src/emuvim/api/sonata/dummygatekeeper.py

   1 """
   2 Copyright (c) 2015 SONATA-NFV and Paderborn University
   3 ALL RIGHTS RESERVED.
   4
   5 Licensed under the Apache License, Version 2.0 (the "License");
   6 you may not use this file except in compliance with the License.
   7 You may obtain a copy of the License at
   8
   9     http://www.apache.org/licenses/LICENSE-2.0
  10
  11 Unless required by applicable law or agreed to in writing, software
  12 distributed under the License is distributed on an "AS IS" BASIS,
  13 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 See the License for the specific language governing permissions and
  15 limitations under the License.
  16
  17 Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
  18 nor the names of its contributors may be used to endorse or promote
  19 products derived from this software without specific prior written
  20 permission.
  21
  22 This work has been performed in the framework of the SONATA project,
  23 funded by the European Commission under Grant number 671517 through
  24 the Horizon 2020 and 5G-PPP programmes. The authors would like to
  25 acknowledge the contributions of their colleagues of the SONATA
  26 partner consortium (www.sonata-nfv.eu).
  27 """
  28 """
  29 This module implements a simple REST API that behaves like SONATA's gatekeeper.
  30
  31 It is only used to support the development of SONATA's SDK tools and to demonstrate
  32 the year 1 version of the emulator until the integration with WP4's orchestrator is done.
  33 """
  34
  35 import logging
  36 import os
  37 import uuid
  38 import hashlib
  39 import zipfile
  40 import yaml
  41 import threading
  42 from docker import Client as DockerClient
  43 from flask import Flask, request
  44 import flask_restful as fr
  45 from collections import defaultdict
  46 import pkg_resources
  47
  48 logging.basicConfig()
  49 LOG = logging.getLogger("sonata-dummy-gatekeeper")
  50 LOG.setLevel(logging.DEBUG)
  51 logging.getLogger("werkzeug").setLevel(logging.WARNING)
  52
  53 GK_STORAGE = "/tmp/son-dummy-gk/"
  54 UPLOAD_FOLDER = os.path.join(GK_STORAGE, "uploads/")
  55 CATALOG_FOLDER = os.path.join(GK_STORAGE, "catalog/")
  56
  57 # Enable Dockerfile build functionality
  58 BUILD_DOCKERFILE = False
  59
  60 # flag to indicate that we run without the emulator (only the bare API for integration testing)
  61 GK_STANDALONE_MODE = False
  62
  63 # should a new version of an image be pulled even if its available
  64 FORCE_PULL = False
  65
  66 # Automatically deploy SAPs (endpoints) of the service as new containers
  67 # Attention: This is not a configuration switch but a global variable! Don't change its default value.
  68 DEPLOY_SAP = False
  69
  70 # flag to indicate if we use bidirectional forwarding rules in the automatic chaining process
  71 BIDIRECTIONAL_CHAIN = False
  72
  73 class Gatekeeper(object):
  74
  75     def __init__(self):
  76         self.services = dict()
  77         self.dcs = dict()
  78         self.vnf_counter = 0  # used to generate short names for VNFs (Mininet limitation)
  79         LOG.info("Create SONATA dummy gatekeeper.")
  80
  81     def register_service_package(self, service_uuid, service):
  82         """
  83         register new service package
  84         :param service_uuid
  85         :param service object
  86         """
  87         self.services[service_uuid] = service
  88         # lets perform all steps needed to onboard the service
  89         service.onboard()
  90
  91     def get_next_vnf_name(self):
  92         self.vnf_counter += 1
  93         return "vnf%d" % self.vnf_counter
  94
  95
  96 class Service(object):
  97     """
  98     This class represents a NS uploaded as a *.son package to the
  99     dummy gatekeeper.
