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_testmkdir ~/qinling_testWrite a custom python code for resizing an image at the root level of the directory created above.
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
Install the python libraries necessary for the program execution using
pip. The libraries need to be installed at the root level of the directory.pip install module-name -t path/to/dirIn this example, we would install the library
Pillowin the project directory.pip install Pillow -t ~/qinling_testNote
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.
cd ~/qinling_test; zip -r9 ~/qinling_test/resize_image.zip .Create function and get the function ID, replace the
runtime_idwith the one in your deployment.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
Upload an image to Swift.
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 | +----------------+---------------------------------------+
Invoke the function by specifying function_id and the function inputs as well.
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 | +------------------+-------------------------------------------------------------+
Check the function execution log.
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
Verify that a new object of smaller size was created in a new container in Swift.
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 | +----------------+---------------------------------------+
Pay attention to the object
content-lengthvalue which is smaller than the original object.
Create a function stored in OpenStack Swift¶
OpenStack object storage service, swift can be integrated with Qinling to
create functions. You can upload your function package to swift and create
the function by specifying the container name and object name in Swift. In this
example the function would return "Hello, World" by default, you can
replace the string with the function input. The steps assume there is already
a Python 2.7 runtime available in the deployment.
Create a function deployment package.
mkdir ~/qinling_swift_test cd ~/qinling_swift_test cat <<EOF > hello_world.py def main(name='World',**kwargs): ret = 'Hello, %s' % name return ret EOF cd ~/qinling_swift_test && zip -r ~/qinling_swift_test/hello_world.zip ./*
Upload the file to swift
openstack container create functions +---------------------------------------+------------------+------------------------------------+ | account | container | x-trans-id | +---------------------------------------+------------------+------------------------------------+ | AUTH_6ae7142bff0542d8a8f3859ffa184236 | functions | 9b45bef5ab2658acb9b72ee32f39dbc8 | +---------------------------------------+------------------+------------------------------------+ openstack object create functions hello_world.zip +-----------------+-----------+----------------------------------+ | object | container | etag | +-----------------+-----------+----------------------------------+ | hello_world.zip | functions | 9b45bef5ab2658acb9b72ee32f39dbc8 | +-----------------+-----------+----------------------------------+ openstack object show functions hello_world.zip +----------------+---------------------------------------+ | Field | Value | +----------------+---------------------------------------+ | account | AUTH_6ae7142bff0542d8a8f3859ffa184236 | | container | functions | | content-length | 246 | | content-type | application/zip | | etag | 9b45bef5ab2658acb9b72ee32f39dbc8 | | last-modified | Wed, 18 Jul 2018 17:45:23 GMT | | object | hello_world.zip | +----------------+---------------------------------------+
Create a function and get the function ID, replace the
runtime_idwith the one in your deployment. Also, specify swift container and object name.openstack function create --name hello_world \ --runtime $runtime_id \ --entry hello_world.main \ --container functions \ --object hello_world.zip +-------------+----------------------------------------------------------------------------------------------+ | Field | Value | +-------------+----------------------------------------------------------------------------------------------+ | id | f1102bca-fbb4-4baf-874d-ed33bf8251f7 | | name | hello_world | | description | None | | count | 0 | | code | {u'source': u'swift', u'swift': {u'object': u'hello_world.zip', u'container': u'functions'}} | | runtime_id | 0d8bcf73-910b-4fec-86b1-38ace8bd0766 | | entry | hello_world.main | | project_id | 6ae7142bff0542d8a8f3859ffa184236 | | created_at | 2018-07-18 17:46:29.974506 | | updated_at | None | | cpu | 100 | | memory_size | 33554432 | +-------------+----------------------------------------------------------------------------------------------+
Invoke the function by specifying function_id
function_id=f1102bca-fbb4-4baf-874d-ed33bf8251f7 openstack function execution create $function_id +------------------+-----------------------------------------------+ | Field | Value | +------------------+-----------------------------------------------+ | id | 3451393d-60c6-4172-bbdf-c681929fae07 | | function_id | f1102bca-fbb4-4baf-874d-ed33bf8251f7 | | function_version | 0 | | description | None | | input | None | | result | {"duration": 0.031, "output": "Hello, World"} | | status | success | | sync | True | | project_id | 6ae7142bff0542d8a8f3859ffa184236 | | created_at | 2018-07-18 17:49:46 | | updated_at | 2018-07-18 17:49:48 | +------------------+-----------------------------------------------+
It is very easy and simple to use Qinling with swift. We have successfully created and invoked a function using OpenStack Swift.
Create image(docker) type function¶
With the help of Docker Hub you would be able to create image type functions in
Qinling. As a prerequisite, you need to have a Docker Hub account. In the
following instructions replace DOCKER_USER with your own docker hub
username.
In this tutorial we would be create docker image with latest Python3 installed. We will create a python script which would be included in the image. Finally we create a Dockerfile to build the image.
mkdir ~/qinling_test cd ~/qinling_test cat <<EOF > ~/qinling_test/hello.py import sys import time def main(): print('Hello', sys.argv[1]) time.sleep(3) if __name__ == '__main__': main() EOF cat <<EOF > ~/qinling_test/Dockerfile FROM python:3.7.0-alpine3.7 COPY . /qinling_test WORKDIR /qinling_test ENTRYPOINT [ "python", "./hello.py" ] CMD ["Qinling"] EOF
You need first run docker login to authenticate, build the image and push to Docker Hub.
docker login docker build -t DOCKER_USER/qinling_test . docker push DOCKER_USER/qinlng_test
Create an image type function by providing the docker image name.
