Building tasks

This guide will walk you through the development of a task container that a task developer can upload. Example tasks are provided in example tasks README. Each folder must contain all of the files listed in the structure below.

Each folder must contain all of the files listed in the structure as follows:

- folder
  - Dockerfile
  - src
  - description.txt
  - name.txt
  - example_input.bin
  - example_output.bin
  - config.json

Building a task container

1. App that handles requests

The app will receive a post request at localhost:8080\ and return the result. The input format is any json object and the output format is a string. After the app starts up, print "meca-init-done".

For example, we create a flask app:

  from flask import Flask, request
  import json

  app = Flask(__name__)

  @app.route('/', methods=['POST'])
  def hello_world():
      data = request.json
      return data['input']

  print("meca-init-done")

2. Dockerfile

Expose port 8080 to the app of the request handler.

Following the flask app created above, the Dockerfile may look like this:

FROM python:3.9-slim

WORKDIR /app

COPY flask_app.py flask_app.py

EXPOSE 8080

CMD ["python", "-m", "flask", "--app", "flask_app.py", "run", "--host=0.0.0.0", "--port=8080"]

3. config.json fields

The config.json file contains the configuration of the task, which it will use to build its container, with the following default fields:

DEFAULTS:

{
  "resource": {
    "cpu": 1,
    "mem": 128,
    "use_gpu": false,
    "gpu_count": 0
  }
}

field	description
`resource.cpu`	The number of CPUs to allocate to the task. This field will limit the users that can run the task to those with the same or more CPUs available.
`resource.mem`	The amount of memory to allocate to the task in MB. This field will limit the users that can run the task to those with the same or more memory available.
`resource.use_gpu`	Whether the task requires a GPU to run.
`resource.gpu_count`	The number of GPUs to allocate to the task, if `use_gpu` is true.

4. Describe your task

Fill in the description.txt and name.txt files with the description and name of your task. In the example_input.bin and example_output.bin files, provide examples of the input and output of your task exactly as they are read in the body of a HTTP request and reply.

5. Using and uploading the container

Build the image and push it to IPFS via the MECAnywhere CLI as a task developer. You will be compensated with the task fee that you list for each task executed by a MECAnywhere client.

Test your task folder structure by running the test function in the MECAnywhere CLI.