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