app.py

# Copyright 2018 Markus Scheidgen
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an"AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
All APIs are served by one Flask app (:py:mod:`nomad.api.app`) under different paths.
"""

from flask import Flask, jsonify
from flask_restplus import Api
from flask_cors import CORS
from werkzeug.exceptions import HTTPException
from werkzeug.wsgi import DispatcherMiddleware
import os.path
import inspect

from nomad import config, utils

base_path = config.services.api_base_path
""" Provides the root path of the nomad APIs. """

app = Flask(
    __name__,
    static_url_path='/docs',
    static_folder=os.path.abspath(os.path.join(os.path.dirname(__file__), '../../docs/.build/html')))
""" The Flask app that serves all APIs. """

app.config.setdefault('APPLICATION_ROOT', base_path)
app.config.setdefault('RESTPLUS_MASK_HEADER', False)
app.config.setdefault('RESTPLUS_MASK_SWAGGER', False)


def api_base_path_response(env, resp):
    resp(b'200 OK', [(b'Content-Type', b'text/plain')])
    return [
        ('Development nomad api server. Api is served under %s/.' %
            config.services.api_base_path).encode('utf-8')]


app.wsgi_app = DispatcherMiddleware(
    api_base_path_response, {config.services.api_base_path: app.wsgi_app})


CORS(app)

api = Api(
    app, version='1.0', title='nomad@FAIRDI API',
    description='Official API for nomad@FAIRDI services.',
    validate=True)
""" Provides the flask restplust api instance """


@app.errorhandler(Exception)
@api.errorhandler
def handle(error: Exception):
    status_code = getattr(error, 'code', 500)
    name = getattr(error, 'name', 'Internal Server Error')
    description = getattr(error, 'description', 'No description available')
    data = dict(
        code=status_code,
        name=name,
        description=description)
    data.update(getattr(error, 'data', []))
    response = jsonify(data)
    response.status_code = status_code
    if status_code == 500:
        utils.get_logger(__name__).error('internal server error', exc_info=error)
    return response


def with_logger(func):
    """
    Decorator for endpoint implementations that provides a pre configured logger and
    automatically logs errors on all 500 responses.
    """
    signature = inspect.signature(func)
    has_logger = 'logger' in signature.parameters
    wrapper_signature = signature.replace(parameters=tuple(
        param for param in signature.parameters.values()
        if param.name != 'logger'
    ))

    def wrapper(*args, **kwargs):
        if has_logger:
            args = inspect.getcallargs(wrapper, *args, **kwargs)
            logger_args = {
                k: v for k, v in args.items()
                if k in ['upload_id', 'calc_id']}
            logger = utils.get_logger(__name__, **logger_args)
            args.update(logger=logger)
        try:
            return func(**args)
        except HTTPException as e:
            if getattr(e, 'code', None) == 500:
                logger.error('Internal server error', exc_info=e)
            raise e
        except Exception as e:
            logger.error('Internal server error', exc_info=e)
            raise e

    wrapper.__signature__ = wrapper_signature
    return wrapper