+"""
+Copyright (c) 2015 SONATA-NFV and Paderborn University
+ALL RIGHTS RESERVED.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
+nor the names of its contributors may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+This work has been performed in the framework of the SONATA project,
+funded by the European Commission under Grant number 671517 through
+the Horizon 2020 and 5G-PPP programmes. The authors would like to
+acknowledge the contributions of their colleagues of the SONATA
+partner consortium (www.sonata-nfv.eu).
+"""
+"""
+This module implements a simple REST API that behaves like SONATA's gatekeeper.
+
+It is only used to support the development of SONATA's SDK tools and to demonstrate
+the year 1 version of the emulator until the integration with WP4's orchestrator is done.
+"""
+
+import logging
+import os
+import uuid
+import hashlib
+import zipfile
+import yaml
+import threading
+from docker import Client as DockerClient
+from flask import Flask, request
+import flask_restful as fr
+from collections import defaultdict
+import pkg_resources
+
+logging.basicConfig()
+LOG = logging.getLogger("sonata-dummy-gatekeeper")
+LOG.setLevel(logging.DEBUG)
+logging.getLogger("werkzeug").setLevel(logging.WARNING)
+
+GK_STORAGE = "/tmp/son-dummy-gk/"
+UPLOAD_FOLDER = os.path.join(GK_STORAGE, "uploads/")
+CATALOG_FOLDER = os.path.join(GK_STORAGE, "catalog/")
+
+# Enable Dockerfile build functionality
+BUILD_DOCKERFILE = False
+
+# flag to indicate that we run without the emulator (only the bare API for integration testing)
+GK_STANDALONE_MODE = False
+
+# should a new version of an image be pulled even if its available
+FORCE_PULL = False
+
+# Automatically deploy SAPs (endpoints) of the service as new containers
+# Attention: This is not a configuration switch but a global variable! Don't change its default value.
+DEPLOY_SAP = False
+
+# flag to indicate if we use bidirectional forwarding rules in the automatic chaining process
+BIDIRECTIONAL_CHAIN = False
+
+class Gatekeeper(object):
+
+ def __init__(self):
+ self.services = dict()
+ self.dcs = dict()
+ self.vnf_counter = 0 # used to generate short names for VNFs (Mininet limitation)
+ LOG.info("Create SONATA dummy gatekeeper.")
+
+ def register_service_package(self, service_uuid, service):
+ """
+ register new service package
+ :param service_uuid
+ :param service object
+ """
+ self.services[service_uuid] = service
+ # lets perform all steps needed to onboard the service
+ service.onboard()
+
+ def get_next_vnf_name(self):
+ self.vnf_counter += 1
+ return "vnf%d" % self.vnf_counter
+
+
+class Service(object):
+ """
+ This class represents a NS uploaded as a *.son package to the
+ dummy gatekeeper.
+ Can have multiple running instances of this service.
+ """
+
+ def __init__(self,
+ service_uuid,
+ package_file_hash,
+ package_file_path):
+ self.uuid = service_uuid
+ self.package_file_hash = package_file_hash
+ self.package_file_path = package_file_path
+ self.package_content_path = os.path.join(CATALOG_FOLDER, "services/%s" % self.uuid)
+ self.manifest = None
+ self.nsd = None
+ self.vnfds = dict()
+ self.local_docker_files = dict()
+ self.remote_docker_image_urls = dict()
+ self.instances = dict()
+ self.vnf_name2docker_name = dict()
+ self.sap_identifiers = set()
+ # lets generate a set of subnet configurations used for e-line chaining setup
+ self.eline_subnets_src = generate_subnet_strings(50, start=200, subnet_size=24, ip=1)
+ self.eline_subnets_dst = generate_subnet_strings(50, start=200, subnet_size=24, ip=2)
+
+
+ def onboard(self):
+ """
+ Do all steps to prepare this service to be instantiated
+ :return:
+ """
+ # 1. extract the contents of the package and store them in our catalog
+ self._unpack_service_package()
+ # 2. read in all descriptor files
+ self._load_package_descriptor()
+ self._load_nsd()
+ self._load_vnfd()
+ if DEPLOY_SAP:
+ self._load_saps()
+ # 3. prepare container images (e.g. download or build Dockerfile)
+ if BUILD_DOCKERFILE:
+ self._load_docker_files()
+ self._build_images_from_dockerfiles()
+ else:
+ self._load_docker_urls()
+ self._pull_predefined_dockerimages()
+ LOG.info("On-boarded service: %r" % self.manifest.get("name"))
+
+ def start_service(self):
+ """
+ This methods creates and starts a new service instance.