 100     Can have multiple running instances of this service.
 101     """
 102
 103     def __init__(self,
 104                  service_uuid,
 105                  package_file_hash,
 106                  package_file_path):
 107         self.uuid = service_uuid
 108         self.package_file_hash = package_file_hash
 109         self.package_file_path = package_file_path
 110         self.package_content_path = os.path.join(CATALOG_FOLDER, "services/%s" % self.uuid)
 111         self.manifest = None
 112         self.nsd = None
 113         self.vnfds = dict()
 114         self.local_docker_files = dict()
 115         self.remote_docker_image_urls = dict()
 116         self.instances = dict()
 117         self.vnf_name2docker_name = dict()
 118         self.sap_identifiers = set()
 119         # lets generate a set of subnet configurations used for e-line chaining setup
 120         self.eline_subnets_src = generate_subnet_strings(50, start=200, subnet_size=24, ip=1)
 121         self.eline_subnets_dst = generate_subnet_strings(50, start=200, subnet_size=24, ip=2)
 122
 123     def onboard(self):
 124         """
 125         Do all steps to prepare this service to be instantiated
 126         :return:
 127         """
 128         # 1. extract the contents of the package and store them in our catalog
 129         self._unpack_service_package()
 130         # 2. read in all descriptor files
 131         self._load_package_descriptor()
 132         self._load_nsd()
 133         self._load_vnfd()
 134         if DEPLOY_SAP:
 135             self._load_saps()
 136         # 3. prepare container images (e.g. download or build Dockerfile)
 137         if BUILD_DOCKERFILE:
 138             self._load_docker_files()
 139             self._build_images_from_dockerfiles()
 140         else:
 141             self._load_docker_urls()
 142             self._pull_predefined_dockerimages()
 143         LOG.info("On-boarded service: %r" % self.manifest.get("name"))
 144
 145     def start_service(self):
 146         """
 147         This methods creates and starts a new service instance.
 148         It computes placements, iterates over all VNFDs, and starts
 149         each VNFD as a Docker container in the data center selected
 150         by the placement algorithm.
 151         :return:
 152         """
 153         LOG.info("Starting service %r" % self.uuid)
 154
 155         # 1. each service instance gets a new uuid to identify it
 156         instance_uuid = str(uuid.uuid4())
 157         # build a instances dict (a bit like a NSR :))
 158         self.instances[instance_uuid] = dict()
 159         self.instances[instance_uuid]["vnf_instances"] = list()
 160
 161         # 2. Configure the chaining of the network functions (currently only E-Line and E-LAN links supported)
 162         vnf_id2vnf_name = defaultdict(lambda: "NotExistingNode",
 163                                       reduce(lambda x, y: dict(x, **y),
 164                                              map(lambda d: {d["vnf_id"]: d["vnf_name"]},
 165                                                  self.nsd["network_functions"])))
 166
 167         # 3. compute placement of this service instance (adds DC names to VNFDs)
 168         if not GK_STANDALONE_MODE:
 169             #self._calculate_placement(FirstDcPlacement)
 170             self._calculate_placement(RoundRobinDcPlacement)
 171         # iterate over all vnfds that we have to start
 172         for vnfd in self.vnfds.itervalues():
 173             vnfi = None
 174             if not GK_STANDALONE_MODE:
 175                 vnfi = self._start_vnfd(vnfd)
 176             self.instances[instance_uuid]["vnf_instances"].append(vnfi)
 177
 178         vlinks = self.nsd["virtual_links"]
 179         fwd_links = self.nsd["forwarding_graphs"][0]["constituent_virtual_links"]
 180         eline_fwd_links = [l for l in vlinks if (l["id"] in fwd_links) and (l["connectivity_type"] == "E-Line")]
 181         elan_fwd_links = [l for l in vlinks if (l["id"] in fwd_links) and (l["connectivity_type"] == "E-LAN")]
 182
 183         # 4a. deploy E-Line links
 184         # cookie is used as identifier for the flowrules installed by the dummygatekeeper
 185         # eg. different services get a unique cookie for their flowrules
 186         cookie = 1
 187         for link in eline_fwd_links:
 188             src_id, src_if_name = link["connection_points_reference"][0].split(":")
