Adding support for configuration via environment variables

src/application.py

@@ -15,16 +15,11 @@
     You should have received a copy of the GNU General Public License
     along with scoreboard-benchmark .  If not, see <http://www.gnu.org/licenses/>.
 """
-try:  # This is mainly required for Travis CI automated testing.
 from src.config import config
-except ImportError:
-    from src.config_lock import config
-
 from src.models import db
 from src.views.errors import error_pages
 from src.views.scoreboard import scoreboard
-from src.resources.utilities import cache
-import os
+from src.resources.utilities import cache, get_env_variable
 import flask_bootstrap
 import flask
 
@@ -42,13 +37,10 @@ def create_app(config_name):
 
     return app
 
-try:
-    configuration = os.environ['BSFLASK_ENV']
-    print("Running with configuration: " + configuration)
+configuration = get_env_variable("BSFLASK_ENV", fallback="default")
 app = create_app(configuration)
-except (IndexError, KeyError):
-    print("Using default configuration.")
-    app = create_app('default')
+print("Running with", configuration, "configuration setting.")
+
 
 
 if __name__ == "__main__":

src/config.py

@@ -17,6 +17,7 @@
 """
 import os
 from src.models import db
+from src.resources.utilities import get_env_variable
 
 basedir = os.path.abspath(os.path.dirname(__file__))
 
@@ -61,10 +62,10 @@ class ProductionConfig(Config):
     BOOTSTRAP_USE_MINIFIED = True
     DEBUG = False
     #  Database Configuration
-    MYSQL_USERNAME = ""
-    MYSQL_PASSWORD = ""
-    MYSQL_HOSTNAME = ""
-    MYSQL_DATABASE = ""
+    MYSQL_USERNAME = get_env_variable("BSFLASK_MYSQL_USERNAME", fallback=None)
+    MYSQL_PASSWORD = get_env_variable("BSFLASK_MYSQL_PASSWORD", fallback=None)
+    MYSQL_HOSTNAME = get_env_variable("BSFLASK_MYSQL_HOSTNAME", fallback=None)
+    MYSQL_DATABASE = get_env_variable("BSFLASK_MYSQL_DATABASE", fallback=None)
     SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://{username}:{password}@{hostname}/{database}'\
         .format(username=MYSQL_USERNAME, password=MYSQL_PASSWORD,
                 hostname=MYSQL_HOSTNAME, database=MYSQL_DATABASE)

src/resources/utilities.py

@@ -17,6 +17,7 @@
 """
 
 from flask_cache import Cache
+import os
 
 cache = Cache()
 
@@ -46,3 +47,31 @@ def to_zero_count(page_no):
     except (TypeError, ValueError):  # page_no is not an int
         page_no = 0
     return page_no
+
+
+def get_env_variable(variable, fallback):
+    """
+    Will try to retrieve the environment variable from the system and if it fails
+    it returns the fallback value.
+    
+    Args:
+        variable: The environment variable that should be retrieved
+        fallback: The default return value in case the environment variable is not retrieved
+    
+    Returns:
+        On success is returns the variable's value from the environment, on failure it returns the
+        value provided by fallback
+    
+    >>> get_env_variable('HOMES', 'fallback')
+    'fallback'
+    
+    >>> import os
+    >>> os.environ['TEST'] = '13'
+    >>> get_env_variable("TEST", "14")
+    '13'
+    
+    """
+    try:
+        return os.environ[variable]
+    except KeyError:
+        return fallback