Merge "Add a mini-cinder volume create with resumption"

This commit is contained in:
Jenkins
2013-10-11 18:12:39 +00:00
committed by Gerrit Code Review

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@@ -0,0 +1,153 @@
# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright (C) 2013 Yahoo! Inc. 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.
import contextlib
import hashlib
import logging
import os
import random
import sys
import time
logging.basicConfig(level=logging.ERROR)
top_dir = os.path.abspath(os.path.join(os.path.dirname(__file__),
os.pardir,
os.pardir))
sys.path.insert(0, top_dir)
from taskflow.patterns import graph_flow as gf
from taskflow.patterns import linear_flow as lf
from taskflow import engines
from taskflow import task
from taskflow.persistence import backends
from taskflow.utils import eventlet_utils as e_utils
from taskflow.utils import persistence_utils as p_utils
@contextlib.contextmanager
def slow_down(how_long=0.5):
try:
yield how_long
finally:
print("** Ctrl-c me please!!! **")
time.sleep(how_long)
def find_flow_detail(backend, book_id, flow_id):
with contextlib.closing(backend.get_connection()) as conn:
lb = conn.get_logbook(book_id)
return lb.find(flow_id)
def get_backend():
try:
backend_uri = sys.argv[1]
except Exception:
backend_uri = 'sqlite://'
backend = backends.fetch({'connection': backend_uri})
backend.get_connection().upgrade()
return backend
class PrintText(task.Task):
def __init__(self, print_what, no_slow=False):
content_hash = hashlib.md5(print_what).hexdigest()[0:8]
super(PrintText, self).__init__(name="Print: %s" % (content_hash))
self._text = print_what
self._no_slow = no_slow
def execute(self):
if self._no_slow:
print("-" * (len(self._text)))
print(self._text)
print("-" * (len(self._text)))
else:
with slow_down():
print("-" * (len(self._text)))
print(self._text)
print("-" * (len(self._text)))
class CreateSpecForVolumes(task.Task):
def execute(self):
volumes = []
for i in range(0, random.randint(1, 10)):
volumes.append({
'type': 'disk',
'location': "/dev/vda%s" % (i + 1),
})
return volumes
class PrepareVolumes(task.Task):
def execute(self, volume_specs):
for v in volume_specs:
with slow_down():
print("Dusting off your hard drive %s" % (v))
with slow_down():
print("Taking a well deserved break.")
print("Your drive %s has been certified." % (v))
# Setup the set of things to do (mini-cinder).
flow = lf.Flow("root").add(
PrintText("Starting volume create", no_slow=True),
gf.Flow('maker').add(
CreateSpecForVolumes("volume_specs", provides='volume_specs'),
PrintText("I need a nap, it took me a while to build those specs."),
PrepareVolumes(),
),
PrintText("Finished volume create", no_slow=True))
# Setup the persistence & resumption layer.
backend = get_backend()
try:
book_id, flow_id = sys.argv[2].split("+", 1)
except (IndexError, ValueError):
book_id = None
flow_id = None
if not all([book_id, flow_id]):
logbook = p_utils.temporary_log_book(backend)
flow_detail = p_utils.create_flow_detail(flow, logbook, backend)
print("!! Your tracking id is: '%s+%s'" % (logbook.uuid, flow_detail.uuid))
print("!! Please submit this on later runs for tracking purposes")
else:
flow_detail = find_flow_detail(backend, book_id, flow_id)
# Annnnd load and run.
engine = engines.load(flow,
flow_detail=flow_detail,
backend=backend,
engine_conf={
'engine': 'parallel',
'executor': e_utils.GreenExecutor(10),
})
engine.run()
# How to use.
#
# 1. $ python me.py "sqlite:////tmp/cinder.db"
# 2. ctrl-c before this finishes
# 3. Find the tracking id (search for 'Your tracking id is')
# 4. $ python me.py "sqlite:////tmp/cinder.db" "$tracking_id"
# 5. Profit!