 189             dst_id, dst_if_name = link["connection_points_reference"][1].split(":")
 190
 191             # check if there is a SAP in the link
 192             if src_id in self.sap_identifiers:
 193                 src_docker_name = "{0}_{1}".format(src_id, src_if_name)
 194                 src_id = src_docker_name
 195             else:
 196                 src_docker_name = src_id
 197
 198             if dst_id in self.sap_identifiers:
 199                 dst_docker_name = "{0}_{1}".format(dst_id, dst_if_name)
 200                 dst_id = dst_docker_name
 201             else:
 202                 dst_docker_name = dst_id
 203
 204             src_name = vnf_id2vnf_name[src_id]
 205             dst_name = vnf_id2vnf_name[dst_id]
 206
 207             LOG.debug(
 208                 "Setting up E-Line link. %s(%s:%s) -> %s(%s:%s)" % (
 209                     src_name, src_id, src_if_name, dst_name, dst_id, dst_if_name))
 210
 211             if (src_name in self.vnfds) and (dst_name in self.vnfds):
 212                 network = self.vnfds[src_name].get("dc").net  # there should be a cleaner way to find the DCNetwork
 213                 LOG.debug(src_docker_name)
 214                 ret = network.setChain(
 215                     src_docker_name, dst_docker_name,
 216                     vnf_src_interface=src_if_name, vnf_dst_interface=dst_if_name,
 217                     bidirectional=BIDIRECTIONAL_CHAIN, cmd="add-flow", cookie=cookie, priority=10)
 218
 219                 # re-configure the VNFs IP assignment and ensure that a new subnet is used for each E-Link
 220                 src_vnfi = self._get_vnf_instance(instance_uuid, src_name)
 221                 if src_vnfi is not None:
 222                     self._vnf_reconfigure_network(src_vnfi, src_if_name, self.eline_subnets_src.pop(0))
 223                 dst_vnfi = self._get_vnf_instance(instance_uuid, dst_name)
 224                 if dst_vnfi is not None:
 225                     self._vnf_reconfigure_network(dst_vnfi, dst_if_name, self.eline_subnets_dst.pop(0))
 226
 227         # 4b. deploy E-LAN links
 228         base = 10
 229         for link in elan_fwd_links:
 230             # generate lan ip address
 231             ip = 1
 232             for intf in link["connection_points_reference"]:
 233                 ip_address = generate_lan_string("10.0", base, subnet_size=24, ip=ip)
 234                 vnf_id, intf_name = intf.split(":")
 235                 if vnf_id in self.sap_identifiers:
 236                     src_docker_name = "{0}_{1}".format(vnf_id, intf_name)
 237                     vnf_id = src_docker_name
 238                 vnf_name = vnf_id2vnf_name[vnf_id]
 239                 LOG.debug(
 240                     "Setting up E-LAN link. %s(%s:%s) -> %s" % (
 241                         vnf_name, vnf_id, intf_name, ip_address))
 242
 243                 if vnf_name in self.vnfds:
 244                     # re-configure the VNFs IP assignment and ensure that a new subnet is used for each E-LAN
 245                     # E-LAN relies on the learning switch capability of Ryu which has to be turned on in the topology
 246                     # (DCNetwork(controller=RemoteController, enable_learning=True)), so no explicit chaining is necessary.
 247                     vnfi = self._get_vnf_instance(instance_uuid, vnf_name)
 248                     if vnfi is not None:
 249                         self._vnf_reconfigure_network(vnfi, intf_name, ip_address)
 250                         # increase for the next ip address on this E-LAN
 251                         ip += 1
 252             # increase the base ip address for the next E-LAN
 253             base += 1
 254
 255         # 5. run the emulator specific entrypoint scripts in the VNFIs of this service instance
 256         self._trigger_emulator_start_scripts_in_vnfis(self.instances[instance_uuid]["vnf_instances"])
 257
 258         LOG.info("Service started. Instance id: %r" % instance_uuid)
 259         return instance_uuid
 260
 261     def _start_vnfd(self, vnfd):
 262         """
 263         Start a single VNFD of this service
 264         :param vnfd: vnfd descriptor dict
 265         :return:
 266         """
 267         # iterate over all deployment units within each VNFDs
 268         for u in vnfd.get("virtual_deployment_units"):
 269             # 1. get the name of the docker image to start and the assigned DC
 270             vnf_name = vnfd.get("name")
 271             if vnf_name not in self.remote_docker_image_urls:
