opcua.server.Server

Complexity

Total Complexity

37

Size/Duplication

Total Lines	302
Duplicated Lines	0 %

Test Coverage

Coverage

84.67%

29 Methods

Rating	Name	Duplication	Size	Complexity
A	delete_nodes()	0	2	1
A	get_endpoints()	0	2	1
B	_setup_server_nodes()	0	29	3
A	set_server_name()	0	2	1
A	start()	0	9	1
A	__init__()	0	20	1
A	import_xml()	0	6	1
A	get_objects_node()	0	5	1
A	load_certificate()	0	5	1
A	create_subscription()	0	14	1
A	find_servers()	0	10	2
A	get_server_node()	0	5	1
B	_set_endpoints()	0	35	2
A	unregister_to_discovery()	0	6	1
A	get_event_object()	0	6	1
A	_renew_registration()	0	4	2
A	load_private_key()	0	2	1
A	stop()	0	8	2
A	register_namespace()	0	9	1
A	get_namespace_index()	0	6	1
A	allow_remote_admin()	0	5	1
A	get_node()	0	5	1
A	get_client_to_discovery()	0	7	1
A	disable_clock()	0	6	1
A	register_to_discovery()	0	16	3
A	get_namespace_array()	0	6	1
A	set_endpoint()	0	2	1
A	set_application_uri()	0	9	1
A	get_root_node()	0	5	1

"""
High level interface to pure python OPC-UA server
"""

import logging
try:
    from urllib.parse import urlparse
except ImportError:
    from urlparse import urlparse


from opcua import ua
#from opcua.binary_server import BinaryServer
from opcua.server.binary_server_asyncio import BinaryServer
from opcua.server.internal_server import InternalServer
from opcua.common.node import Node
from opcua.common.event import Event
from opcua.common.subscription import Subscription
from opcua.common import xmlimporter
from opcua.common.manage_nodes import delete_nodes
from opcua.client.client import Client
from opcua.crypto import security_policies
use_crypto = True
try:
    from opcua.crypto import uacrypto
except ImportError:
    print("cryptography is not installed, use of crypto disabled")
    use_crypto = False


class Server(object):

    """
    High level Server class
    Create an opcua server with default values
    The class is very short. Users are adviced to read the code.
    Create your own namespace and then populate your server address space
    using use the get_root() or get_objects() to get Node objects.
    and get_event_object() to fire events.
    Then start server. See example_server.py
    All methods are threadsafe


    :ivar application_uri:
    :vartype application_uri: uri
    :ivar product_uri:
    :vartype product_uri: uri
    :ivar name:
    :vartype name: string
    :ivar default_timeout: timout in milliseconds for sessions and secure channel
    :vartype default_timeout: int
    :ivar iserver: internal server object
    :vartype default_timeout: InternalServer
    :ivar bserver: binary protocol server
    :vartype bserver: BinaryServer

    """

    def __init__(self):
        self.logger = logging.getLogger(__name__)
        self.endpoint = urlparse("opc.tcp://0.0.0.0:4840/freeopcua/server/")
        self.application_uri = "urn:freeopcua:python:server"
        self.product_uri = "urn:freeopcua.github.no:python:server"
        self.name = "FreeOpcUa Python Server"
        self.application_type = ua.ApplicationType.ClientAndServer
        self.default_timeout = 3600000
        self.iserver = InternalServer()
        self.bserver = None
        self._discovery_clients = {}
        self._discovery_period = 60
        self.certificate = None
        self.private_key = None
        self._policies = []

