src/emuvim/api/sonata/dummygatekeeper.py

   1 """
   2 This module implements a simple REST API that behaves like SONATA's gatekeeper.
   3
   4 It is only used to support the development of SONATA's SDK tools and to demonstrate
   5 the year 1 version of the emulator until the integration with WP4's orchestrator is done.
   6 """
   7
   8 import logging
   9 import os
  10 import uuid
  11 import hashlib
  12 import zipfile
  13 import yaml
  14 from docker import Client as DockerClient
  15 from flask import Flask, request
  16 import flask_restful as fr
  17
  18 logging.basicConfig()
  19 LOG = logging.getLogger("sonata-dummy-gatekeeper")
  20 LOG.setLevel(logging.DEBUG)
  21 logging.getLogger("werkzeug").setLevel(logging.WARNING)
  22
  23 GK_STORAGE = "/tmp/son-dummy-gk/"
  24 UPLOAD_FOLDER = os.path.join(GK_STORAGE, "uploads/")
  25 CATALOG_FOLDER = os.path.join(GK_STORAGE, "catalog/")
  26
  27 # flag to indicate that we run without the emulator (only the bare API for integration testing)
  28 GK_STANDALONE_MODE = False
  29
  30
  31 class Gatekeeper(object):
  32
  33     def __init__(self):
  34         self.services = dict()
  35         self.dcs = dict()
  36         self.vnf_counter = 0  # used to generate short names for VNFs (Mininet limitation)
  37         LOG.info("Create SONATA dummy gatekeeper.")
  38
  39     def register_service_package(self, service_uuid, service):
  40         """
  41         register new service package
  42         :param service_uuid
  43         :param service object
  44         """
  45         self.services[service_uuid] = service
  46         # lets perform all steps needed to onboard the service
  47         service.onboard()
  48
  49     def get_next_vnf_name(self):
  50         self.vnf_counter += 1
  51         return "vnf%d" % self.vnf_counter
  52
  53
  54 class Service(object):
  55     """
  56     This class represents a NS uploaded as a *.son package to the
  57     dummy gatekeeper.
  58     Can have multiple running instances of this service.
  59     """
  60
  61     def __init__(self,
  62                  service_uuid,
  63                  package_file_hash,
  64                  package_file_path):
  65         self.uuid = service_uuid
  66         self.package_file_hash = package_file_hash
  67         self.package_file_path = package_file_path
  68         self.package_content_path = os.path.join(CATALOG_FOLDER, "services/%s" % self.uuid)
  69         self.manifest = None
  70         self.nsd = None
  71         self.vnfds = dict()
  72         self.local_docker_files = dict()
  73         self.instances = dict()
  74
  75     def onboard(self):
  76         """
  77         Do all steps to prepare this service to be instantiated
  78         :return:
  79         """
  80         # 1. extract the contents of the package and store them in our catalog
  81         self._unpack_service_package()
  82         # 2. read in all descriptor files
  83         self._load_package_descriptor()
  84         self._load_nsd()
  85         self._load_vnfd()
  86         self._load_docker_files()
  87         # 3. prepare container images (e.g. download or build Dockerfile)
  88         self._build_images_from_dockerfiles()
  89         self._download_predefined_dockerimages()
  90
  91         LOG.info("On-boarded service: %r" % self.manifest.get("package_name"))
  92
  93     def start_service(self):
  94         """
  95         This methods creates and starts a new service instance.
  96         It computes placements, iterates over all VNFDs, and starts
  97         each VNFD as a Docker container in the data center selected
  98         by the placement algorithm.
  99         :return:
 100         """
 101         LOG.info("Starting service %r" % self.uuid)
 102         # 1. each service instance gets a new uuid to identify it
 103         instance_uuid = str(uuid.uuid4())
 104         # build a instances dict (a bit like a NSR :))
 105         self.instances[instance_uuid] = dict()
 106         self.instances[instance_uuid]["vnf_instances"] = list()
 107         # 2. compute placement of this service instance (adds DC names to VNFDs)
 108         if not GK_STANDALONE_MODE:
 109             self._calculate_placement(FirstDcPlacement)
 110         # iterate over all vnfds that we have to start
 111         for vnfd in self.vnfds.itervalues():
 112             vnfi = None
 113             if not GK_STANDALONE_MODE:
 114                 vnfi = self._start_vnfd(vnfd)
 115             self.instances[instance_uuid]["vnf_instances"].append(vnfi)
 116         LOG.info("Service started. Instance id: %r" % instance_uuid)
 117         return instance_uuid
 118
 119     def _start_vnfd(self, vnfd):
 120         """
 121         Start a single VNFD of this service
 122         :param vnfd: vnfd descriptor dict
 123         :return:
 124         """
 125         # iterate over all deployment units within each VNFDs
 126         for u in vnfd.get("virtual_deployment_units"):
 127             # 1. get the name of the docker image to start and the assigned DC
 128             docker_name = vnfd.get("vnf_name")
 129             target_dc = vnfd.get("dc")
 130             # 2. perform some checks to ensure we can start the container
 131             assert(docker_name is not None)
 132             assert(target_dc is not None)
 133             if not self._check_docker_image_exists(docker_name):
 134                 raise Exception("Docker image %r not found. Abort." % docker_name)
 135             # 3. do the dc.startCompute(name="foobar") call to run the container
 136             # TODO consider flavors, and other annotations
 137             vnfi = target_dc.startCompute(GK.get_next_vnf_name(), image=docker_name, flavor_name="small")
 138             # 6. store references to the compute objects in self.instances
 139             return vnfi
 140
 141     def _unpack_service_package(self):
 142         """
 143         unzip *.son file and store contents in CATALOG_FOLDER/services/<service_uuid>/
 144         """
 145         with zipfile.ZipFile(self.package_file_path, "r") as z:
 146             z.extractall(self.package_content_path)
 147
 148     def _load_package_descriptor(self):
 149         """
