {1}'.
-                             format(vppconfig, VPP_CONFIG_FILENAME))
+        (ret, _, _) = \
+            ssh.exec_command('echo "{config}" | sudo tee {filename}'.
+                             format(config=self._vpp_config,
+                                    filename=filename))
 
         if ret != 0:
-            logger.debug('Writing config file failed to node {}'.
-                         format(hostname))
-            logger.debug('stdout: {}'.format(stdout))
-            logger.debug('stderr: {}'.format(stderr))
             raise RuntimeError('Writing config file failed to node {}'.
-                               format(hostname))
-
-        # Instead of restarting, we'll do separate start and stop
-        # actions. This way we don't care whether VPP was running
-        # to begin with.
-        ssh.exec_command('sudo initctl stop {}'.format(VPP_SERVICE_NAME))
-        (ret, stdout, stderr) = \
-            ssh.exec_command('sudo initctl start {}'.format(VPP_SERVICE_NAME))
-        if ret != 0:
-            logger.debug('Restarting VPP failed on node {}'.
-                         format(hostname))
-            logger.debug('stdout: {}'.format(stdout))
-            logger.debug('stderr: {}'.format(stderr))
-            raise RuntimeError('Restarting VPP failed on node {}'.
-                               format(hostname))
-
-        # Sleep <waittime> seconds, up to <retry> times,
-        # and verify if VPP is running.
-        vpp_is_running = False
-        retries_left = retries
-        while (not vpp_is_running) and (retries_left > 0):
-            time.sleep(waittime)
-            retries_left -= 1
-
-            # FIXME: Need to find a good way to check if VPP is operational.
-            #
-            # If VatTerminal/VatExecutor is anything like vppctl or
-            # vpp_api_test, then in case VPP is NOT running it will block for
-            # 30 seconds or so and not even return if VPP becomes alive during
-            # that time. This makes it unsuitable in this case. We either need
-            # a call that returns immediately, indicating whether VPP is
-            # healthy or not, or a call that waits (up to a defined length
-            # of time) and returns immediately if VPP is or becomes healthy.
-            (ret, stdout, stderr) = \
-                ssh.exec_command('echo show hardware-interfaces | '
-                                 'nc 0 5002')
-
-            if ret == 0:
-                vpp_is_running = True
+                               format(self._hostname))
+
+        if restart_vpp:
+            # Instead of restarting, we'll do separate start and stop
+            # actions. This way we don't care whether VPP was running
+            # to begin with.
+            ssh.exec_command('sudo service {} stop'
+                             .format(self._vpp_service_name))
+            (ret, _, _) = \
+                ssh.exec_command('sudo service {} start'
+                                 .format(self._vpp_service_name))
+            if ret != 0:
+                raise RuntimeError('Restarting VPP failed on node {}'.
+                                   format(self._hostname))
+
+            # Sleep <waittime> seconds, up to <retry> times,
+            # and verify if VPP is running.
+            for _ in range(retries):
+                time.sleep(waittime)
+                (ret, _, _) = \
+                    ssh.exec_command('echo show hardware-interfaces | '
+                                     'nc 0 5002 || echo "VPP not yet running"')
+                if ret == 0:
+                    break
             else:
-                logger.debug('VPP not yet running, {} retries left'.
-                             format(retries_left))
-        if retries_left == 0:
-            raise RuntimeError('VPP failed to restart on node {}'.
-                               format(hostname))
-        logger.debug('VPP interfaces found on node {}'.
-                     format(stdout))
+                raise RuntimeError('VPP failed to restart on node {}'.
+                                   format(self._hostname))