 272                 raise Exception("No image name for %r found. Abort." % vnf_name)
 273             docker_name = self.remote_docker_image_urls.get(vnf_name)
 274             target_dc = vnfd.get("dc")
 275             # 2. perform some checks to ensure we can start the container
 276             assert(docker_name is not None)
 277             assert(target_dc is not None)
 278             if not self._check_docker_image_exists(docker_name):
 279                 raise Exception("Docker image %r not found. Abort." % docker_name)
 280             # 3. do the dc.startCompute(name="foobar") call to run the container
 281             # TODO consider flavors, and other annotations
 282             intfs = vnfd.get("connection_points")
 283
 284             # TODO: get all vnf id's from the nsd for this vnfd and use those as dockername
 285             # use the vnf_id in the nsd as docker name
 286             # so deployed containers can be easily mapped back to the nsd
 287             vnf_name2id = defaultdict(lambda: "NotExistingNode",
 288                                           reduce(lambda x, y: dict(x, **y),
 289                                                  map(lambda d: {d["vnf_name"]: d["vnf_id"]},
 290                                                      self.nsd["network_functions"])))
 291             self.vnf_name2docker_name[vnf_name] = vnf_name2id[vnf_name]
 292             # self.vnf_name2docker_name[vnf_name] = GK.get_next_vnf_name()
 293
 294             LOG.info("Starting %r as %r in DC %r" % (vnf_name, self.vnf_name2docker_name[vnf_name], vnfd.get("dc")))
 295             LOG.debug("Interfaces for %r: %r" % (vnf_name, intfs))
 296             vnfi = target_dc.startCompute(self.vnf_name2docker_name[vnf_name], network=intfs, image=docker_name, flavor_name="small")
 297             return vnfi
 298
 299     def _get_vnf_instance(self, instance_uuid, name):
 300         """
 301         Returns the Docker object for the given VNF name (or Docker name).
 302         :param instance_uuid: UUID of the service instance to search in.
 303         :param name: VNF name or Docker name. We are fuzzy here.
 304         :return:
 305         """
 306         dn = name
 307         if name in self.vnf_name2docker_name:
 308             dn = self.vnf_name2docker_name[name]
 309         for vnfi in self.instances[instance_uuid]["vnf_instances"]:
 310             if vnfi.name == dn:
 311                 return vnfi
 312         LOG.warning("No container with name: %r found.")
 313         return None
 314
 315     @staticmethod
 316     def _vnf_reconfigure_network(vnfi, if_name, net_str):
 317         """
 318         Reconfigure the network configuration of a specific interface
 319         of a running container.
 320         :param vnfi: container instacne
 321         :param if_name: interface name
 322         :param net_str: network configuration string, e.g., 1.2.3.4/24
 323         :return:
 324         """
 325         intf = vnfi.intf(intf=if_name)
 326         if intf is not None:
 327             intf.setIP(net_str)
 328             LOG.debug("Reconfigured network of %s:%s to %r" % (vnfi.name, if_name, net_str))
 329         else:
 330             LOG.warning("Interface not found: %s:%s. Network reconfiguration skipped." % (vnfi.name, if_name))
 331
 332
 333     def _trigger_emulator_start_scripts_in_vnfis(self, vnfi_list):
 334         for vnfi in vnfi_list:
 335             config = vnfi.dcinfo.get("Config", dict())
 336             env = config.get("Env", list())
 337             for env_var in env:
 338                 if "SON_EMU_CMD=" in env_var:
 339                     cmd = str(env_var.split("=")[1])
 340                     LOG.info("Executing entry point script in %r: %r" % (vnfi.name, cmd))
 341                     # execute command in new thread to ensure that GK is not blocked by VNF
 342                     t = threading.Thread(target=vnfi.cmdPrint, args=(cmd,))
 343                     t.daemon = True
 344                     t.start()
 345
 346     def _unpack_service_package(self):
 347         """
 348         unzip *.son file and store contents in CATALOG_FOLDER/services/<service_uuid>/
 349         """
 350         LOG.info("Unzipping: %r" % self.package_file_path)
 351         with zipfile.ZipFile(self.package_file_path, "r") as z:
 352             z.extractall(self.package_content_path)
 353
 354
 355     def _load_package_descriptor(self):
 356         """
