Update getting starting page with a minimal example & link to flytesnacks

rsts/user/getting_started/create_first.rst

@@ -14,18 +14,15 @@ You can save some effort by cloning the ``flytesnacks`` repo, and re-initializin
   git init
   cd python
 
-now open the "Makefile" and change the first line to ``IMAGE_NAME=myflyteproject``
 
-Let's also remove the existing python task so we can write one from scratch. ::
-
-  rm single_step/edges.py
+Let's take a look at how easy it is to use Flyte by writing a task from scratch.
 
 Creating a Project
 ******************
 
 In Flyte, workflows are organized into namespaces called "Projects". When you register a workflow, it must be registered under a project.
 
-Lets create a new project called ``myflyteproject``. Use the project creation endpoint to create the new project ::
+For example, to create a new project called ``myflyteproject``: use the project creation endpoint to create the new project ::
 
   curl -X POST localhost:30081/api/v1/projects -d '{"project": {"id": "myflyteproject", "name": "myflyteproject"} }'
 
@@ -37,89 +34,61 @@ The most basic Flyte primitive is a "task". Flyte Tasks are units of work that c
 
 Start by creating a new file ::
 
-   mkdir -p workflows
-   touch workflows/first.py
 
-This directory has been marked in the `configuration file <https://github.com/lyft/flytesnacks/blob/764b82aca5701137ebc0eda4e818466e5acc9219/sandbox.config#L2>`_ as the location to look for workflows and tasks.  Begin by importing some of the libraries that we'll need for this example.
+   touch cookbook/recipes/core/first.py
+
 
 .. code-block:: python
 
-  from __future__ import absolute_import
-  from __future__ import division
-  from __future__ import print_function
-
-  import urllib.request as _request
+  from urllib import request
 
   import cv2
-  from flytekit.common import utils
-  from flytekit.sdk.tasks import python_task, outputs, inputs
-  from flytekit.sdk.types import Types
-  from flytekit.sdk.workflow import workflow_class, Output, Input
+  import flytekit
+  from flytekit import task, workflow
+  from flytekit.types.file import FlyteFile
 
-From there, we can begin to write our first task.  It should look something like this. 
+From there, we can begin to write our first task.  It should look something like this:
 
 .. code-block:: python
 
-  @inputs(image_location=Types.String)
-  @outputs(parsed_image=Types.Blob)
-  @python_task
-  def edge_detection_canny(wf_params, image_location, parsed_image):
-      with utils.AutoDeletingTempDir('test') as tmpdir:
-          plane_fname = '{}/plane.jpg'.format(tmpdir.name)
-          with _request.urlopen(image_location) as d, open(plane_fname, 'wb') as opfile:
-              data = d.read()
-              opfile.write(data)
-
-          img = cv2.imread(plane_fname, 0)
-          edges = cv2.Canny(img, 50, 200)  # hysteresis thresholds
-
-          output_file = '{}/output.jpg'.format(tmpdir.name)
-          cv2.imwrite(output_file, edges)
-
-          parsed_image.set(output_file)
+  @task
+  def edge_detection_canny(image_location:str) -> FlyteFile:
+      working_dir = flytekit.current_context().working_directory:
+      plane_fname = '{}/plane.jpg'.format(working_dir.name)
+      with request.urlopen(image_location) as d, open(plane_fname, 'wb') as opfile:
+          data = d.read()
+          opfile.write(data)
+
+      img = cv2.imread(plane_fname, 0)
+      edges = cv2.Canny(img, 50, 200)  # hysteresis thresholds
+
+      output_file = '{}/output.jpg'.format(working_dir.name)
+      cv2.imwrite(output_file, edges)
+
+      return FlyteFile["jpg"](path=output_file)
 
 
 Some of the new concepts demonstrated here are:
 
-* ``wf_params``: The first argument to a python task is a Flyte SDK defined object that offers handlers like logging.
-* Inputs and outputs are first defined in the decorator, and then passed into the argument of the function.  Note that the names in the function signature need to match those in the decorator arguments.
-* A ``Blob`` is a Flyte Kit type that represents binary data.  It is used to offload data to a storage location like S3.  Here we use it to store an image.
+* Use the ``@task`` decorator to convert your typed python function to a Flyte task.
+* A ``FlyteFile`` is a Flyte Kit type that represents binary data.  It is used to offload data to a storage location like S3.  Here we use it to store an image.
 
 Writing a Workflow
 *********************
 Next you need to call that task from a workflow.  In the same file, add these lines.
 
 .. code-block:: python
 
-  @workflow_class
-  class EdgeDetectorWf(object):
-      image_input = Input(Types.String, required=True, help="Image to run for")
-      run_edge_detection = edge_detection_canny(image_location=image_input)
-      edges = Output(run_edge_detection.outputs.parsed_image, sdk_type=Types.Blob)
-
+   @workflow
+   class EdgeDetectorWf(image_input: str) -> FlyteFile:
+       edges = edge_detection_canny(image_location=image_input)
+       return edges
+
 This code block creates a workflow, with one task. The workflow itself has an input (the link to an image) that gets passed into the task, and an output, which is the processed image.
 
+You can call this workflow ``EdgeDetectorWf(image_input=...)`` and iterate locally before moving on to register it with Flyte.
 
 Interacting with Flyte
 ************************
 
-Flyte fulfills tasks using docker images. You'll need to build a docker image from this code before it can run in Flyte. The repo has a make target to build the docker image for you ::
-
-  eval $(minikube -p minikube docker-env)  # If using the flyte sandbox via minikube
-  make docker_build
-
-If you have the flyte sandbox installed on your local machine, the image will be accessible to your Flyte system. If you're running a remote Flyte instance, you'll need to upload this image to a remote registry such as Dockerhub, Amazon ECR, or Google Container Registry, so that it can be used by the Flyte system.
-
-To upload to a remote registry (or even local registry), use ::
-
-  DOCKER_REGISTRY_USERNAME={username} DOCKER_REGISTRY_PASSWORD={pass} REGISTRY=docker.io make docker_build
-
-Replace the values above with your registry username, password, and registry endpoint.
-
-You may need to change the ``IMAGE_NAME`` in the Makefile to reflect your namespace in the docker registry. (ex ``{{my docker username}}/myflyteproject``)
-
-With the image built, we just need to register the tasks and workflows. The process is the same as what we had done previously. ::
-
-  docker run --network host -e FLYTE_PLATFORM_URL='127.0.0.1:30081' {{ your docker image }} pyflyte -p myflyteproject -d development -c sandbox.config register workflows
-
-After this, you should be able to visit the Flyte UI, and run the workflow as you did with ``flytesnacks`` previously.
+For detailed and interactive example workflow 'recipes' check out the `Flytesnacks Cookbook <https://flytecookbook.readthedocs.io/en/latest//>`_