#!/usr/bin/python
#
# Copyright 2015 The Cluster-Insight Authors. 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.
"""Runs the cluster insight data collector.
Collects context metadata from the Kubernetes API and computes a graph from it.
"""
import argparse
import sys
import flask
from flask_cors import CORS
# local imports
import collector_error
import constants
import context
import global_state
import kubernetes
import utilities
app = flask.Flask(__name__)
# enable cross-origin resource sharing (CORS) HTTP headers on all routes
cors = CORS(app)
def return_elapsed(gs):
"""Returns a description of the elapsed time of recent operations.
Args:
gs: global state.
Returns:
A dictionary containing the count, minimum elapsed time,
maximum elapsed time, average elapsed time, and list of elapsed time
records.
"""
assert isinstance(gs, global_state.GlobalState)
elapsed_list = []
elapsed_sum = 0.0
elapsed_min = None
elapsed_max = None
for elapsed_record in gs.get_elapsed():
duration = elapsed_record.elapsed_seconds
elapsed_list.append(
{'start_time': utilities.seconds_to_timestamp(
elapsed_record.start_time),
'what': elapsed_record.what,
'threadIdentifier': elapsed_record.thread_identifier,
'elapsed_seconds': duration})
elapsed_sum += duration
if (elapsed_min is None) or (elapsed_max is None):
elapsed_min = duration
elapsed_max = duration
else:
elapsed_min = min(elapsed_min, duration)
elapsed_max = max(elapsed_max, duration)
return {'count': len(elapsed_list),
'min': elapsed_min,
'max': elapsed_max,
'average': elapsed_sum / len(elapsed_list) if elapsed_list else None,
'items': elapsed_list}
@app.route('/', methods=['GET'])
def home():
"""Returns the response of the '/' endpoint.
Returns:
The home page of the Cluster-Insight data collector.
"""
return flask.send_from_directory('static', 'home.html')
@app.route('/cluster/resources/nodes', methods=['GET'])
def get_nodes():
"""Computes the response of the '/cluster/resources/nodes' endpoint.
Returns:
The nodes of the context graph.
"""
gs = app.context_graph_global_state
try:
nodes_list = kubernetes.get_nodes_with_metrics(gs)
except collector_error.CollectorError as e:
return flask.jsonify(utilities.make_error(str(e)))
return flask.jsonify(utilities.make_response(nodes_list, 'resources'))
@app.route('/cluster/resources/services', methods=['GET'])
def get_services():
"""Computes the response of the '/cluster/resources/services' endpoint.
Returns:
The services of the context graph.
"""
gs = app.context_graph_global_state
try:
services_list = kubernetes.get_services(gs)
except collector_error.CollectorError as e:
return flask.jsonify(utilities.make_error(str(e)))
return flask.jsonify(utilities.make_response(services_list, 'resources'))
@app.route('/cluster/resources/rcontrollers', methods=['GET'])
def get_rcontrollers():
"""Computes the response of accessing the '/cluster/resources/rcontrollers'.
Returns:
The replication controllers of the context graph.
"""
gs = app.context_graph_global_state
try:
rcontrollers_list = kubernetes.get_rcontrollers(gs)
except collector_error.CollectorError as e:
return flask.jsonify(utilities.make_error(str(e)))
return flask.jsonify(utilities.make_response(rcontrollers_list, 'resources'))
@app.route('/cluster/resources/pods', methods=['GET'])
def get_pods():
"""Computes the response of the '/cluster/resources/pods' endpoint.
Returns:
The pods of the context graph.
"""
gs = app.context_graph_global_state
try:
pods_list = kubernetes.get_pods(gs)
except collector_error.CollectorError as e:
return flask.jsonify(utilities.make_error(str(e)))
return flask.jsonify(utilities.make_response(pods_list, 'resources'))
@app.route('/debug', methods=['GET'])
def get_debug():
"""Computes the response of the '/cluster/resources/debug' endpoint.
Returns:
The DOT graph depicting the context graph.
"""
gs = app.context_graph_global_state
try:
return context.compute_graph(gs, 'dot')
except collector_error.CollectorError as e:
return flask.jsonify(utilities.make_error(str(e)))
@app.route('/cluster/resources', methods=['GET'])
def get_resources():
"""Computes the response of the '/cluster/resources' endpoint.
Returns:
The 'resources' section of the context graph.
"""
gs = app.context_graph_global_state
try:
response = context.compute_graph(gs, 'resources')
return flask.jsonify(response)
except collector_error.CollectorError as e:
return flask.jsonify(utilities.make_error(str(e)))
@app.route('/cluster', methods=['GET'])
def get_cluster():
"""Computes the response of the '/cluster' endpoint.
Returns:
The entire context graph.
"""
gs = app.context_graph_global_state
try:
response = context.compute_graph(gs, 'context_graph')
return flask.jsonify(response)
except collector_error.CollectorError as e:
return flask.jsonify(utilities.make_error(str(e)))
@app.route('/elapsed', methods=['GET'])
def get_elapsed():
"""Computes the response of the '/elapsed' endpoint.
Returns:
A successful response containing the list of elapsed time records of the
most recent Kubernetes API invocations since the previous call to the
'/elapsed' endpoint. Never returns more than constants.MAX_ELAPSED_QUEUE_SIZE
elapsed time records.
"""
gs = app.context_graph_global_state
result = return_elapsed(gs)
return flask.jsonify(utilities.make_response(result, 'elapsed'))
@app.route('/healthz', methods=['GET'])
def get_health():
"""Computes the response of the '/healthz' endpoint.
Returns:
A successful response containing the attribute 'health' and the value 'OK'.
"""
return flask.jsonify(utilities.make_response('OK', 'health'))
def main():
"""Starts the web server."""
parser = argparse.ArgumentParser(description='Cluster-Insight data collector')
parser.add_argument('-d', '--debug', action='store_true',
help='enable debug mode')
parser.add_argument('--host', action='store', type=str,
default='0.0.0.0',
help='hostname to listen on [default=all interfaces]')
parser.add_argument('-p', '--port', action='store', type=int,
default=constants.DATA_COLLECTOR_PORT,
help='data collector port number [default=%(default)d]')
args = parser.parse_args()
g_state = global_state.GlobalState()
g_state.init_caches_and_synchronization()
app.context_graph_global_state = g_state
app.run(host=args.host, port=args.port, debug=args.debug)
if __name__ == '__main__':
main()