+ It computes placements, iterates over all VNFDs, and starts
+ each VNFD as a Docker container in the data center selected
+ by the placement algorithm.
+ :return:
+ """
+ LOG.info("Starting service %r" % self.uuid)
+
+ # 1. each service instance gets a new uuid to identify it
+ instance_uuid = str(uuid.uuid4())
+ # build a instances dict (a bit like a NSR :))
+ self.instances[instance_uuid] = dict()
+ self.instances[instance_uuid]["vnf_instances"] = list()
+
+ # 2. Configure the chaining of the network functions (currently only E-Line and E-LAN links supported)
+ vnf_id2vnf_name = defaultdict(lambda: "NotExistingNode",
+ reduce(lambda x, y: dict(x, **y),
+ map(lambda d: {d["vnf_id"]: d["vnf_name"]},
+ self.nsd["network_functions"])))
+
+ # 3. compute placement of this service instance (adds DC names to VNFDs)
+ if not GK_STANDALONE_MODE:
+ #self._calculate_placement(FirstDcPlacement)
+ self._calculate_placement(RoundRobinDcPlacement)
+ # iterate over all vnfds that we have to start
+ for vnfd in self.vnfds.itervalues():
+ vnfi = None
+ if not GK_STANDALONE_MODE:
+ vnfi = self._start_vnfd(vnfd)
+ self.instances[instance_uuid]["vnf_instances"].append(vnfi)
+
+ vlinks = self.nsd["virtual_links"]
+ fwd_links = self.nsd["forwarding_graphs"][0]["constituent_virtual_links"]
+ eline_fwd_links = [l for l in vlinks if (l["id"] in fwd_links) and (l["connectivity_type"] == "E-Line")]
+ elan_fwd_links = [l for l in vlinks if (l["id"] in fwd_links) and (l["connectivity_type"] == "E-LAN")]
+
+ # 4a. deploy E-Line links
+ # cookie is used as identifier for the flowrules installed by the dummygatekeeper
+ # eg. different services get a unique cookie for their flowrules
+ cookie = 1
+ for link in eline_fwd_links:
+ src_id, src_if_name = link["connection_points_reference"][0].split(":")
+ dst_id, dst_if_name = link["connection_points_reference"][1].split(":")
+
+ # check if there is a SAP in the link
+ if src_id in self.sap_identifiers:
+ src_docker_name = "{0}_{1}".format(src_id, src_if_name)
+ src_id = src_docker_name
+ else:
+ src_docker_name = src_id
+
+ if dst_id in self.sap_identifiers:
+ dst_docker_name = "{0}_{1}".format(dst_id, dst_if_name)
+ dst_id = dst_docker_name
+ else:
+ dst_docker_name = dst_id
+
+ src_name = vnf_id2vnf_name[src_id]
+ dst_name = vnf_id2vnf_name[dst_id]
+
+ LOG.debug(
+ "Setting up E-Line link. %s(%s:%s) -> %s(%s:%s)" % (
+ src_name, src_id, src_if_name, dst_name, dst_id, dst_if_name))
+
+ if (src_name in self.vnfds) and (dst_name in self.vnfds):
+ network = self.vnfds[src_name].get("dc").net # there should be a cleaner way to find the DCNetwork
+ LOG.debug(src_docker_name)
+ ret = network.setChain(
+ src_docker_name, dst_docker_name,
+ vnf_src_interface=src_if_name, vnf_dst_interface=dst_if_name,
+ bidirectional=BIDIRECTIONAL_CHAIN, cmd="add-flow", cookie=cookie, priority=10)
+
+ # re-configure the VNFs IP assignment and ensure that a new subnet is used for each E-Link
+ src_vnfi = self._get_vnf_instance(instance_uuid, src_name)
+ if src_vnfi is not None:
+ self._vnf_reconfigure_network(src_vnfi, src_if_name, self.eline_subnets_src.pop(0))
+ dst_vnfi = self._get_vnf_instance(instance_uuid, dst_name)
+ if dst_vnfi is not None:
+ self._vnf_reconfigure_network(dst_vnfi, dst_if_name, self.eline_subnets_dst.pop(0))
+
+ # 4b. deploy E-LAN links
+ base = 10
+ for link in elan_fwd_links:
+ # generate lan ip address
+ ip = 1
+ for intf in link["connection_points_reference"]:
+ ip_address = generate_lan_string("10.0", base, subnet_size=24, ip=ip)
+ vnf_id, intf_name = intf.split(":")
+ if vnf_id in self.sap_identifiers:
+ src_docker_name = "{0}_{1}".format(vnf_id, intf_name)
+ vnf_id = src_docker_name
+ vnf_name = vnf_id2vnf_name[vnf_id]
+ LOG.debug(
+ "Setting up E-LAN link. %s(%s:%s) -> %s" % (
+ vnf_name, vnf_id, intf_name, ip_address))
+
+ if vnf_name in self.vnfds:
+ # re-configure the VNFs IP assignment and ensure that a new subnet is used for each E-LAN
+ # E-LAN relies on the learning switch capability of Ryu which has to be turned on in the topology
+ # (DCNetwork(controller=RemoteController, enable_learning=True)), so no explicit chaining is necessary.
