Building Python runtime locally

Pre-requisites

Docker
curl, wget, or Postman

Clone repo

git clone https://github.com/apache/openwhisk-runtime-python
cd openwhisk-runtime-python

Build the docker image

Build docker image using Python 3.11 (recommended). This tutorial assumes you're building with python 3.11. Run local_build.sh to build docker. This script takes two parameters as input

-r Specific runtime image folder name to be built, it can be one of python39Action, python310Action, or python311Action
-t The name for docker image and tag used for building the docker image. Example: action-python-v3.11:1.0-SNAPSHOT

cd tutorials
chmod 755 local_build.sh
cd ..
./tutorials/local_build.sh -r python311Action -t action-python-v3.11:1.0-SNAPSHOT

Verify docker image

Check docker IMAGE ID (3rd column) for repository action-python-v3.11

docker images

If the local_build.sh script is sucessful, you should see an image that looks something like:

action-python-v3.11         1.0-SNAPSHOT ...

(Optional) Tag docker image

This is required if you’re pushing your docker image to a registry e.g. dockerHub

docker tag <docker_image_ID> <dockerHub_username>/action-python-v3.11:1.0-SNAPSHOT

Run docker image

Run docker on localhost with either the following commands:

docker run -p 127.0.0.1:80:8080/tcp --name=bloom_whisker --rm -it action-python-v3.11:1.0-SNAPSHOT

Or run the container in the background (Add -d (detached) to the command above)

docker run -d -p 127.0.0.1:80:8080/tcp --name=bloom_whisker --rm -it action-python-v3.11:1.0-SNAPSHOT

Note: If you run your docker container in the background you'll want to stop it with:

docker stop <container_id>

Where <container_id> is obtained from docker ps command bellow

List all running containers

docker ps

or

docker ps -a

You should see a container named bloom_whisker being run and a <container_id> associated with it in the first column.

Test docker image

Docker image can be tested by creating functions. This documents lists creating three types of functions

Functions without arguments
Functions with arguments
Advanced functions

Functions without arguments

Create function

Create a function (Each container can only hold one function). In this first example we'll be creating a very simple Helloworld function. Create a json file called python-data-init-run.json which will contain the function that looks something like the following:

NOTE: value of code is the actual payload and must match the syntax of the target runtime language, in this case python

{
   "value": {
      "name" : "python-helloworld",
      "main" : "main",
      "binary" : false,
      "code" : "def main(args): return {'payload': 'Hello World!'}"
   }
}

Test function

Initialize function

To issue the action against the running runtime, we must first make a request against the init API We need to issue POST requests to init our function This step can be run using either curl, wget, or Postman

Using curl

The option -d signifies we're issuing a POST request in curl

curl -d "@python-data-init-run.json" -H "Content-Type: application/json" http://localhost/init

Using wget

The option --post-file signifies we're issuing a POST request in wget

wget --post-file=python-data-init-run.json --header="Content-Type: application/json" http://localhost/init

Using postman

The above can also be achieved with Postman by setting the headers and body accordingly

Expected response of Initialize function step

Clientresponse should be as below

{"ok":true}

Server will remain silent in this case

Run function

Now we can invoke/run our function agains the run API with:

Using curl

POST request

curl -d "@python-data-init-run.json" -H "Content-Type: application/json" http://localhost/run

GET request

curl --data-binary "@python-data-init-run.json" -H "Content-Type: application/json" http://localhost/run

Using wget

POST request

The -O- is to redirect wget response to stdout.

wget -O- --post-file=python-data-init-run.json --header="Content-Type: application/json" http://localhost/run

GET request

wget -O- --body-file=python-data-init-run.json --method=GET --header="Content-Type: application/json" http://localhost/run

Using postman

The above can also be achieved with Postman by setting the headers and body accordingly.