 150         Load the main package descriptor YAML and keep it as dict.
 151         :return:
 152         """
 153         self.manifest = load_yaml(
 154             os.path.join(
 155                 self.package_content_path, "META-INF/MANIFEST.MF"))
 156
 157     def _load_nsd(self):
 158         """
 159         Load the entry NSD YAML and keep it as dict.
 160         :return:
 161         """
 162         if "entry_service_template" in self.manifest:
 163             nsd_path = os.path.join(
 164                 self.package_content_path,
 165                 make_relative_path(self.manifest.get("entry_service_template")))
 166             self.nsd = load_yaml(nsd_path)
 167             LOG.debug("Loaded NSD: %r" % self.nsd.get("ns_name"))
 168
 169     def _load_vnfd(self):
 170         """
 171         Load all VNFD YAML files referenced in MANIFEST.MF and keep them in dict.
 172         :return:
 173         """
 174         if "package_content" in self.manifest:
 175             for pc in self.manifest.get("package_content"):
 176                 if pc.get("content-type") == "application/sonata.function_descriptor":
 177                     vnfd_path = os.path.join(
 178                         self.package_content_path,
 179                         make_relative_path(pc.get("name")))
 180                     vnfd = load_yaml(vnfd_path)
 181                     self.vnfds[vnfd.get("vnf_name")] = vnfd
 182                     LOG.debug("Loaded VNFD: %r" % vnfd.get("vnf_name"))
 183
 184     def _load_docker_files(self):
 185         """
 186         Get all paths to Dockerfiles from VNFDs and store them in dict.
 187         :return:
 188         """
 189         for k, v in self.vnfds.iteritems():
 190             for vu in v.get("virtual_deployment_units"):
 191                 if vu.get("vm_image_format") == "docker":
 192                     vm_image = vu.get("vm_image")
 193                     docker_path = os.path.join(
 194                         self.package_content_path,
 195                         make_relative_path(vm_image))
 196                     self.local_docker_files[k] = docker_path
 197                     LOG.debug("Found Dockerfile: %r" % docker_path)
 198
 199     def _build_images_from_dockerfiles(self):
 200         """
 201         Build Docker images for each local Dockerfile found in the package: self.local_docker_files
 202         """
 203         if GK_STANDALONE_MODE:
 204             return  # do not build anything in standalone mode
 205         dc = DockerClient()
 206         LOG.info("Building %d Docker images (this may take several minutes) ..." % len(self.local_docker_files))
 207         for k, v in self.local_docker_files.iteritems():
 208             for line in dc.build(path=v.replace("Dockerfile", ""), tag=k, rm=False, nocache=False):
 209                 LOG.debug("DOCKER BUILD: %s" % line)
 210             LOG.info("Docker image created: %s" % k)
 211
 212     def _download_predefined_dockerimages(self):
 213         """
 214         If the package contains URLs to pre-build Docker images, we download them with this method.
 215         """
 216         # TODO implement this if we want to be able to download docker images instead of building them
 217         pass
 218
 219     def _check_docker_image_exists(self, image_name):
 220         """
 221         Query the docker service and check if the given image exists
 222         :param image_name: name of the docker image
 223         :return:
 224         """
 225         return len(DockerClient().images(image_name)) > 0
 226
 227     def _calculate_placement(self, algorithm):
 228         """
 229         Do placement by adding the a field "dc" to
 230         each VNFD that points to one of our
 231         data center objects known to the gatekeeper.
