Add Dashboard Listener

JIRA: N/A

Adds source/pharos.py, which will periodically poll the paros
dashboard api to see if any new bookings have started on and of your
dev pods. If a new booking is starting, a deployment will be
started for that pod.

source/listen.py starts the pharos listener in a background
process, so that it will not eat your terminal.

Change-Id: Icbce4453c772f04215f25534606456caa1012f5a
Signed-off-by: Parker Berberian <pberberian@iol.unh.edu>

diff --git a/tools/laas-fog/source/listen.py b/tools/laas-fog/source/listen.py
new file mode 100755 (executable)
index 0000000..ed714c9
--- /dev/null
+++ b/tools/laas-fog/source/listen.py
@@ -0,0 +1,59 @@
+#!/usr/bin/python
+"""
+#############################################################################
+#Copyright 2017 Parker Berberian and others                                 #
+#                                                                           #
+#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.                                             #
+#############################################################################
+"""
+import subprocess
+import sys
+import os
+import yaml
+
+"""
+This is the file that the user will execute to start the whole process.
+This file will start the pharos api listener in a new process and then exit.
+"""
+
+
+def checkArgs():
+    """
+    error checks the cmd line args and gets the path
+    of the config file
+    """
+    usage = "./listen.py --config <path_to_pharos_config>"
+    if "--help" in sys.argv:
+        print usage
+        sys.exit(0)
+
+    if "--config" not in sys.argv:
+        print usage
+        sys.exit(1)
+
+    try:
+        i = sys.argv.index("--config")
+        config_file = sys.argv[i+1]
+        # verifies that the file exists, is readable, and formatted correctly
+        yaml.safe_load(open(config_file))
+        return config_file
+    except Exception:
+        print "Bad config file"
+        sys.exit(1)
+
+
+# reads args and starts the pharos listener in the background
+config = checkArgs()
+source_dir = os.path.dirname(os.path.realpath(__file__))
+pharos_path = os.path.join(source_dir, "pharos.py")
+subprocess.Popen(['/usr/bin/python', pharos_path, '--config', config])