 357         Load the main package descriptor YAML and keep it as dict.
 358         :return:
 359         """
 360         self.manifest = load_yaml(
 361             os.path.join(
 362                 self.package_content_path, "META-INF/MANIFEST.MF"))
 363
 364     def _load_nsd(self):
 365         """
 366         Load the entry NSD YAML and keep it as dict.
 367         :return:
 368         """
 369         if "entry_service_template" in self.manifest:
 370             nsd_path = os.path.join(
 371                 self.package_content_path,
 372                 make_relative_path(self.manifest.get("entry_service_template")))
 373             self.nsd = load_yaml(nsd_path)
 374             LOG.debug("Loaded NSD: %r" % self.nsd.get("name"))
 375
 376     def _load_vnfd(self):
 377         """
 378         Load all VNFD YAML files referenced in MANIFEST.MF and keep them in dict.
 379         :return:
 380         """
 381         if "package_content" in self.manifest:
 382             for pc in self.manifest.get("package_content"):
 383                 if pc.get("content-type") == "application/sonata.function_descriptor":
 384                     vnfd_path = os.path.join(
 385                         self.package_content_path,
 386                         make_relative_path(pc.get("name")))
 387                     vnfd = load_yaml(vnfd_path)
 388                     self.vnfds[vnfd.get("name")] = vnfd
 389                     LOG.debug("Loaded VNFD: %r" % vnfd.get("name"))
 390
 391     def _load_saps(self):
 392         # Each Service Access Point (connection_point) in the nsd is getting its own container
 393         SAPs = [p["id"] for p in self.nsd["connection_points"] if p["type"] == "interface"]
 394         for sap in SAPs:
 395             # endpoints needed in this service
 396             sap_vnf_id, sap_vnf_interface = sap.split(':')
 397             # set of the connection_point ids found in the nsd (in the examples this is 'ns')
 398             self.sap_identifiers.add(sap_vnf_id)
 399
 400             sap_docker_name = "%s_%s" % (sap_vnf_id, sap_vnf_interface)
 401
 402             # add SAP to self.vnfds
 403             sapfile = pkg_resources.resource_filename(__name__, "sap_vnfd.yml")
 404             sap_vnfd = load_yaml(sapfile)
 405             sap_vnfd["connection_points"][0]["id"] = sap_vnf_interface
 406             sap_vnfd["name"] = sap_docker_name
 407             self.vnfds[sap_docker_name] = sap_vnfd
 408             # add SAP vnf to list in the NSD so it is deployed later on
 409             # each SAP get a unique VNFD and vnf_id in the NSD
 410             self.nsd["network_functions"].append({"vnf_id": sap_docker_name, "vnf_name": sap_docker_name})
 411             LOG.debug("Loaded SAP: %r" % sap_vnfd.get("name"))
 412
 413     def _load_docker_files(self):
 414         """
 415         Get all paths to Dockerfiles from VNFDs and store them in dict.
 416         :return:
 417         """
 418         for k, v in self.vnfds.iteritems():
 419             for vu in v.get("virtual_deployment_units"):
 420                 if vu.get("vm_image_format") == "docker":
 421                     vm_image = vu.get("vm_image")
 422                     docker_path = os.path.join(
 423                         self.package_content_path,
 424                         make_relative_path(vm_image))
 425                     self.local_docker_files[k] = docker_path
 426                     LOG.debug("Found Dockerfile (%r): %r" % (k, docker_path))
 427
 428     def _load_docker_urls(self):
 429         """
 430         Get all URLs to pre-build docker images in some repo.
 431         :return:
 432         """
 433         for k, v in self.vnfds.iteritems():
 434             for vu in v.get("virtual_deployment_units"):
 435                 if vu.get("vm_image_format") == "docker":
 436                     url = vu.get("vm_image")
 437                     if url is not None:
 438                         url = url.replace("http://", "")
 439                         self.remote_docker_image_urls[k] = url
 440                         LOG.debug("Found Docker image URL (%r): %r" % (k, self.remote_docker_image_urls[k]))
 441
 442     def _build_images_from_dockerfiles(self):
 443         """
 444         Build Docker images for each local Dockerfile found in the package: self.local_docker_files
 445         """
 446         if GK_STANDALONE_MODE:
 447             return  # do not build anything in standalone mode
 448         dc = DockerClient()
 449         LOG.info("Building %d Docker images (this may take several minutes) ..." % len(self.local_docker_files))
 450         for k, v in self.local_docker_files.iteritems():
 451             for line in dc.build(path=v.replace("Dockerfile", ""), tag=k, rm=False, nocache=False):
 452                 LOG.debug("DOCKER BUILD: %s" % line)
 453             LOG.info("Docker image created: %s" % k)
 454
 455     def _pull_predefined_dockerimages(self):
 456         """