+ vnfi = self._get_vnf_instance(instance_uuid, vnf_name)
+ if vnfi is not None:
+ self._vnf_reconfigure_network(vnfi, intf_name, ip_address)
+ # increase for the next ip address on this E-LAN
+ ip += 1
+ # increase the base ip address for the next E-LAN
+ base += 1
+
+ # 5. run the emulator specific entrypoint scripts in the VNFIs of this service instance
+ self._trigger_emulator_start_scripts_in_vnfis(self.instances[instance_uuid]["vnf_instances"])
+
+ LOG.info("Service started. Instance id: %r" % instance_uuid)
+ return instance_uuid
+
+ def _start_vnfd(self, vnfd):
+ """
+ Start a single VNFD of this service
+ :param vnfd: vnfd descriptor dict
+ :return:
+ """
+ # iterate over all deployment units within each VNFDs
+ for u in vnfd.get("virtual_deployment_units"):
+ # 1. get the name of the docker image to start and the assigned DC
+ vnf_name = vnfd.get("name")
+ if vnf_name not in self.remote_docker_image_urls:
+ raise Exception("No image name for %r found. Abort." % vnf_name)
+ docker_name = self.remote_docker_image_urls.get(vnf_name)
+ target_dc = vnfd.get("dc")
+ # 2. perform some checks to ensure we can start the container
+ assert(docker_name is not None)
+ assert(target_dc is not None)
+ if not self._check_docker_image_exists(docker_name):
+ raise Exception("Docker image %r not found. Abort." % docker_name)
+ # 3. do the dc.startCompute(name="foobar") call to run the container
+ # TODO consider flavors, and other annotations
+ intfs = vnfd.get("connection_points")
+
+ # TODO: get all vnf id's from the nsd for this vnfd and use those as dockername
+ # use the vnf_id in the nsd as docker name
+ # so deployed containers can be easily mapped back to the nsd
+ vnf_name2id = defaultdict(lambda: "NotExistingNode",
+ reduce(lambda x, y: dict(x, **y),
+ map(lambda d: {d["vnf_name"]: d["vnf_id"]},
+ self.nsd["network_functions"])))
+ self.vnf_name2docker_name[vnf_name] = vnf_name2id[vnf_name]
+ # self.vnf_name2docker_name[vnf_name] = GK.get_next_vnf_name()
+
+ LOG.info("Starting %r as %r in DC %r" % (vnf_name, self.vnf_name2docker_name[vnf_name], vnfd.get("dc")))
+ LOG.debug("Interfaces for %r: %r" % (vnf_name, intfs))
+ vnfi = target_dc.startCompute(self.vnf_name2docker_name[vnf_name], network=intfs, image=docker_name, flavor_name="small")
+ return vnfi
+
+ def _get_vnf_instance(self, instance_uuid, name):
+ """
+ Returns the Docker object for the given VNF name (or Docker name).
+ :param instance_uuid: UUID of the service instance to search in.
+ :param name: VNF name or Docker name. We are fuzzy here.
+ :return:
+ """
+ dn = name
+ if name in self.vnf_name2docker_name:
+ dn = self.vnf_name2docker_name[name]
+ for vnfi in self.instances[instance_uuid]["vnf_instances"]:
+ if vnfi.name == dn:
+ return vnfi
+ LOG.warning("No container with name: %r found.")
+ return None
+
+ @staticmethod
+ def _vnf_reconfigure_network(vnfi, if_name, net_str):
+ """
+ Reconfigure the network configuration of a specific interface
+ of a running container.
