296 lines
12 KiB
ReStructuredText
296 lines
12 KiB
ReStructuredText
..
|
|
Copyright 2018 Catalyst IT Ltd
|
|
All Rights Reserved.
|
|
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.
|
|
|
|
Function Cookbook
|
|
=================
|
|
|
|
Introduction
|
|
~~~~~~~~~~~~
|
|
|
|
Qinling function lets you execute your code in a serverless environment without
|
|
having to first create a VM or container. This cookbook contains several
|
|
examples for how to create functions in Qinling.
|
|
|
|
Examples
|
|
~~~~~~~~
|
|
|
|
Create python function with libraries in a package
|
|
--------------------------------------------------
|
|
|
|
This guide describes how to create a python function with libraries in a
|
|
package and how to invoke the function in a Python runtime(the steps assume
|
|
there is already a Python 2.7 runtime available in the deployment).
|
|
|
|
The function resizes an image which stores in Swift and uploads the resized
|
|
image to a new container with a same object name. For the function to work, a
|
|
python library called ``Pillow`` needs to be installed together with the
|
|
function code, the ``python-swiftclient`` doesn't need to be installed because
|
|
Qinling supports it as a built-in library in Qinling's default Python 2.7
|
|
runtime implementation.
|
|
|
|
The function needs two positional parameters:
|
|
|
|
* ``container_name``: The container name in Swift that the original image file
|
|
is stored in.
|
|
* ``object_name``: The object name in the container.
|
|
|
|
There is no output for the function itself, but you can check the function
|
|
execution log to see the whole process.
|
|
|
|
.. note::
|
|
|
|
The following process has been tested in a Devstack environment in which
|
|
Swift is also installed.
|
|
|
|
#. Create a directory, for example ``~/qinling_test``
|
|
|
|
.. code-block:: console
|
|
|
|
$ mkdir ~/qinling_test
|
|
|
|
.. end
|
|
|
|
#. Write a custom python code for resizing an image at the root level of the
|
|
directory created above.
|
|
|
|
.. code-block:: console
|
|
|
|
$ cat <<EOF > ~/qinling_test/resize_image.py
|
|
import os
|
|
|
|
from PIL import Image
|
|
import swiftclient
|
|
from swiftclient.exceptions import ClientException
|
|
|
|
|
|
def resize_image(image_path, resized_path):
|
|
with Image.open(image_path) as image:
|
|
image.thumbnail(tuple(x / 4 for x in image.size))
|
|
image.save(resized_path)
|
|
|
|
|
|
def main(context, container_name, object_name):
|
|
conn = swiftclient.Connection(
|
|
session=context['os_session'],
|
|
os_options={'region_name': 'RegionOne'},
|
|
)
|
|
|
|
# Download original image
|
|
image_path = os.path.abspath('./%s' % object_name)
|
|
_, obj_contents = conn.get_object(container_name, object_name)
|
|
with open(image_path, 'w') as local:
|
|
local.write(obj_contents)
|
|
|
|
print('Downloaded object %s from container %s' % (object_name, container_name))
|
|
|
|
thumb_path = os.path.abspath('./%s_resized.png' % object_name)
|
|
resize_image(image_path, thumb_path)
|
|
|
|
print('Resized.')
|
|
|
|
# Create new container if needed
|
|
new_container_name = '%s_resized' % container_name
|
|
try:
|
|
conn.head_container(new_container_name)
|
|
except ClientException:
|
|
conn.put_container(new_container_name)
|
|
print("New container %s created." % new_container_name)
|
|
|
|
# Upload resized image
|
|
with open(thumb_path, 'r') as new_local:
|
|
conn.put_object(
|
|
new_container_name,
|
|
object_name,
|
|
contents=new_local,
|
|
content_type='text/plain'
|
|
)
|
|
os.remove(image_path)
|
|
os.remove(thumb_path)
|
|
|
|
print('Uploaded object %s to container %s' % (object_name, new_container_name))
|
|
EOF
|
|
|
|
.. end
|
|
|
|
#. Install the python libraries necessary for the program execution using
|
|
``pip``. The libraries need to be installed at the root level of the
|
|
directory.
|
|
|
|
.. code-block:: console
|
|
|
|
pip install module-name -t path/to/dir
|
|
|
|
.. end
|
|
|
|
In this example, we would install the library ``Pillow`` in the project
|
|
directory.
|
|
|
|
.. code-block:: console
|
|
|
|
$ pip install Pillow -t ~/qinling_test
|
|
|
|
.. end
|
|
|
|
.. note::
|
|
|
|
Qinling's default Python runtime includes most of the OpenStack project
|
|
SDKs, so you don't need to include python-swiftclient in your function
|
|
code package, but you can optionally include it for your local testing.
|
|
|
|
#. Add the contents of the whole directory to a zip file which is now your
|
|
function code package. Make sure you zip the contents of the directory and
|
|
not the directory itself.
|
|
|
|
.. code-block:: console
|
|
|
|
$ cd ~/qinling_test; zip -r9 ~/qinling_test/resize_image.zip .
|
|
|
|
.. end
|
|
|
|
#. Create function and get the function ID, replace the ``runtime_id`` with
|
|
the one in your deployment.