 232         """
 233         assert(len(self.vnfds) > 0)
 234         assert(len(GK.dcs) > 0)
 235         # instantiate algorithm an place
 236         p = algorithm()
 237         p.place(self.nsd, self.vnfds, GK.dcs)
 238         LOG.info("Using placement algorithm: %r" % p.__class__.__name__)
 239         # lets print the placement result
 240         for name, vnfd in self.vnfds.iteritems():
 241             LOG.info("Placed VNF %r on DC %r" % (name, str(vnfd.get("dc"))))
 242
 243
 244 """
 245 Some (simple) placement algorithms
 246 """
 247
 248
 249 class FirstDcPlacement(object):
 250     """
 251     Placement: Always use one and the same data center from the GK.dcs dict.
 252     """
 253     def place(self, nsd, vnfds, dcs):
 254         for name, vnfd in vnfds.iteritems():
 255             vnfd["dc"] = list(dcs.itervalues())[0]
 256
 257
 258 """
 259 Resource definitions and API endpoints
 260 """
 261
 262
 263 class Packages(fr.Resource):
 264
 265     def post(self):
 266         """
 267         Upload a *.son service package to the dummy gatekeeper.
 268
 269         We expect request with a *.son file and store it in UPLOAD_FOLDER
 270         :return: UUID
 271         """
 272         try:
 273             # get file contents
 274             son_file = request.files['file']
 275             # generate a uuid to reference this package
 276             service_uuid = str(uuid.uuid4())
 277             file_hash = hashlib.sha1(str(son_file)).hexdigest()
 278             # ensure that upload folder exists
 279             ensure_dir(UPLOAD_FOLDER)
 280             upload_path = os.path.join(UPLOAD_FOLDER, "%s.son" % service_uuid)
 281             # store *.son file to disk
 282             son_file.save(upload_path)
 283             size = os.path.getsize(upload_path)
 284             # create a service object and register it
 285             s = Service(service_uuid, file_hash, upload_path)
 286             GK.register_service_package(service_uuid, s)
 287             # generate the JSON result
 288             return {"service_uuid": service_uuid, "size": size, "sha1": file_hash, "error": None}
 289         except Exception as ex:
 290             LOG.exception("Service package upload failed:")
 291             return {"service_uuid": None, "size": 0, "sha1": None, "error": "upload failed"}
 292
 293     def get(self):
 294         """
 295         Return a list of UUID's of uploaded service packages.
 296         :return: dict/list
 297         """
 298         return {"service_uuid_list": list(GK.services.iterkeys())}
 299
 300
 301 class Instantiations(fr.Resource):
 302
 303     def post(self):
 304         """
 305         Instantiate a service specified by its UUID.
 306         Will return a new UUID to identify the running service instance.
 307         :return: UUID
 308         """
 309         # try to extract the service uuid from the request
 310         json_data = request.get_json(force=True)
 311         service_uuid = json_data.get("service_uuid")
 312
 313         # lets be a bit fuzzy here to make testing easier
 314         if service_uuid is None and len(GK.services) > 0:
 315             # if we don't get a service uuid, we simple start the first service in the list
 316             service_uuid = list(GK.services.iterkeys())[0]
 317
 318         if service_uuid in GK.services:
 319             # ok, we have a service uuid, lets start the service
 320             service_instance_uuid = GK.services.get(service_uuid).start_service()
 321             return {"service_instance_uuid": service_instance_uuid}
 322         return "Service not found", 404
 323
 324     def get(self):
 325         """
 326         Returns a list of UUIDs containing all running services.
 327         :return: dict / list
 328         """
 329         return {"service_instance_list": [
 330             list(s.instances.iterkeys()) for s in GK.services.itervalues()]}
 331
 332
 333 # create a single, global GK object
 334 GK = Gatekeeper()
 335 # setup Flask
 336 app = Flask(__name__)
 337 app.config['MAX_CONTENT_LENGTH'] = 512 * 1024 * 1024  # 512 MB max upload
 338 api = fr.Api(app)
 339 # define endpoints
 340 api.add_resource(Packages, '/api/packages')
 341 api.add_resource(Instantiations, '/api/instantiations')
 342
 343
 344 def start_rest_api(host, port, datacenters=dict()):
 345     GK.dcs = datacenters
 346     # start the Flask server (not the best performance but ok for our use case)
 347     app.run(host=host,
 348             port=port,
 349             debug=True,
 350             use_reloader=False  # this is needed to run Flask in a non-main thread
 351             )
 352
 353
 354 def ensure_dir(name):
 355     if not os.path.exists(name):
 356         os.makedirs(name)
 357
 358
 359 def load_yaml(path):
 360     with open(path, "r") as f:
 361         try:
 362             r = yaml.load(f)
 363         except yaml.YAMLError as exc:
 364             LOG.exception("YAML parse error")
 365             r = dict()
 366     return r
 367
 368
 369 def make_relative_path(path):
 370     if path.startswith("file://"):
 371         path = path.replace("file://", "", 1)
 372     if path.startswith("/"):
 373         path = path.replace("/", "", 1)
 374     return path
 375
 376
 377 if __name__ == '__main__':
 378     """
 379     Lets allow to run the API in standalone mode.
 380     """
 381     GK_STANDALONE_MODE = True
 382     logging.getLogger("werkzeug").setLevel(logging.INFO)
 383     start_rest_api("0.0.0.0", 8000)
 384