ceilometer/ceilometer/objectstore/swift_middleware.py

#!/usr/bin/env python
#
# Copyright 2012 eNovance <licensing@enovance.com>
#
# Author: Julien Danjou <julien@danjou.info>
#
# 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.


"""
Ceilometer Middleware for Swift Proxy

Configuration:

In /etc/swift/proxy-server.conf on the main pipeline add "ceilometer" just
before "proxy-server" and add the following filter in the file:

.. code-block:: python

    [filter:ceilometer]
    use = egg:ceilometer#swift

    # Some optional configuration
    # this allow to publish additional metadata
    metadata_headers = X-TEST

    # Set reseller prefix (defaults to "AUTH_" if not set)
    reseller_prefix = AUTH_
"""

from __future__ import absolute_import
import logging

from oslo.utils import timeutils
import six
import six.moves.urllib.parse as urlparse

from ceilometer.openstack.common import context
from ceilometer import pipeline
from ceilometer import sample
from ceilometer import service


class InputProxy(object):
    """File-like object that counts bytes read.

    To be swapped in for wsgi.input for accounting purposes.
    Borrowed from swift.common.utils. Duplidated here to avoid
    dependency on swift package.
    """
    def __init__(self, wsgi_input):
        self.wsgi_input = wsgi_input
        self.bytes_received = 0

    def read(self, *args, **kwargs):
        """Pass read request to the underlying file-like object

        Add bytes read to total.
        """
        chunk = self.wsgi_input.read(*args, **kwargs)
        self.bytes_received += len(chunk)
        return chunk

    def readline(self, *args, **kwargs):
        """Pass readline request to the underlying file-like object

        Add bytes read to total.
        """
        line = self.wsgi_input.readline(*args, **kwargs)
        self.bytes_received += len(line)
        return line


class CeilometerMiddleware(object):
    """Ceilometer middleware used for counting requests."""

    def __init__(self, app, conf):
        self.app = app

        self.metadata_headers = [h.strip().replace('-', '_').lower()
                                 for h in conf.get(
                                     "metadata_headers",
                                     "").split(",") if h.strip()]

        self.logger = logging.getLogger('ceilometer')
        self.logger.setLevel(getattr(logging,
                                     conf.get('log_level', 'WARN').upper()))
        service.prepare_service([])

        self.pipeline_manager = pipeline.setup_pipeline()
        self.reseller_prefix = conf.get('reseller_prefix', 'AUTH_')
        if self.reseller_prefix and self.reseller_prefix[-1] != '_':
            self.reseller_prefix += '_'

    def __call__(self, env, start_response):
        start_response_args = [None]
        input_proxy = InputProxy(env['wsgi.input'])
        env['wsgi.input'] = input_proxy

        def my_start_response(status, headers, exc_info=None):
            start_response_args[0] = (status, list(headers), exc_info)

        def iter_response(iterable):
            iterator = iter(iterable)
            try:
                chunk = next(iterator)
                while not chunk:
                    chunk = next(iterator)
            except StopIteration:
                chunk = ''

            if start_response_args[0]:
                start_response(*start_response_args[0])
            bytes_sent = 0
            try:
                while chunk:
                    bytes_sent += len(chunk)
                    yield chunk
                    chunk = next(iterator)
            finally:
                try:
                    self.publish_sample(env,
                                        input_proxy.bytes_received,
                                        bytes_sent)
                except Exception:
                    self.logger.exception('Failed to publish samples')

        try:
            iterable = self.app(env, my_start_response)
        except Exception:
            self.publish_sample(env, input_proxy.bytes_received, 0)
            raise
        else:
            return iter_response(iterable)

    def publish_sample(self, env, bytes_received, bytes_sent):
        path = urlparse.quote(env['PATH_INFO'])
        method = env['REQUEST_METHOD']
        headers = {}
        for header in env:
            if header.startswith('HTTP_') and env[header]:
                key = header[5:]
                if isinstance(env[header], six.text_type):
                    headers[key] = env[header].encode('utf-8')
                else:
                    headers[key] = str(env[header])

        try:
            container = obj = None
            version, account, remainder = path.replace(
                '/', '', 1).split('/', 2)
            if not version or not account:
                raise ValueError('Invalid path: %s' % path)
            if remainder:
                if '/' in remainder:
                    container, obj = remainder.split('/', 1)
                else:
                    container = remainder
        except ValueError:
            return

        now = timeutils.utcnow().isoformat()

        resource_metadata = {
            "path": path,
            "version": version,
            "container": container,
            "object": obj,
        }

        for header in self.metadata_headers:
            if header.upper() in headers:
                resource_metadata['http_header_%s' % header] = headers.get(
                    header.upper())

        with self.pipeline_manager.publisher(
                context.get_admin_context()) as publisher:
            if bytes_received:
                publisher([sample.Sample(
                    name='storage.objects.incoming.bytes',
                    type=sample.TYPE_DELTA,
                    unit='B',
                    volume=bytes_received,
                    user_id=env.get('HTTP_X_USER_ID'),
                    project_id=env.get('HTTP_X_TENANT_ID'),
                    resource_id=account.partition(self.reseller_prefix)[2],
                    timestamp=now,
                    resource_metadata=resource_metadata)])

            if bytes_sent:
                publisher([sample.Sample(
                    name='storage.objects.outgoing.bytes',
                    type=sample.TYPE_DELTA,
                    unit='B',
                    volume=bytes_sent,
                    user_id=env.get('HTTP_X_USER_ID'),
                    project_id=env.get('HTTP_X_TENANT_ID'),
                    resource_id=account.partition(self.reseller_prefix)[2],
                    timestamp=now,
                    resource_metadata=resource_metadata)])

            # publish the event for each request
            # request method will be recorded in the metadata
            resource_metadata['method'] = method.lower()
            publisher([sample.Sample(
                name='storage.api.request',
                type=sample.TYPE_DELTA,
                unit='request',
                volume=1,
                user_id=env.get('HTTP_X_USER_ID'),
                project_id=env.get('HTTP_X_TENANT_ID'),
                resource_id=account.partition(self.reseller_prefix)[2],
                timestamp=now,
                resource_metadata=resource_metadata)])


def filter_factory(global_conf, **local_conf):
    conf = global_conf.copy()
    conf.update(local_conf)

    def ceilometer_filter(app):
        return CeilometerMiddleware(app, conf)
    return ceilometer_filter