        # setup some expected values
        self.register_namespace(self.application_uri)
        sa_node = self.get_node(ua.NodeId(ua.ObjectIds.Server_ServerArray))
        sa_node.set_value([self.application_uri])

    def load_certificate(self, path):
        """
        load server certificate from file, either pem or der
        """
        self.certificate = uacrypto.load_certificate(path)

    def load_private_key(self, path):
        self.private_key = uacrypto.load_private_key(path)

    def disable_clock(self, val=True):
        """
        for debugging you may want to disable clock that write every second
        to address space
        """
        self.iserver.disabled_clock = val

    def set_application_uri(self, uri):
        """
        Set application/server URI.
        This uri is supposed to be unique. If you intent to register
        your server to a discovery server, it really should be unique in
        your system!
        default is : "urn:freeopcua:python:server"
        """
        self.application_uri = uri

    def find_servers(self, uris=None):
        """
        find_servers. mainly implemented for simmetry with client
        """
        if uris is None:
            uris = []
        params = ua.FindServersParameters()
        params.EndpointUrl = self.endpoint.geturl()
        params.ServerUris = uris
        return self.iserver.find_servers(params)

    def register_to_discovery(self, url="opc.tcp://localhost:4840", period=60):
        """
        Register to an OPC-UA Discovery server. Registering must be renewed at
        least every 10 minutes, so this method will use our asyncio thread to
        re-register every period seconds
        if period is 0 registration is not automatically renewed
        """
        # FIXME: habe a period per discovery 
        if url in self._discovery_clients:
            self._discovery_clients[url].disconnect()
        self._discovery_clients[url] = Client(url)
        self._discovery_clients[url].connect()
        self._discovery_clients[url].register_server(self)
        self._discovery_period = period
        if period:
            self.iserver.loop.call_soon(self._renew_registration)

    def unregister_to_discovery(self, url="opc.tcp://localhost:4840"):
        """
        stop registration thread
        """
        # FIXME: is there really no way to deregister?
        self._discovery_clients[url].disconnect()

    def _renew_registration(self):
        for client in self._discovery_clients.values():
            client.register_server(self)
            self.iserver.loop.call_later(self._discovery_period, self._renew_registration)

    def get_client_to_discovery(self, url="opc.tcp://localhost:4840"):
        """
        Create a client to discovery server and return it
        """
        client = Client(url)
        client.connect()
        return client

    def allow_remote_admin(self, allow):
        """
        Enable or disable the builtin Admin user from network clients
        """
        self.iserver.allow_remote_admin = allow

    def set_endpoint(self, url):
        self.endpoint = urlparse(url)

    def get_endpoints(self):
        return self.iserver.get_endpoints()

    def _setup_server_nodes(self):
        # to be called just before starting server since it needs all parameters to be setup
        self._set_endpoints()
        self._policies = [ua.SecurityPolicyFactory()]
        if self.certificate and self.private_key:
            self._set_endpoints(security_policies.SecurityPolicyBasic128Rsa15,
                                ua.MessageSecurityMode.SignAndEncrypt)
            self._policies.append(ua.SecurityPolicyFactory(
                                security_policies.SecurityPolicyBasic128Rsa15,
                                ua.MessageSecurityMode.SignAndEncrypt,
                                self.certificate, self.private_key))
            self._set_endpoints(security_policies.SecurityPolicyBasic128Rsa15,
                                ua.MessageSecurityMode.Sign)
            self._policies.append(ua.SecurityPolicyFactory(
                                security_policies.SecurityPolicyBasic128Rsa15,
                                ua.MessageSecurityMode.Sign,
                                self.certificate, self.private_key))
            self._set_endpoints(security_policies.SecurityPolicyBasic256,
                                ua.MessageSecurityMode.SignAndEncrypt)
            self._policies.append(ua.SecurityPolicyFactory(
                                security_policies.SecurityPolicyBasic256,
                                ua.MessageSecurityMode.SignAndEncrypt,
                                self.certificate, self.private_key))
            self._set_endpoints(security_policies.SecurityPolicyBasic256,
                                ua.MessageSecurityMode.Sign)
            self._policies.append(ua.SecurityPolicyFactory(
                                security_policies.SecurityPolicyBasic256,
                                ua.MessageSecurityMode.Sign,
                                self.certificate, self.private_key))

    def _set_endpoints(self, policy=ua.SecurityPolicy, mode=ua.MessageSecurityMode.None_):
        idtoken = ua.UserTokenPolicy()
        idtoken.PolicyId = 'anonymous'
        idtoken.TokenType = ua.UserTokenType.Anonymous

        idtoken2 = ua.UserTokenPolicy()
        idtoken2.PolicyId = 'certificate_basic256'
        idtoken2.TokenType = ua.UserTokenType.Certificate

