Flask App factory PR #1

.flaskenv

@@ -14,5 +14,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-FLASK_APP=superset:app
-FLASK_ENV=development
+FLASK_APP="superset.app:create_app()"
+FLASK_ENV="development"

requirements-dev.txt

@@ -17,6 +17,7 @@
 black==19.3b0
 coverage==4.5.3
 flask-cors==3.0.7
+flask-testing==0.7.1
 ipdb==0.12
 isort==4.3.21
 mypy==0.670

setup.py

@@ -128,4 +128,5 @@ def get_git_sha():
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
     ],
+    tests_require=["flask-testing==0.7.1"],
 )

superset/__init__.py

@@ -14,229 +14,38 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-# pylint: disable=C,R,W
 """Package's main module!"""
-import json
-import logging
-import os
-from copy import deepcopy
-from typing import Any, Dict
+from flask import current_app, Flask
+from werkzeug.local import LocalProxy
 
-import wtforms_json
-from flask import Flask, redirect
-from flask_appbuilder import AppBuilder, IndexView, SQLA
-from flask_appbuilder.baseviews import expose
-from flask_compress import Compress
-from flask_migrate import Migrate
-from flask_talisman import Talisman
-from flask_wtf.csrf import CSRFProtect
-
-from superset import config
+from superset.app import create_app
 from superset.connectors.connector_registry import ConnectorRegistry
+from superset.extensions import (
+    appbuilder,
+    cache_manager,
+    db,
+    event_logger,
+    feature_flag_manager,
+    manifest_processor,
+    results_backend_manager,
+    security_manager,
+    talisman,
+)
 from superset.security import SupersetSecurityManager
-from superset.utils.core import pessimistic_connection_handling, setup_cache
-from superset.utils.log import get_event_logger_from_cfg_value
-
-wtforms_json.init()
-
-APP_DIR = os.path.dirname(__file__)
-CONFIG_MODULE = os.environ.get("SUPERSET_CONFIG", "superset.config")
-
-if not os.path.exists(config.DATA_DIR):
-    os.makedirs(config.DATA_DIR)
-
-app = Flask(__name__)
-app.config.from_object(CONFIG_MODULE)  # type: ignore
-conf = app.config
-
-#################################################################
-# Handling manifest file logic at app start
-#################################################################
-MANIFEST_FILE = APP_DIR + "/static/assets/dist/manifest.json"
-manifest: Dict[Any, Any] = {}
-
-
-def parse_manifest_json():
-    global manifest
-    try:
-        with open(MANIFEST_FILE, "r") as f:
-            # the manifest inclues non-entry files
-            # we only need entries in templates
-            full_manifest = json.load(f)
-            manifest = full_manifest.get("entrypoints", {})
-    except Exception:
-        pass
-
-
-def get_js_manifest_files(filename):
-    if app.debug:
-        parse_manifest_json()
-    entry_files = manifest.get(filename, {})
-    return entry_files.get("js", [])
-
-
-def get_css_manifest_files(filename):
-    if app.debug:
-        parse_manifest_json()
-    entry_files = manifest.get(filename, {})
-    return entry_files.get("css", [])
-
-
-def get_unloaded_chunks(files, loaded_chunks):
-    filtered_files = [f for f in files if f not in loaded_chunks]
-    for f in filtered_files:
-        loaded_chunks.add(f)
-    return filtered_files
-
-
-parse_manifest_json()
-
-
-@app.context_processor
-def get_manifest():
-    return dict(
-        loaded_chunks=set(),
-        get_unloaded_chunks=get_unloaded_chunks,
-        js_manifest=get_js_manifest_files,
-        css_manifest=get_css_manifest_files,
-    )
-
-
-#################################################################
-
-for bp in conf["BLUEPRINTS"]:
-    try:
-        print("Registering blueprint: '{}'".format(bp.name))
-        app.register_blueprint(bp)
-    except Exception as e:
-        print("blueprint registration failed")
-        logging.exception(e)
-
-if conf.get("SILENCE_FAB"):
-    logging.getLogger("flask_appbuilder").setLevel(logging.ERROR)
-
-db = SQLA(app)
-
-if conf.get("WTF_CSRF_ENABLED"):
-    csrf = CSRFProtect(app)
-    csrf_exempt_list = conf.get("WTF_CSRF_EXEMPT_LIST", [])
-    for ex in csrf_exempt_list:
-        csrf.exempt(ex)
-
-pessimistic_connection_handling(db.engine)
-
-cache = setup_cache(app, conf.get("CACHE_CONFIG"))
-tables_cache = setup_cache(app, conf.get("TABLE_NAMES_CACHE_CONFIG"))
-
-migrate = Migrate(app, db, directory=APP_DIR + "/migrations")
-