 457         If the package contains URLs to pre-build Docker images, we download them with this method.
 458         """
 459         dc = DockerClient()
 460         for url in self.remote_docker_image_urls.itervalues():
 461             if not FORCE_PULL:  # only pull if not present (speedup for development)
 462                 if len(dc.images(name=url)) > 0:
 463                     LOG.debug("Image %r present. Skipping pull." % url)
 464                     continue
 465             LOG.info("Pulling image: %r" % url)
 466             dc.pull(url,
 467                     insecure_registry=True)
 468
 469     def _check_docker_image_exists(self, image_name):
 470         """
 471         Query the docker service and check if the given image exists
 472         :param image_name: name of the docker image
 473         :return:
 474         """
 475         return len(DockerClient().images(image_name)) > 0
 476
 477     def _calculate_placement(self, algorithm):
 478         """
 479         Do placement by adding the a field "dc" to
 480         each VNFD that points to one of our
 481         data center objects known to the gatekeeper.
 482         """
 483         assert(len(self.vnfds) > 0)
 484         assert(len(GK.dcs) > 0)
 485         # instantiate algorithm an place
 486         p = algorithm()
 487         p.place(self.nsd, self.vnfds, GK.dcs)
 488         LOG.info("Using placement algorithm: %r" % p.__class__.__name__)
 489         # lets print the placement result
 490         for name, vnfd in self.vnfds.iteritems():
 491             LOG.info("Placed VNF %r on DC %r" % (name, str(vnfd.get("dc"))))
 492
 493
 494 """
 495 Some (simple) placement algorithms
 496 """
 497
 498
 499 class FirstDcPlacement(object):
 500     """
 501     Placement: Always use one and the same data center from the GK.dcs dict.
 502     """
 503     def place(self, nsd, vnfds, dcs):
 504         for name, vnfd in vnfds.iteritems():
 505             vnfd["dc"] = list(dcs.itervalues())[0]
 506
 507
 508 class RoundRobinDcPlacement(object):
 509     """
 510     Placement: Distribute VNFs across all available DCs in a round robin fashion.
 511     """
 512     def place(self, nsd, vnfds, dcs):
 513         c = 0
 514         dcs_list = list(dcs.itervalues())
 515         for name, vnfd in vnfds.iteritems():
 516             vnfd["dc"] = dcs_list[c % len(dcs_list)]
 517             c += 1  # inc. c to use next DC
 518
 519
 520
 521
 522 """
 523 Resource definitions and API endpoints
 524 """
 525
 526
 527 class Packages(fr.Resource):
 528
 529     def post(self):
 530         """
 531         Upload a *.son service package to the dummy gatekeeper.
 532
 533         We expect request with a *.son file and store it in UPLOAD_FOLDER
 534         :return: UUID
 535         """
 536         try:
 537             # get file contents
 538             print(request.files)
 539             # lets search for the package in the request
 540             if "package" in request.files:
 541                 son_file = request.files["package"]
 542             # elif "file" in request.files:
 543             #     son_file = request.files["file"]
 544             else:
 545                 return {"service_uuid": None, "size": 0, "sha1": None, "error": "upload failed. file not found."}, 500
 546             # generate a uuid to reference this package
 547             service_uuid = str(uuid.uuid4())
 548             file_hash = hashlib.sha1(str(son_file)).hexdigest()
 549             # ensure that upload folder exists
 550             ensure_dir(UPLOAD_FOLDER)
 551             upload_path = os.path.join(UPLOAD_FOLDER, "%s.son" % service_uuid)
 552             # store *.son file to disk
 553             son_file.save(upload_path)
 554             size = os.path.getsize(upload_path)
 555             # create a service object and register it
 556             s = Service(service_uuid, file_hash, upload_path)
 557             GK.register_service_package(service_uuid, s)
 558             # generate the JSON result
 559             return {"service_uuid": service_uuid, "size": size, "sha1": file_hash, "error": None}, 201
 560         except Exception as ex:
 561             LOG.exception("Service package upload failed:")
 562             return {"service_uuid": None, "size": 0, "sha1": None, "error": "upload failed"}, 500
 563
 564     def get(self):
 565         """