        idtoken3 = ua.UserTokenPolicy()
        idtoken3.PolicyId = 'certificate_basic128'
        idtoken3.TokenType = ua.UserTokenType.Certificate

        idtoken4 = ua.UserTokenPolicy()
        idtoken4.PolicyId = 'username'
        idtoken4.TokenType = ua.UserTokenType.UserName

        appdesc = ua.ApplicationDescription()
        appdesc.ApplicationName = ua.LocalizedText(self.name)
        appdesc.ApplicationUri = self.application_uri
        appdesc.ApplicationType = self.application_type
        appdesc.ProductUri = self.product_uri
        appdesc.DiscoveryUrls.append(self.endpoint.geturl())

        edp = ua.EndpointDescription()
        edp.EndpointUrl = self.endpoint.geturl()
        edp.Server = appdesc
        if self.certificate:
            edp.ServerCertificate = uacrypto.der_from_x509(self.certificate)
        edp.SecurityMode = mode
        edp.SecurityPolicyUri = policy.URI
        edp.UserIdentityTokens = [idtoken, idtoken2, idtoken3]
        edp.TransportProfileUri = 'http://opcfoundation.org/UA-Profile/Transport/uatcp-uasc-uabinary'
        edp.SecurityLevel = 0
        self.iserver.add_endpoint(edp)

    def set_server_name(self, name):
        self.name = name

    def start(self):
        """
        Start to listen on network
        """
        self._setup_server_nodes()
        self.iserver.start()
        self.bserver = BinaryServer(self.iserver, self.endpoint.hostname, self.endpoint.port)
        self.bserver.set_policies(self._policies)
        self.bserver.start()

    def stop(self):
        """
        Stop server
        """
        for client in self._discovery_clients.values():
            client.disconnect()
        self.bserver.stop()
        self.iserver.stop()

    def get_root_node(self):
        """
        Get Root node of server. Returns a Node object.
        """
        return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.RootFolder))

    def get_objects_node(self):
        """
        Get Objects node of server. Returns a Node object.
        """
        return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.ObjectsFolder))

    def get_server_node(self):
        """
        Get Server node of server. Returns a Node object.
        """
        return self.get_node(ua.TwoByteNodeId(ua.ObjectIds.Server))

    def get_node(self, nodeid):
        """
        Get a specific node using NodeId object or a string representing a NodeId
        """
        return Node(self.iserver.isession, nodeid)

    def create_subscription(self, period, handler):
        """
        Create a subscription.
        returns a Subscription object which allow
        to subscribe to events or data on server
        """
        params = ua.CreateSubscriptionParameters()
        params.RequestedPublishingInterval = period
        params.RequestedLifetimeCount = 3000
        params.RequestedMaxKeepAliveCount = 10000
        params.MaxNotificationsPerPublish = 0
        params.PublishingEnabled = True
        params.Priority = 0
        return Subscription(self.iserver.isession, params, handler)

    def get_namespace_array(self):
        """
        get all namespace defined in server
        """
        ns_node = self.get_node(ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
        return ns_node.get_value()

    def register_namespace(self, uri):
        """
        Register a new namespace. Nodes should in custom namespace, not 0.
        """
        ns_node = self.get_node(ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
        uries = ns_node.get_value()
        uries.append(uri)
        ns_node.set_value(uries)
        return (len(uries) - 1)

    def get_namespace_index(self, uri):
        """
        get index of a namespace using its uri
        """
        uries = self.get_namespace_array()
        return uries.index(uri)

    def get_event_object(self, etype=ua.ObjectIds.BaseEventType, source=ua.ObjectIds.Server):
        """
        Returns an event object using an event type from address space.
        Use this object to fire events
        """
        return Event(self.iserver.isession, etype, source)

    def import_xml(self, path):
        """
        import nodes defined in xml
        """
        importer = xmlimporter.XmlImporter(self.iserver.node_mgt_service)
        importer.import_xml(path)

    def delete_nodes(self, nodes, recursive=False):
        return delete_nodes(self.iserver.isession, nodes, recursive)