+ :param vnfi: container instacne
+ :param if_name: interface name
+ :param net_str: network configuration string, e.g., 1.2.3.4/24
+ :return:
+ """
+ intf = vnfi.intf(intf=if_name)
+ if intf is not None:
+ intf.setIP(net_str)
+ LOG.debug("Reconfigured network of %s:%s to %r" % (vnfi.name, if_name, net_str))
+ else:
+ LOG.warning("Interface not found: %s:%s. Network reconfiguration skipped." % (vnfi.name, if_name))
+
+
+ def _trigger_emulator_start_scripts_in_vnfis(self, vnfi_list):
+ for vnfi in vnfi_list:
+ config = vnfi.dcinfo.get("Config", dict())
+ env = config.get("Env", list())
+ for env_var in env:
+ if "SON_EMU_CMD=" in env_var:
+ cmd = str(env_var.split("=")[1])
+ LOG.info("Executing entry point script in %r: %r" % (vnfi.name, cmd))
+ # execute command in new thread to ensure that GK is not blocked by VNF
+ t = threading.Thread(target=vnfi.cmdPrint, args=(cmd,))
+ t.daemon = True
+ t.start()
+
+ def _unpack_service_package(self):
+ """
+ unzip *.son file and store contents in CATALOG_FOLDER/services/<service_uuid>/
+ """
+ LOG.info("Unzipping: %r" % self.package_file_path)
+ with zipfile.ZipFile(self.package_file_path, "r") as z:
+ z.extractall(self.package_content_path)
+
+
+ def _load_package_descriptor(self):
+ """
+ Load the main package descriptor YAML and keep it as dict.
+ :return:
+ """
+ self.manifest = load_yaml(
+ os.path.join(
+ self.package_content_path, "META-INF/MANIFEST.MF"))
+
+ def _load_nsd(self):
+ """
+ Load the entry NSD YAML and keep it as dict.
+ :return:
+ """
+ if "entry_service_template" in self.manifest:
+ nsd_path = os.path.join(
+ self.package_content_path,
+ make_relative_path(self.manifest.get("entry_service_template")))
+ self.nsd = load_yaml(nsd_path)
+ LOG.debug("Loaded NSD: %r" % self.nsd.get("name"))
+
+ def _load_vnfd(self):
+ """
+ Load all VNFD YAML files referenced in MANIFEST.MF and keep them in dict.
+ :return:
+ """
+ if "package_content" in self.manifest:
+ for pc in self.manifest.get("package_content"):
+ if pc.get("content-type") == "application/sonata.function_descriptor":
+ vnfd_path = os.path.join(
+ self.package_content_path,
+ make_relative_path(pc.get("name")))
+ vnfd = load_yaml(vnfd_path)
+ self.vnfds[vnfd.get("name")] = vnfd
+ LOG.debug("Loaded VNFD: %r" % vnfd.get("name"))
+
+ def _load_saps(self):
+ # Each Service Access Point (connection_point) in the nsd is getting its own container
+ SAPs = [p["id"] for p in self.nsd["connection_points"] if p["type"] == "interface"]
+ for sap in SAPs:
+ # endpoints needed in this service
+ sap_vnf_id, sap_vnf_interface = sap.split(':')
+ # set of the connection_point ids found in the nsd (in the examples this is 'ns')
+ self.sap_identifiers.add(sap_vnf_id)
+
+ sap_docker_name = "%s_%s" % (sap_vnf_id, sap_vnf_interface)
+
+ # add SAP to self.vnfds
+ sapfile = pkg_resources.resource_filename(__name__, "sap_vnfd.yml")
+ sap_vnfd = load_yaml(sapfile)
+ sap_vnfd["connection_points"][0]["id"] = sap_vnf_interface
+ sap_vnfd["name"] = sap_docker_name
+ self.vnfds[sap_docker_name] = sap_vnfd
+ # add SAP vnf to list in the NSD so it is deployed later on
+ # each SAP get a unique VNFD and vnf_id in the NSD
+ self.nsd["network_functions"].append({"vnf_id": sap_docker_name, "vnf_name": sap_docker_name})
+ LOG.debug("Loaded SAP: %r" % sap_vnfd.get("name"))
+
+ def _load_docker_files(self):
+ """
+ Get all paths to Dockerfiles from VNFDs and store them in dict.