 566         Return a list of UUID's of uploaded service packages.
 567         :return: dict/list
 568         """
 569         LOG.info("GET /packages")
 570         return {"service_uuid_list": list(GK.services.iterkeys())}
 571
 572
 573 class Instantiations(fr.Resource):
 574
 575     def post(self):
 576         """
 577         Instantiate a service specified by its UUID.
 578         Will return a new UUID to identify the running service instance.
 579         :return: UUID
 580         """
 581         # try to extract the service uuid from the request
 582         json_data = request.get_json(force=True)
 583         service_uuid = json_data.get("service_uuid")
 584
 585         # lets be a bit fuzzy here to make testing easier
 586         if service_uuid is None and len(GK.services) > 0:
 587             # if we don't get a service uuid, we simple start the first service in the list
 588             service_uuid = list(GK.services.iterkeys())[0]
 589
 590         if service_uuid in GK.services:
 591             # ok, we have a service uuid, lets start the service
 592             service_instance_uuid = GK.services.get(service_uuid).start_service()
 593             return {"service_instance_uuid": service_instance_uuid}
 594         return "Service not found", 404
 595
 596     def get(self):
 597         """
 598         Returns a list of UUIDs containing all running services.
 599         :return: dict / list
 600         """
 601         LOG.info("GET /instantiations")
 602         return {"service_instantiations_list": [
 603             list(s.instances.iterkeys()) for s in GK.services.itervalues()]}
 604
 605
 606 # create a single, global GK object
 607 GK = Gatekeeper()
 608 # setup Flask
 609 app = Flask(__name__)
 610 app.config['MAX_CONTENT_LENGTH'] = 512 * 1024 * 1024  # 512 MB max upload
 611 api = fr.Api(app)
 612 # define endpoints
 613 api.add_resource(Packages, '/packages')
 614 api.add_resource(Instantiations, '/instantiations')
 615
 616
 617 def start_rest_api(host, port, datacenters=dict()):
 618     GK.dcs = datacenters
 619     # start the Flask server (not the best performance but ok for our use case)
 620     app.run(host=host,
 621             port=port,
 622             debug=True,
 623             use_reloader=False  # this is needed to run Flask in a non-main thread
 624             )
 625
 626
 627 def ensure_dir(name):
 628     if not os.path.exists(name):
 629         os.makedirs(name)
 630
 631
 632 def load_yaml(path):
 633     with open(path, "r") as f:
 634         try:
 635             r = yaml.load(f)
 636         except yaml.YAMLError as exc:
 637             LOG.exception("YAML parse error")
 638             r = dict()
 639     return r
 640
 641
 642 def make_relative_path(path):
 643     if path.startswith("file://"):
 644         path = path.replace("file://", "", 1)
 645     if path.startswith("/"):
 646         path = path.replace("/", "", 1)
 647     return path
 648
 649
 650 def generate_lan_string(prefix, base, subnet_size=24, ip=0):
 651     """
 652     Helper to generate different network configuration strings.
 653     """
 654     r = "%s.%d.%d/%d" % (prefix, base, ip, subnet_size)
 655     return r
 656
 657
 658 def generate_subnet_strings(n, start=1, subnet_size=24, ip=0):
 659     """
 660     Helper to generate different network configuration strings.
 661     """
 662     r = list()
 663     for i in range(start, start + n):
 664         r.append("%d.0.0.%d/%d" % (i, ip, subnet_size))
 665     return r
 666
 667
 668 if __name__ == '__main__':
 669     """
 670     Lets allow to run the API in standalone mode.
 671     """
 672     GK_STANDALONE_MODE = True
 673     logging.getLogger("werkzeug").setLevel(logging.INFO)
 674     start_rest_api("0.0.0.0", 8000)
 675