-app.config["LOGGING_CONFIGURATOR"].configure_logging(app.config, app.debug)
-
-if app.config["ENABLE_CORS"]:
-    from flask_cors import CORS
-
-    CORS(app, **app.config["CORS_OPTIONS"])
-
-if app.config["ENABLE_PROXY_FIX"]:
-    from werkzeug.middleware.proxy_fix import ProxyFix
-
-    app.wsgi_app = ProxyFix(  # type: ignore
-        app.wsgi_app, **app.config["PROXY_FIX_CONFIG"]
-    )
-
-if app.config["ENABLE_CHUNK_ENCODING"]:
-
-    class ChunkedEncodingFix(object):
-        def __init__(self, app):
-            self.app = app
-
-        def __call__(self, environ, start_response):
-            # Setting wsgi.input_terminated tells werkzeug.wsgi to ignore
-            # content-length and read the stream till the end.
-            if environ.get("HTTP_TRANSFER_ENCODING", "").lower() == u"chunked":
-                environ["wsgi.input_terminated"] = True
-            return self.app(environ, start_response)
-
-    app.wsgi_app = ChunkedEncodingFix(app.wsgi_app)  # type: ignore
-
-if app.config["UPLOAD_FOLDER"]:
-    try:
-        os.makedirs(app.config["UPLOAD_FOLDER"])
-    except OSError:
-        pass
-
-for middleware in app.config["ADDITIONAL_MIDDLEWARE"]:
-    app.wsgi_app = middleware(app.wsgi_app)  # type: ignore
-
-
-class MyIndexView(IndexView):
-    @expose("/")
-    def index(self):
-        return redirect("/superset/welcome")
-
-
-custom_sm = app.config["CUSTOM_SECURITY_MANAGER"] or SupersetSecurityManager
-if not issubclass(custom_sm, SupersetSecurityManager):
-    raise Exception(
-        """Your CUSTOM_SECURITY_MANAGER must now extend SupersetSecurityManager,
-         not FAB's security manager.
-         See [4565] in UPDATING.md"""
-    )
-
-with app.app_context():
-    appbuilder = AppBuilder(
-        app,
-        db.session,
-        base_template="superset/base.html",
-        indexview=MyIndexView,
-        security_manager_class=custom_sm,
-        update_perms=False,  # Run `superset init` to update FAB's perms
-    )
-
-security_manager = appbuilder.sm
-
-results_backend = app.config["RESULTS_BACKEND"]
-results_backend_use_msgpack = app.config["RESULTS_BACKEND_USE_MSGPACK"]
-
-# Merge user defined feature flags with default feature flags
-_feature_flags = app.config["DEFAULT_FEATURE_FLAGS"]
-_feature_flags.update(app.config["FEATURE_FLAGS"])
-
-# Event Logger
-event_logger = get_event_logger_from_cfg_value(app.config["EVENT_LOGGER"])
-
-
-def get_feature_flags():
-    GET_FEATURE_FLAGS_FUNC = app.config["GET_FEATURE_FLAGS_FUNC"]
-    if GET_FEATURE_FLAGS_FUNC:
-        return GET_FEATURE_FLAGS_FUNC(deepcopy(_feature_flags))
-    return _feature_flags
-
-
-def is_feature_enabled(feature):
-    """Utility function for checking whether a feature is turned on"""
-    return get_feature_flags().get(feature)
-
-
-# Flask-Compress
-if conf.get("ENABLE_FLASK_COMPRESS"):
-    Compress(app)
-
-
-talisman = Talisman()
-
-if app.config["TALISMAN_ENABLED"]:
-    talisman.init_app(app, **app.config["TALISMAN_CONFIG"])
-
-# Hook that provides administrators a handle on the Flask APP
-# after initialization
-flask_app_mutator = app.config["FLASK_APP_MUTATOR"]
-if flask_app_mutator:
-    flask_app_mutator(app)
-
-from superset import views  # noqa isort:skip
-
-# Registering sources
-module_datasource_map = app.config["DEFAULT_MODULE_DS_MAP"]
-module_datasource_map.update(app.config["ADDITIONAL_MODULE_DS_MAP"])
-ConnectorRegistry.register_sources(module_datasource_map)
+from superset.utils.log import DBEventLogger, get_event_logger_from_cfg_value
+
+#  All of the fields located here should be considered legacy. The correct way
+#  to declare "global" dependencies is to define it in extensions.py,
+#  then initialize it in app.create_app(). These fields will be removed
+#  in subsequent PRs as things are migrated towards the factory pattern
+app: Flask = current_app
+cache = LocalProxy(lambda: cache_manager.cache)
+conf = LocalProxy(lambda: current_app.config)
+get_feature_flags = feature_flag_manager.get_feature_flags
+get_css_manifest_files = manifest_processor.get_css_manifest_files
+is_feature_enabled = feature_flag_manager.is_feature_enabled
+results_backend = LocalProxy(lambda: results_backend_manager.results_backend)
+results_backend_use_msgpack = LocalProxy(
+    lambda: results_backend_manager.should_use_msgpack
+)
+tables_cache = LocalProxy(lambda: cache_manager.tables_cache)