(Recommended) Run function

The same file python-data-init-run.json from function initialization request is used to trigger(run) the function. It is not necessary nor recommended. To trigger a function we only need to pass the parameters of the function. Hence, instead in the above example, it is prefered to create a file called python-data-params.json that looks like the following:

{
   "value": {}
}

And trigger/run the function with the following:

curl --data-binary "@python-data-params.json" -H "Content-Type: application/json" http://localhost/run

This also works with wget and postman equivalents. Make sure you have the correct request type set and the respective body. Also set the correct headers key value pairs, which for us is "Content-Type: application/json"

Expected response of Run function step

After you trigger the function with one of the above commands you should expect the following client response:

{"payload": "Hello World!"}

And Server expected response:

XXX_THE_END_OF_A_WHISK_ACTIVATION_XXX
XXX_THE_END_OF_A_WHISK_ACTIVATION_XXX

Functions with arguments

Create function

Note: If your container still running from the previuous example you must stop it and re-run it before proceding. Remember that each python runtime can only hold one function (which cannot be overrided due to security reasons).

Create a json file called python-data-init-params.json which will contain the function to be initialized that looks like the following:

{
   "value": {
      "name": "python-helloworld-with-params",
      "main" : "main",
      "binary" : false,
      "code" : "def main(args): return {'payload': 'Hello ' + args.get('name') + ' from ' + args.get('place') + '!!!'}"
   }
}

Also create a json file python-data-run-params.json which will contain the parameters to the function used to trigger it. Notice here we're creating 2 separate file from the beginning since this is good practice to make the disticntion between what needs to be send via the init API and what needs to be sent via the run API:

{
   "value": {
      "name": "UFO",
      "place": "Mars"
   }
}

Test function

Initialize function

To initialize the function make sure the python runtime container is running. If not, spin the container by following Run docker image step. Issue a POST request against the init API with the following command:

Using curl

curl -d "@python-data-init-params.json" -H "Content-Type: application/json" http://localhost/init

Using wget

wget --post-file=python-data-init-params.json --header="Content-Type: application/json" http://localhost/init

Using postman

The above can also be achieved with Postman by setting the headers and body accordingly

Expected response of Initialize function

Client response should be as below

{"ok":true}

Server will remain silent in this case

Run function

To run/trigger the function issue requests against the run API with the following command:

Using curl

POST request

curl -d "@python-data-run-params.json" -H "Content-Type: application/json" http://localhost/run

GET request

curl --data-binary "@python-data-run-params.json" -H "Content-Type: application/json" http://localhost/run

Using wget

POST request

The -O- is to redirect wget response to stdout.

wget -O- --post-file=python-data-run-params.json --header="Content-Type: application/json" http://localhost/run

GET request

wget -O- --body-file=python-data-run-params.json --method=GET --header="Content-Type: application/json" http://localhost/run

Using postman

The above can also be achieved with Postman by setting the headers and body accordingly.

Expected response of Run function step

After you trigger the function with one of the above commands you should expect the following client response:

{"payload": "Hello UFO from Mars!!!"}

And Server expected response:

XXX_THE_END_OF_A_WHISK_ACTIVATION_XXX
XXX_THE_END_OF_A_WHISK_ACTIVATION_XXX

Advanced functions

Create function

This function will calculate the nth Fibonacci number. It calculates the nth number of the Fibonacci sequence recursively in O(n) time.

def fibonacci(n, mem):
   if (n == 0 or n == 1):
      return 1
   if (mem[n] == -1):
      mem[n] = fibonacci(n-1, mem) + fibonacci(n-2, mem)
   return mem[n]

def main(args):
   n = int(args.get('fib_n'))
   mem = [-1 for i in range(n+1)]
   result = fibonacci(n, mem)
   key = 'Fibonacci of n == ' + str(n)
   return {key: result}

Create a json file called python-fib-init.json to initialize our fibonacci function and insert the following. (It’s the same code as above but since we can’t have a string span multiple lines in JSON we need to put all this code in one line and this is how we do it. It’s ugly but not much we can do here)