+ :return:
+ """
+ for k, v in self.vnfds.iteritems():
+ for vu in v.get("virtual_deployment_units"):
+ if vu.get("vm_image_format") == "docker":
+ vm_image = vu.get("vm_image")
+ docker_path = os.path.join(
+ self.package_content_path,
+ make_relative_path(vm_image))
+ self.local_docker_files[k] = docker_path
+ LOG.debug("Found Dockerfile (%r): %r" % (k, docker_path))
+
+ def _load_docker_urls(self):
+ """
+ Get all URLs to pre-build docker images in some repo.
+ :return:
+ """
+ for k, v in self.vnfds.iteritems():
+ for vu in v.get("virtual_deployment_units"):
+ if vu.get("vm_image_format") == "docker":
+ url = vu.get("vm_image")
+ if url is not None:
+ url = url.replace("http://", "")
+ self.remote_docker_image_urls[k] = url
+ LOG.debug("Found Docker image URL (%r): %r" % (k, self.remote_docker_image_urls[k]))
+
+ def _build_images_from_dockerfiles(self):
+ """
+ Build Docker images for each local Dockerfile found in the package: self.local_docker_files
+ """
+ if GK_STANDALONE_MODE:
+ return # do not build anything in standalone mode
+ dc = DockerClient()
+ LOG.info("Building %d Docker images (this may take several minutes) ..." % len(self.local_docker_files))
+ for k, v in self.local_docker_files.iteritems():
+ for line in dc.build(path=v.replace("Dockerfile", ""), tag=k, rm=False, nocache=False):
+ LOG.debug("DOCKER BUILD: %s" % line)
+ LOG.info("Docker image created: %s" % k)
+
+ def _pull_predefined_dockerimages(self):
+ """
+ If the package contains URLs to pre-build Docker images, we download them with this method.
+ """
+ dc = DockerClient()
+ for url in self.remote_docker_image_urls.itervalues():
+ if not FORCE_PULL: # only pull if not present (speedup for development)
+ if len(dc.images(name=url)) > 0:
+ LOG.debug("Image %r present. Skipping pull." % url)
+ continue
+ LOG.info("Pulling image: %r" % url)
+ dc.pull(url,
+ insecure_registry=True)
+
+ def _check_docker_image_exists(self, image_name):
+ """
+ Query the docker service and check if the given image exists
+ :param image_name: name of the docker image
+ :return:
+ """
+ return len(DockerClient().images(image_name)) > 0
+
+ def _calculate_placement(self, algorithm):
+ """
+ Do placement by adding the a field "dc" to
+ each VNFD that points to one of our
+ data center objects known to the gatekeeper.
+ """
+ assert(len(self.vnfds) > 0)
+ assert(len(GK.dcs) > 0)
+ # instantiate algorithm an place
+ p = algorithm()
+ p.place(self.nsd, self.vnfds, GK.dcs)
+ LOG.info("Using placement algorithm: %r" % p.__class__.__name__)
+ # lets print the placement result
+ for name, vnfd in self.vnfds.iteritems():
+ LOG.info("Placed VNF %r on DC %r" % (name, str(vnfd.get("dc"))))
+
+
+"""
+Some (simple) placement algorithms
+"""
+
+
+class FirstDcPlacement(object):
+ """
+ Placement: Always use one and the same data center from the GK.dcs dict.
+ """
+ def place(self, nsd, vnfds, dcs):
+ for name, vnfd in vnfds.iteritems():
+ vnfd["dc"] = list(dcs.itervalues())[0]
+
+
+class RoundRobinDcPlacement(object):
+ """
+ Placement: Distribute VNFs across all available DCs in a round robin fashion.
+ """
+ def place(self, nsd, vnfds, dcs):
+ c = 0
+ dcs_list = list(dcs.itervalues())
+ for name, vnfd in vnfds.iteritems():
+ vnfd["dc"] = dcs_list[c % len(dcs_list)]
+ c += 1 # inc. c to use next DC
+
+
+
+
+"""
+Resource definitions and API endpoints
+"""
+
+
+class Packages(fr.Resource):
+
+ def post(self):
+ """
+ Upload a *.son service package to the dummy gatekeeper.