diff --git a/tools/laas-fog/source/pharos.py b/tools/laas-fog/source/pharos.py
new file mode 100755 (executable)
index 0000000..d5a6e8a
--- /dev/null
+++ b/tools/laas-fog/source/pharos.py
@@ -0,0 +1,217 @@
+#!/usr/bin/python
+"""
+#############################################################################
+#Copyright 2017 Parker Berberian and others                                 #
+#                                                                           #
+#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.                                             #
+#############################################################################
+"""
+
+import requests
+import time
+import calendar
+import subprocess
+import sys
+import yaml
+import os
+import logging
+from utilities import Utilities
+from database import BookingDataBase
+
+
+class Pharos_api:
+    """
+    This class listens to the dashboard and starts/stops bookings accordingly.
+    This class should run in the background indefinitely.
+    Do not execute this file directly - run ./listen.py instead
+    """
+    def __init__(self, config):
+        """
+        init function.
+        config is the already-parsed config file
+        """
+        self.conf = config
+        self.servers = yaml.safe_load(open(config['inventory']))
+        self.log = self.createLogger("pharos_api")
+        self.polling = 60 / int(config['polling'])
+        self.log.info(
+                "polling the dashboard once every %d seconds", self.polling)
+        self.dashboard = config['dashboard']
+        self.log.info("connecting to dashboard at %s", self.dashboard)
+        if os.path.isfile(config['token']):
+            self.token = open(config['token']).read()
+        else:
+            self.token = config['token']
+        self.updateHeader()
+        self.database = BookingDataBase(config['database'])
+        self.log.info("using database at %s", self.conf['database'])
+        self.deploy_path = os.path.join(
+                os.path.dirname(os.path.realpath(__file__)), "deploy.py")
+        if not os.path.isfile(self.deploy_path):
+            self.log.error(
+                "Cannot find the deployment script at %s", self.deploy_path)
+
+    def setToken(self, token):
+        """
+        Sets authentication token. Not yet needed.
+        """
+        self.token = token
+        self.updateHeader()
+
+    def setTokenFromFile(self, path):
+        """
+        reads auth token from a file. Not yet needed.
+        """
+        self.setToken(open(path).read())
+
+    def updateHeader(self):
+        """
+        updates the http header used when talking to the dashboard
+        """
+        self.header = {"Authorization": "Token " + self.token}
+
+    def listen(self):
+        """
+        this method will continuously poll the pharos dashboard.
+        If a booking is found on our server,
+        we will start a deployment in the background with the
+        proper config file for the requested
+        installer and scenario.
+        """
+        self.log.info("%s", "Beginning polling of dashboard")
+        try:
+            while True:
+                time.sleep(self.polling)
+                url = self.dashboard+"/api/bookings/"
+                bookings = requests.get(url, headers=self.header).json()
+                for booking in bookings:
+                    if booking['resource_id'] in self.servers.keys():
+                        self.convertTimes(booking)
+                        self.database.checkAddBooking(booking)
+                self.checkBookings()
+        except Exception:
+            self.log.exception('%s', "failed to connect to dashboard")
+
+            self.listen()
+
+    def convertTimes(self, booking):
+        """
+        this method will take the time reported by Pharos in the
+        format yyyy-mm-ddThh:mm:ssZ
+        and convert it into seconds since the epoch,
+        for easier management
+        """
+        booking['start'] = self.pharosToEpoch(booking['start'])
+        booking['end'] = self.pharosToEpoch(booking['end'])
+
+    def pharosToEpoch(self, timeStr):
+        """
+        Converts the dates from the dashboard to epoch time.
+        """
+        time_struct = time.strptime(timeStr, '%Y-%m-%dT%H:%M:%SZ')
+        epoch_time = calendar.timegm(time_struct)
+        return epoch_time
+
+    def checkBookings(self):
+        """
+        This method checks all the bookings in our database to see if any
+        action is required.
+        """
+        # get all active bookings from database into a usable form
+        bookings = self.database.getBookings()
+        for booking in bookings:
+            # first, check if booking is over
+            if time.time() > booking[3]:
+                self.log.info("ending the booking with id %i", booking[0])
+                self.endBooking(booking)
+            # Then check if booking has begun and the host is still idle
+            elif time.time() > booking[2] and booking[7] < 1:
+                self.log.info("starting the booking with id %i", booking[0])
+                self.startBooking(booking)
+
+    def startBooking(self, booking):
+        """
+        Starts the scheduled booking on the requested host with
+        the correct config file.
+        The provisioning process gets spun up in a subproccess,
+        so the api listener is not interupted.
+        """
+        try:
+            host = self.servers[booking[1]]
+            self.log.info("Detected a new booking started for host %s", host)
+            config_file = self.conf['default_configs']["None"]
+            try:
+                config_file = self.conf['default_configs'][booking[4]]
+            except KeyError:
+                self.log.warning(
+                        "No installer detected in the booking request.")
+            self.log.info("New booking started for host %s", host)
+            self.database.setStatus(booking[0], 1)  # mark booking started
+            if not os.path.isfile(self.deploy_path):
+                error = "Cannot find the deploment script at %s"
+                self.log.error(error, self.deploy_path)
+            subprocess.Popen([
+                '/usr/bin/python',
+                self.deploy_path,
+                '--config', config_file,
+                '--host', host
+                ])
+        except Exception:
+            self.log.exception("Failed to start booking for %s", host)
+
+    def endBooking(self, booking):
+        """
+        Resets a host once its booking has ended.
+        """
+        try:
+            try:
+                config_file = self.conf['default_configs'][booking[4]]
+            except KeyError:
+                warn = "No installer detected in booking request"
+                self.log.warning("%s", warn)
+                config_file = self.conf['default_configs']["None"]
+
+            host = self.servers[booking[1]]
+            log = logging.getLogger(host)
+            log.info('Lease expired. Resetting host %s', host)
+            self.database.setStatus(booking[0], 3)
+            if not os.path.isfile(self.deploy_path):
+                err = "Cannot find deployment script at %s"
+                self.log.error(err, self.deploy_path)
+            subprocess.Popen([
+                '/usr/bin/python',
+                self.deploy_path,
+                '--config', config_file,
+                '--host', host,
+                '--reset'
+                ])
+            self.database.removeBooking(booking[0])
+        except Exception:
+            self.log.exception("Failed to end booking for %s", host)
+
+    def createLogger(self, name):
+        return Utilities.createLogger(name, self.conf['logging_dir'])
+
+
+if __name__ == "__main__":
+    if "--config" not in sys.argv:
+        print "Specify config file with --config option"
+        sys.exit(1)
+    config = None
+    try:
+        config_file = sys.argv[1+sys.argv.index('--config')]
+        config = yaml.safe_load(open(config_file))
+    except Exception:
+        sys.exit(1)
+    api = Pharos_api(config)
+    api.listen()