|
|
|
|
.. code-block:: console
|
|
|
|
$ runtime_id=601efeb8-3e41-4e5c-a12a-986dbda252e3
|
|
$ openstack function create --name resize_image \
|
|
--runtime $runtime_id \
|
|
--entry resize_image.main \
|
|
--package ~/qinling_test/resize_image.zip
|
|
+-------------+-------------------------------------------------------------------------+
|
|
| Field | Value |
|
|
+-------------+-------------------------------------------------------------------------+
|
|
| id | f8b18de6-1751-46d6-8c0d-0f1ecf943d12 |
|
|
| name | resize_test |
|
|
| description | None |
|
|
| count | 0 |
|
|
| code | {u'source': u'package', u'md5sum': u'ae7ad9ae450a8c5c31dca8e96f42247c'} |
|
|
| runtime_id | 685c1e6c-e175-4b32-9ec4-244d39c1077e |
|
|
| entry | resize_image.main |
|
|
| project_id | a1e58c83923a4e2ca9370df6007c7fe6 |
|
|
| created_at | 2018-07-03 04:38:50.147277 |
|
|
| updated_at | None |
|
|
| cpu | 100 |
|
|
| memory_size | 33554432 |
|
|
+-------------+-------------------------------------------------------------------------+
|
|
$ function_id=f8b18de6-1751-46d6-8c0d-0f1ecf943d12
|
|
|
|
.. end
|
|
|
|
#. Upload an image to Swift.
|
|
|
|
.. code-block:: console
|
|
|
|
$ curl -SL https://docs.openstack.org/arch-design/_images/osog_0001.png -o ~/origin.jpg
|
|
$ openstack container create origin_folder
|
|
+---------------------------------------+---------------+------------------------------------+
|
|
| account | container | x-trans-id |
|
|
+---------------------------------------+---------------+------------------------------------+
|
|
| AUTH_a1e58c83923a4e2ca9370df6007c7fe6 | origin_folder | tx664a23a4a6e345b6af30d-005b3b6127 |
|
|
+---------------------------------------+---------------+------------------------------------+
|
|
$ openstack object create origin_folder ~/origin.jpg --name image
|
|
+--------+---------------+----------------------------------+
|
|
| object | container | etag |
|
|
+--------+---------------+----------------------------------+
|
|
| image | origin_folder | 07855978284adfcbbf76954a7c654a74 |
|
|
+--------+---------------+----------------------------------+
|
|
$ openstack object show origin_folder image
|
|
+----------------+---------------------------------------+
|
|
| Field | Value |
|
|
+----------------+---------------------------------------+
|
|
| account | AUTH_a1e58c83923a4e2ca9370df6007c7fe6 |
|
|
| container | origin_folder |
|
|
| content-length | 45957 |
|
|
| content-type | application/octet-stream |
|
|
| etag | 07855978284adfcbbf76954a7c654a74 |
|
|
| last-modified | Tue, 03 Jul 2018 11:44:33 GMT |
|
|
| object | image |
|
|
+----------------+---------------------------------------+
|
|
|
|
.. end
|
|
|
|
#. Invoke the function by specifying function_id and the function inputs as
|
|
well.
|
|
|
|
.. code-block:: console
|
|
|
|
$ openstack function execution create $function_id --input '{"container_name": "origin_folder", "object_name": "image"}'
|
|
+------------------+-------------------------------------------------------------+
|
|
| Field | Value |
|
|
+------------------+-------------------------------------------------------------+
|
|
| id | 04c60ae7-08c9-454c-9b2c-0bbf36391159 |
|
|
| function_id | d3de49fc-7488-4635-aa48-84e754881eb8 |
|
|
| function_version | 0 |
|
|
| description | None |
|
|
| input | {"object_name": "image", "container_name": "origin_folder"} |
|
|
| result | {"duration": 2.74, "output": null} |
|
|
| status | success |
|
|
| sync | True |
|
|
| project_id | a1e58c83923a4e2ca9370df6007c7fe6 |
|
|
| created_at | 2018-07-03 09:12:12 |
|
|
| updated_at | 2018-07-03 09:12:16 |
|
|
+------------------+-------------------------------------------------------------+
|
|
|
|
.. end
|
|
|
|
#. Check the function execution log.
|
|
|
|
.. code-block:: console
|
|
|
|
$ openstack function execution log show 04c60ae7-08c9-454c-9b2c-0bbf36391159
|
|
Start execution: 04c60ae7-08c9-454c-9b2c-0bbf36391159
|
|
Downloaded object image from container origin_folder
|
|
Resized.
|
|
New container origin_folder_resized created.
|
|
Uploaded object image to container origin_folder_resized
|
|
Finished execution: 04c60ae7-08c9-454c-9b2c-0bbf36391159
|
|
|
|
.. end
|
|
|
|
#. Verify that a new object of smaller size was created in a new container in
|
|
Swift.
|
|
|
|
.. code-block:: console
|
|
|
|
$ openstack container list
|
|
+-----------------------+
|
|
| Name |
|
|
+-----------------------+
|
|
| origin_folder |
|
|
| origin_folder_resized |
|
|
+-----------------------+
|
|
$ openstack object list origin_folder_resized
|
|
+-------+
|
|
| Name |
|
|
+-------+
|
|
| image |
|
|
+-------+
|
|
$ openstack object show origin_folder_resized image
|
|
+----------------+---------------------------------------+
|
|
| Field | Value |
|
|
+----------------+---------------------------------------+
|
|
| account | AUTH_a1e58c83923a4e2ca9370df6007c7fe6 |
|
|
| container | origin_folder_resized |
|
|
| content-length | 31779 |
|
|
| content-type | text/plain |
|
|
| etag | f737cc7f0fe5c15d8a6897c8fe159c02 |
|
|
| last-modified | Tue, 03 Jul 2018 11:46:40 GMT |
|
|
| object | image |
|
|
+----------------+---------------------------------------+
|
|
|
|
.. end
|
|
|
|
Pay attention to the object ``content-length`` value which is smaller than
|
|
the original object.
|