$ openstack function create --name docker_test --image DOCKER_USER/qinling_test +-------------+--------------------------------------------------------------+ | Field | Value | +-------------+--------------------------------------------------------------+ | id | 6fa6932d-ee43-41d4-891c-77a96b52c697 | | name | docker_test | | description | None | | count | 0 | | code | {u'source': u'image', u'image': u'DOCKER_USER/qinling_test'} | | runtime_id | None | | entry | None | | project_id | 6ae7142bff0542d8a8f3859ffa184236 | | created_at | 2018-08-05 00:37:07.336918 | | updated_at | None | | cpu | 100 | | memory_size | 33554432 | +-------------+--------------------------------------------------------------+
Invoke the function by specifying the function name or ID.
$ openstack function execution create docker_test +------------------+--------------------------------------+ | Field | Value | +------------------+--------------------------------------+ | id | 8fe0e2e9-2133-4abb-8cd4-f2f14935cab4 | | function_id | 6fa6932d-ee43-41d4-891c-77a96b52c697 | | function_version | 0 | | description | None | | input | None | | result | {"duration": 3} | | status | success | | sync | True | | project_id | 6ae7142bff0542d8a8f3859ffa184236 | | created_at | 2018-08-05 00:37:25 | | updated_at | 2018-08-05 00:37:29 | +------------------+--------------------------------------+
Check the execution log.
$ openstack function execution log show 8fe0e2e9-2133-4abb-8cd4-f2f14935cab4 Hello Qinling
Config timeout for the function¶
In the cloud, you need to pay for the cloud resources that are used to run your Qinling function. To prevent your function from running indefinitely, you specify a timeout. When the specified timeout is reached, Qinling terminates execution of the function. We recommend you set this value based on your expected execution time. The default is 5 seconds and you can set it up to 300 seconds.
Note
This guide assumes you already have a Python2 or Python3 runtime available in the deployment
Create a Python function that simply sleeps for 10 seconds to simulate a long-running function.
mkdir ~/qinling_test && cd ~/qinling_test cat <<EOF > test_sleep.py import time def main(seconds=10, **kwargs): time.sleep(seconds) EOF
Create the Qinling function.
$ openstack function create --runtime $runtime_id --entry test_sleep.main --file ~/qinling_test/test_sleep.py --name test_sleep +-------------+-------------------------------------------------------------------------+ | Field | Value | +-------------+-------------------------------------------------------------------------+ | id | 6c2cb248-5065-4a0a-9b7a-06818693358c | | name | test_sleep | | description | None | | count | 0 | | code | {u'source': u'package', u'md5sum': u'c0830d40dbef48b11af9e63a653799ac'} | | runtime_id | ba429da0-b800-4f27-96ea-eb527bd68004 | | entry | test_sleep.main | | project_id | d256a42b9f8e4d66805d91655b36a318 | | created_at | 2018-09-10 01:43:06.250137 | | updated_at | None | | cpu | 100 | | memory_size | 33554432 | | timeout | 5 | +-------------+-------------------------------------------------------------------------+
Invoke the function. You will see the execution is terminated after about 5 seconds(the default timeout).
$ openstack function execution create test_sleep +------------------+--------------------------------------------------------------+ | Field | Value | +------------------+--------------------------------------------------------------+ | id | e096f4b3-85a7-4356-93e9-5f583e802aa2 | | function_id | 6c2cb248-5065-4a0a-9b7a-06818693358c | | function_version | 0 | | description | None | | input | None | | result | {"duration": 5.097, "output": "Function execution timeout."} | | status | failed | | sync | True | | project_id | d256a42b9f8e4d66805d91655b36a318 | | created_at | 2018-09-10 01:44:46 | | updated_at | 2018-09-10 01:44:55 | +------------------+--------------------------------------------------------------+
Update the function by setting a longer timeout value.
$ openstack function update test_sleep --timeout 15 +-------------+-------------------------------------------------------------------------+ | Field | Value | +-------------+-------------------------------------------------------------------------+ | id | 6c2cb248-5065-4a0a-9b7a-06818693358c | | name | test_sleep | | description | None | | count | 1 | | code | {u'source': u'package', u'md5sum': u'c0830d40dbef48b11af9e63a653799ac'} | | runtime_id | ba429da0-b800-4f27-96ea-eb527bd68004 | | entry | test_sleep.main | | project_id | d256a42b9f8e4d66805d91655b36a318 | | created_at | 2018-09-10 01:43:06 | | updated_at | 2018-09-10 02:01:38.510319 | | cpu | 100 | | memory_size | 33554432 | | timeout | 15 | +-------------+-------------------------------------------------------------------------+
Invoke the function again to verify the function is successfully executed.
$ openstack function execution create test_sleep +------------------+--------------------------------------+ | Field | Value | +------------------+--------------------------------------+ | id | 6dd91e1d-df91-4e19-92b6-3bec474ee09a | | function_id | 6c2cb248-5065-4a0a-9b7a-06818693358c | | function_version | 0 | | description | None | | input | None | | result | {"duration": 10.143, "output": null} | | status | success | | sync | True | | project_id | d256a42b9f8e4d66805d91655b36a318 | | created_at | 2018-09-10 02:03:56 | | updated_at | 2018-09-10 02:04:06 | +------------------+--------------------------------------+
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