{
   "value": {
      "name": "python-recursive-fibonacci",
      "main" : "main",
      "binary" : false,
      "code" : "def fibonacci(n, mem):\n\tif (n == 0 or n == 1):\n\t\treturn 1\n\tif (mem[n] == -1):\n\t\tmem[n] = fibonacci(n-1, mem) + fibonacci(n-2, mem)\n\treturn mem[n]\n\ndef main(args):\n\tn = int(args.get('fib_n'))\n\tmem = [-1 for i in range(n+1)]\n\tresult = fibonacci(n, mem)\n\tkey = 'Fibonacci of n == ' + str(n)\n\treturn {key: result}"
   }
}

Create a json file called python-fib-run.json which will be used to run/trigger our function with the appropriate argument:

{
   "value": {
      "fib_n": "40"
   }
}

Test function

Initialize function

To initialize the function make sure the python runtime container is running. If not, spin the container by following Run docker image step. Initialize our fibonacci function by issuing a POST request against the init API with the following command:

Using curl

curl -d "@python-fib-init.json" -H "Content-Type: application/json" http://localhost/init

Using wget

wget --post-file=python-fib-init.json --header="Content-Type: application/json" http://localhost/init

Using postman

The above can also be achieved with Postman by setting the headers and body accordingly

Expected response of Initialize function

Client response should be as below

{"ok":true}

You've noticed by now that init API always returns {"ok":true} for a successful initialized function. And the server, again, will remain silent

Run function

Trigger/run the function with a request against the run API with the following command:

Using curl

POST request

curl -d "@python-fib-run.json" -H "Content-Type: application/json" http://localhost/run

GET request

curl --data-binary "@python-fib-run.json" -H "Content-Type: application/json" http://localhost/run

Using wget

POST request

The -O- is to redirect wget response to stdout.

wget -O- --post-file=python-fib-run.json --header="Content-Type: application/json" http://localhost/run

GET request

wget -O- --body-file=python-fib-run.json --method=GET --header="Content-Type: application/json" http://localhost/run

Using postman

The above can also be achieved with Postman by setting the headers and body accordingly.

Expected response of Run function step

After you trigger the function with one of the above commands you should expect the following client response:

{"Fibonacci of n == 40": 165580141}

And Server expected response:

XXX_THE_END_OF_A_WHISK_ACTIVATION_XXX
XXX_THE_END_OF_A_WHISK_ACTIVATION_XXX

Additonal testing

Yyou can edit python-fib-run.json and try other fib_n values. Save python-fib-run.json and trigger the function again. Notice that here we're just modifying the parameters of our function; therefore, there's no need to re-run/re-initialize our container that contains our Python runtime.
You can also automate most of this process through docker actions by using invoke.py

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local_build.md

local_build.md

Building Python runtime locally

Pre-requisites

Clone repo

Build the docker image

Verify docker image

(Optional) Tag docker image

Run docker image

Test docker image

Functions without arguments

Create function

Test function

Initialize function

Expected response of Initialize function step

Run function

(Recommended) Run function

Expected response of Run function step

Functions with arguments

Create function

Test function

Initialize function

Expected response of Initialize function

Run function

Expected response of Run function step

Advanced functions

Create function

Test function

Initialize function

Expected response of Initialize function

Run function

Expected response of Run function step

Additonal testing

Files

local_build.md

Latest commit

History

local_build.md

File metadata and controls

Building Python runtime locally

Pre-requisites

Clone repo

Build the docker image

Verify docker image

(Optional) Tag docker image

Run docker image

Test docker image

Functions without arguments

Create function

Test function

Initialize function

Expected response of Initialize function step

Run function

(Recommended) Run function

Expected response of Run function step

Functions with arguments

Create function

Test function

Initialize function

Expected response of Initialize function

Run function

Expected response of Run function step

Advanced functions

Create function

Test function

Initialize function

Expected response of Initialize function

Run function

Expected response of Run function step

Additonal testing