Re-write simple sample app using connexion

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/.dockerignore

@@ -0,0 +1 @@
+__pycache__/

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/Dockerfile.{{cookiecutter.PROJECT_NAME_SLUG}}

@@ -1,24 +1,37 @@
-ARG PYTHON_VERSION=3.7.0-alpine3.8
+ARG PYTHON_VERSION=3.7
 
-FROM python:${PYTHON_VERSION} as builder
+FROM python:${PYTHON_VERSION} AS builder
 
-WORKDIR /usr/src/{{cookiecutter.PROJECT_NAME_SLUG}}
+WORKDIR /src
+
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+RUN pip wheel --no-cache-dir -r requirements.txt -w /deps
 
 COPY requirements-dev.txt .
 RUN pip install --no-cache-dir -r requirements-dev.txt
 
 COPY . .
 
-# Run tests, linter
-RUN pytest testapp.py \
+RUN flake8 *.py \
  && isort --check-only *.py \
- && flake8 *.py
+ && pydocstyle *.py \
+ && python -m doctest *.py
+
+FROM python:${PYTHON_VERSION}-slim AS runtime
+
+WORKDIR /{{cookiecutter.PROJECT_NAME_SLUG}}/deps
+COPY --from=builder /deps .
+RUN pip install --no-cache-dir *.whl
+
+WORKDIR /{{cookiecutter.PROJECT_NAME_SLUG}}/src
+COPY --from=builder /src .
 
-# Release
-FROM python:${PYTHON_VERSION}
+ENV HOST=0.0.0.0
+ENV PORT=80
+ENV WORKERS=4
+ENV LOG_LEVEL=info
 
-WORKDIR /{{cookiecutter.PROJECT_NAME_SLUG}}
-COPY --from=builder /usr/src/{{cookiecutter.PROJECT_NAME_SLUG}} /{{cookiecutter.PROJECT_NAME_SLUG}}
-RUN pip install -r requirements.txt
+EXPOSE $PORT
 
-CMD ["python", "main.py"]
+CMD gunicorn --log-level="$LOG_LEVEL" --bind="$HOST:$PORT" --workers="$WORKERS" "main:build_app(wsgi=True)"

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/api.spec.yaml

@@ -0,0 +1,32 @@
+swagger: '2.0'
+
+info:
+  title: Transformation API
+  version: '1.0'
+
+basePath: '/'
+
+paths:
+  '/':
+    post:
+      summary: Transform the data.
+      operationId: main.main
+      consumes:
+        - application/json
+      parameters:
+        - $ref: '#/parameters/Data'
+      responses:
+        200:
+          description: The transformed data.
+
+parameters:
+  Data:
+    name: data
+    description: The data to transform.
+    in: body
+    schema:
+      $ref: '#/definitions/Data'
+    required: true
+
+definitions:
+{{DATA_SCHEMA}}

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/data.spec.yaml

@@ -0,0 +1,11 @@
+Data:
+  properties:
+    key:
+      description: The key of the input.
+      type: string
+    intValue:
+      description: The value of the input.
+      type: number
+  required:
+    - key
+    - intValue

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/logic.py

@@ -0,0 +1,24 @@
+"""
+Implements the business logic for {{cookiecutter.PROJECT_NAME_SLUG}}.
+
+Overwrite the sample implementation in this file with your own requirements.
+The framework expects a function named `transform` to be present in this
+module but helper functions may be added at your convenience.
+"""
+
+
+def transform(data: dict) -> dict:
+    """
+    Apply the required transformations to the input data.
+
+    The input data for this function is guaranteed to follow the specification
+    provided to the framework. Consult `data.spec.yaml` for an example.
+
+    Args:
+      data: input object to transform
+
+    >>> transform({'intValue': 100})
+    {'intValue': 200}
+    """
+    data['intValue'] += 100
+    return data