+
+ We expect request with a *.son file and store it in UPLOAD_FOLDER
+ :return: UUID
+ """
+ try:
+ # get file contents
+ print(request.files)
+ # lets search for the package in the request
+ if "package" in request.files:
+ son_file = request.files["package"]
+ # elif "file" in request.files:
+ # son_file = request.files["file"]
+ else:
+ return {"service_uuid": None, "size": 0, "sha1": None, "error": "upload failed. file not found."}, 500
+ # generate a uuid to reference this package
+ service_uuid = str(uuid.uuid4())
+ file_hash = hashlib.sha1(str(son_file)).hexdigest()
+ # ensure that upload folder exists
+ ensure_dir(UPLOAD_FOLDER)
+ upload_path = os.path.join(UPLOAD_FOLDER, "%s.son" % service_uuid)
+ # store *.son file to disk
+ son_file.save(upload_path)
+ size = os.path.getsize(upload_path)
+ # create a service object and register it
+ s = Service(service_uuid, file_hash, upload_path)
+ GK.register_service_package(service_uuid, s)
+ # generate the JSON result
+ return {"service_uuid": service_uuid, "size": size, "sha1": file_hash, "error": None}
+ except Exception as ex:
+ LOG.exception("Service package upload failed:")
+ return {"service_uuid": None, "size": 0, "sha1": None, "error": "upload failed"}, 500
+
+ def get(self):
+ """
+ Return a list of UUID's of uploaded service packages.
+ :return: dict/list
+ """
+ LOG.info("GET /packages")
+ return {"service_uuid_list": list(GK.services.iterkeys())}
+
+
+class Instantiations(fr.Resource):
+
+ def post(self):
+ """
+ Instantiate a service specified by its UUID.
+ Will return a new UUID to identify the running service instance.
+ :return: UUID
+ """
+ # try to extract the service uuid from the request
+ json_data = request.get_json(force=True)
+ service_uuid = json_data.get("service_uuid")
+
+ # lets be a bit fuzzy here to make testing easier
+ if service_uuid is None and len(GK.services) > 0:
+ # if we don't get a service uuid, we simple start the first service in the list
+ service_uuid = list(GK.services.iterkeys())[0]
+
+ if service_uuid in GK.services:
+ # ok, we have a service uuid, lets start the service
+ service_instance_uuid = GK.services.get(service_uuid).start_service()
+ return {"service_instance_uuid": service_instance_uuid}
+ return "Service not found", 404
+
+ def get(self):
+ """
+ Returns a list of UUIDs containing all running services.
+ :return: dict / list
+ """
+ LOG.info("GET /instantiations")
+ return {"service_instantiations_list": [
+ list(s.instances.iterkeys()) for s in GK.services.itervalues()]}
+
+
+# create a single, global GK object
+GK = Gatekeeper()
+# setup Flask
+app = Flask(__name__)
+app.config['MAX_CONTENT_LENGTH'] = 512 * 1024 * 1024 # 512 MB max upload
+api = fr.Api(app)
+# define endpoints
+api.add_resource(Packages, '/packages')
+api.add_resource(Instantiations, '/instantiations')
+
+
+def start_rest_api(host, port, datacenters=dict()):
+ GK.dcs = datacenters
+ # start the Flask server (not the best performance but ok for our use case)
+ app.run(host=host,
+ port=port,
+ debug=True,
+ use_reloader=False # this is needed to run Flask in a non-main thread
+ )
+
+
+def ensure_dir(name):
+ if not os.path.exists(name):
+ os.makedirs(name)
+
+
+def load_yaml(path):
+ with open(path, "r") as f:
+ try:
+ r = yaml.load(f)
+ except yaml.YAMLError as exc:
+ LOG.exception("YAML parse error")
+ r = dict()
+ return r
+
+
+def make_relative_path(path):
+ if path.startswith("file://"):
+ path = path.replace("file://", "", 1)
+ if path.startswith("/"):
+ path = path.replace("/", "", 1)
+ return path
+
+
+def generate_lan_string(prefix, base, subnet_size=24, ip=0):
+ """
+ Helper to generate different network configuration strings.
+ """
+ r = "%s.%d.%d/%d" % (prefix, base, ip, subnet_size)
+ return r
+
+
+def generate_subnet_strings(n, start=1, subnet_size=24, ip=0):
+ """
+ Helper to generate different network configuration strings.
+ """
+ r = list()
+ for i in range(start, start + n):
+ r.append("%d.0.0.%d/%d" % (i, ip, subnet_size))
+ return r
+
+
+if __name__ == '__main__':
+ """
+ Lets allow to run the API in standalone mode.
+ """
+ GK_STANDALONE_MODE = True
+ logging.getLogger("werkzeug").setLevel(logging.INFO)
+ start_rest_api("0.0.0.0", 8000)
+