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/main.py

@@ -1,94 +1,77 @@
-""" Entrypoint for customer application. Listens for HTTP requests from
-the input reader, and sends the transformed message to the output writer. """
-import json
-import logging
-import os
-from http.server import BaseHTTPRequestHandler
-from http.server import HTTPServer
-
-import requests
-
-import datahelper
-
-# HOST & PORT are the values used to run the current application
-HOST = os.getenv("HOST")
-PORT = os.getenv("PORT")
-
-# OUTPUT_URL is the url which receives all the output messages after they are processed by the app
-OUTPUT_URL = os.getenv("OUTPUT_URL")
-
-# Filepath for the JSON schema which represents
-# the schema for the expected input messages to the app
-SCHEMA_FILEPATH = os.getenv("SCHEMA_FILEPATH")
-
-
-class Socket(BaseHTTPRequestHandler):
-    """Handles HTTP requests that come to the server."""
-
-    def _set_headers(self):
-        """Sets common headers when returning an OK HTTPStatus. """
-        self.send_response(200)
-        self.send_header('Content-type', 'text/html')
-        self.end_headers()
-
-    def do_POST(self):
-        """Handles a POST request to the server.
-        Sends 400 error if there is an issue, otherwise sends a success message.
-
-        Raises:
-          ValidationError: Returns when data given is not valid against schema
-          HTTPError: Returns when there is an error sending message to output url
-
-        """
-        content_length = int(self.headers['Content-Length'])
-        data = self.rfile.read(content_length)
-        data = data.decode("utf-8")
-
-        try:
-            datahelper.validate_schema(data, SCHEMA_FILEPATH)
-        except BaseException:
-            self.send_error(
-                400, 'Incorrect data format. Please check JSON schema.')
-            logging.error('Incorrect data format. Please check JSON schema.')
-            raise
-
-        try:
-            transformed_data = datahelper.transform(data)
-            output_message(transformed_data)
-            self._set_headers()
-            self.wfile.write(bytes("Data successfully consumed", 'utf8'))
-        except BaseException:
-            self.send_error(400, 'Error when sending output message')
-            logging.error('Error when sending output message')
-            raise
-
-
-def output_message(data: object):
-    """Outputs the transformed payload to the specified HTTP endpoint
-
-    Args:
-      data: transformed json object to send to output writer
-    """
-    request = requests.post(OUTPUT_URL, data=json.dumps(data))
-    if request.status_code != 200:
-
-        logging.error("Error with a request %s and message not sent was %s",
-                      request.status_code, data)
-    else:
-        logging.info("%s Response received from output writer",
-                     request.status_code)
+"""
+Entrypoint for customer application.
+
+Listens for HTTP(S) requests from the input reader, transforms the message
+and sends the transformed message to the output writer.
+
+You can view a specification for the API at /swagger.json as well as a testing
+console at /ui/.
+
+All business logic for {{cookiecutter.PROJECT_NAME_SLUG}} should be included
+in `logic.py` and it is unlikely that changes to this `main.py` file will be
+required.
+"""
+from logging import getLogger
+
+from requests import post
+
+import settings
+from logic import transform
+
+LOG = getLogger(__name__)
+
+
+def main(data: dict):
+    """Transform the input and forward the transformed payload via HTTP(S)."""
+    data = transform(data)
+
+    if not settings.OUTPUT_URL:
+        LOG.warning('Not OUTPUT_URL specified, not forwarding data.')
+        return data, 500
+
+    response = post(settings.OUTPUT_URL, json=data)
+    if not response.ok:
+        LOG.error('Error %d with post to url %s and body %s.',
+                  response.status_code, settings.OUTPUT_URL, data)
+        return data, response.status_code
 
+    LOG.info('Response %d received from output writer.', response.status_code)
+    return data, 200
 
-def run(server_class=HTTPServer, handler_class=Socket):
-    """Run the server on specified host and port, using our
-    custom Socket class to receive and process requests.
-    """
 
-    server_address = (HOST, int(PORT))
-    httpd = server_class(server_address, handler_class)
-    logging.info('Running server on host ${HOST} and port ${PORT}')
-    httpd.serve_forever()
+def build_app(wsgi=False):
+    """Create the web server."""
+    from connexion import App
+
+    with open(settings.DATA_SCHEMA, encoding='utf-8') as fobj:
+        data_schema = '\n'.join('  {}'.format(line.rstrip('\r\n'))
+                                for line in fobj)
+
+    LOG.setLevel(settings.LOG_LEVEL)
+
+    app = App(__name__)
+    app.add_api('api.spec.yaml', arguments={'DATA_SCHEMA': data_schema})
+
+    return app.app if wsgi else app
+
+
+def cli():
+    """Command line interface for the web server."""
+    from argparse import ArgumentParser
+
+    from yaml import YAMLError
+
+    parser = ArgumentParser(description=__doc__)
+    parser.parse_args()
+
+    try:
+        app = build_app()
+    except YAMLError as ex:
+        parser.error('Unable to parse {} as a Swagger spec.\n\n{}'
+                     .format(settings.DATA_SCHEMA, ex))
+    else:
+        app.run(port=settings.PORT, host=settings.HOST)
 
 
 if __name__ == "__main__":
-    run()
+    cli()

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/requirements-dev.txt

@@ -1,7 +1,3 @@
-hypothesis
-python-dotenv
-jsonschema
-pytest
 flake8
 isort
-requests
+pydocstyle

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/requirements.txt

@@ -1,3 +1,4 @@
-python-dotenv
-jsonschema
+connexion[swagger-ui]
+environs
+gunicorn
 requests

agogosml_cli/cli/templates/apps/simple/{{cookiecutter.PROJECT_NAME_SLUG}}/settings.py

@@ -0,0 +1,15 @@
+"""
+Module to hold all application configuration.
+
+All environment variable access hould happen in this module only.
+"""
+from environs import Env
+
+env = Env()
+env.read_env()
+
+PORT = env.int('PORT', 8888)
+HOST = env('HOST', '127.0.0.1')
+DATA_SCHEMA = env('SCHEMA_FILEPATH', 'data.spec.yaml')
+OUTPUT_URL = env('OUTPUT_URL', '')
+LOG_LEVEL = env('LOG_LEVEL', 'INFO').upper()