Extra config ini fields (CTFd#1566)

* Move server setting documentation from `config.py` to `config.ini`
* Add support for adding additional config values to `config.ini`
* Rename `CTFd.config.ServerConfig` to `CTFd.config.Config` so that we can instantiate an actual `Config` class and add attributes to it. 
* Closes CTFd#565

CTFd/config.ini

@@ -1,49 +1,181 @@
 [server]
+# SECRET_KEY:
+# The secret value used to creation sessions and sign strings. This should be set to a random string. In the
+# interest of ease, CTFd will automatically create a secret key file for you. If you wish to add this secret key
+# to your instance you should hard code this value to a random static value.
+#
+# You can also remove .ctfd_secret_key from the .gitignore file and commit this file into whatever repository
+# you are using.
+#
+# http://flask.pocoo.org/docs/latest/quickstart/#sessions
 SECRET_KEY =
+
+# DATABASE_URL
+# The URI that specifies the username, password, hostname, port, and database of the server
+# used to hold the CTFd database.
+#
+# If a database URL is not specified, CTFd will automatically create a SQLite database for you to use
+# e.g. mysql+pymysql://root:<YOUR_PASSWORD_HERE>@localhost/ctfd
 DATABASE_URL =
+
+# REDIS_URL
+# The URL to connect to a Redis server. If not specified, CTFd will use the .data folder as a filesystem cache
+#
+# e.g. redis://user:password@localhost:6379
+# http://pythonhosted.org/Flask-Caching/#configuring-flask-caching
 REDIS_URL =
 
 [security]
+# SESSION_COOKIE_HTTPONLY
+# Controls if cookies should be set with the HttpOnly flag. Defaults to True.
 SESSION_COOKIE_HTTPONLY = true
+
+# SESSION_COOKIE_SAMESITE
+# Controls the SameSite attribute on session cookies. Can be Lax or Strict.
+# Should be left as Lax unless the implications are well understood
 SESSION_COOKIE_SAMESITE = Lax
+
+# PERMANENT_SESSION_LIFETIME
+# The lifetime of a session. The default is 604800 seconds (7 days).
 PERMANENT_SESSION_LIFETIME = 604800
-TRUSTED_PROXIES =
 
 [email]
+# MAILFROM_ADDR
+# The email address that emails are sent from if not overridden in the configuration panel.
 MAILFROM_ADDR =
+
+# MAIL_SERVER
+# The mail server that emails are sent from if not overriden in the configuration panel.
 MAIL_SERVER =
+
+# MAIL_PORT
+# The mail port that emails are sent from if not overriden in the configuration panel.
 MAIL_PORT =
+
+# MAIL_USEAUTH
+# Whether or not to use username and password to authenticate to the SMTP server
 MAIL_USEAUTH =
+
+# MAIL_USERNAME
+# The username used to authenticate to the SMTP server if MAIL_USEAUTH is defined
 MAIL_USERNAME =
+
+# MAIL_PASSWORD
+# The password used to authenticate to the SMTP server if MAIL_USEAUTH is defined
 MAIL_PASSWORD =
+
+# MAIL_TLS
+# Whether to connect to the SMTP server over TLS
 MAIL_TLS =
+
+# MAIL_SSL
+# Whether to connect to the SMTP server over SSL
 MAIL_SSL =
+
+# MAILGUN_API_KEY
+# Mailgun API key to send email over Mailgun. As of CTFd v3, Mailgun integration is deprecated.
+# Installations using the Mailgun API should migrate over to SMTP settings.
 MAILGUN_API_KEY =
+
+# MAILGUN_BASE_URL
+# Mailgun base url to send email over Mailgun. As of CTFd v3, Mailgun integration is deprecated.
+# Installations using the Mailgun API should migrate over to SMTP settings.
 MAILGUN_BASE_URL =
 
 [uploads]
+# UPLOAD_PROVIDER
+# Specifies the service that CTFd should use to store files.
+# Can be set to filesystem or s3
 UPLOAD_PROVIDER = filesystem
+
+# UPLOAD_FOLDER
+# The location where files are uploaded under the filesystem uploader.
+# The default destination is the CTFd/uploads folder.
 UPLOAD_FOLDER =
+
+# AWS_ACCESS_KEY_ID
+# AWS access token used to authenticate to the S3 bucket. Only used under the s3 uploader.
 AWS_ACCESS_KEY_ID =
+
+# AWS_SECRET_ACCESS_KEY
+# AWS secret token used to authenticate to the S3 bucket. Only used under the s3 uploader.
 AWS_SECRET_ACCESS_KEY =
+
+# AWS_S3_BUCKET
+# The unique identifier for your S3 bucket. Only used under the s3 uploader.
 AWS_S3_BUCKET =
+
+# AWS_S3_ENDPOINT_URL
+# A URL pointing to a custom S3 implementation. Only used under the s3 uploader.
 AWS_S3_ENDPOINT_URL =
 
 [logs]
+# LOG_FOLDER
+# The location where logs are written. These are the logs for CTFd key submissions, registrations, and logins. The default location is the CTFd/logs folder.
 LOG_FOLDER =
 
 [optional]
+# REVERSE_PROXY
+# Specifies whether CTFd is behind a reverse proxy or not. Set to true if using a reverse proxy like nginx.
+# You can also specify a comma seperated set of numbers specifying the reverse proxy configuration settings.
+# See https://werkzeug.palletsprojects.com/en/0.15.x/middleware/proxy_fix/#werkzeug.middleware.proxy_fix.ProxyFix.
+# For example to configure `x_for=1, x_proto=1, x_host=1, x_port=1, x_prefix=1` specify `1,1,1,1,1`.
+# If you specify `true` CTFd will default to the above behavior with all proxy settings set to 1.
 REVERSE_PROXY =
+
+# TEMPLATES_AUTO_RELOAD
+# Specifies whether Flask should check for modifications to templates and reload them automatically. Defaults to true.
 TEMPLATES_AUTO_RELOAD =
+
+# SQLALCHEMY_TRACK_MODIFICATIONS
+# Automatically disabled to suppress warnings and save memory.
+# You should only enable this if you need it.
+# Defaults to false.
 SQLALCHEMY_TRACK_MODIFICATIONS =
+
+# SWAGGER_UI
+# Enable the Swagger UI endpoint at /api/v1/
 SWAGGER_UI =
+
+# UPDATE_CHECK
+# Specifies whether or not CTFd will check whether or not there is a new version of CTFd. Defaults True.
 UPDATE_CHECK =
+
+# APPLICATION_ROOT
+# Specifies what path CTFd is mounted under. It can be used to run CTFd in a subdirectory.
+# Example: /ctfd
 APPLICATION_ROOT =
+
+# SERVER_SENT_EVENTS
+# Specifies whether or not to enable the Server-Sent Events based Notifications system.
+# Defaults to true
 SERVER_SENT_EVENTS =
+
+# HTML_SANITIZATION
+# Specifies whether CTFd should sanitize HTML content
+# Defaults to false
 HTML_SANITIZATION =
+
+# SQLALCHEMY_MAX_OVERFLOW
+# Specifies the max_overflow setting for SQLAlchemy's Engine
+# https://docs.sqlalchemy.org/en/13/core/engines.html#sqlalchemy.create_engine
+# https://flask-sqlalchemy.palletsprojects.com/en/2.x/config/#configuration-keys
 SQLALCHEMY_MAX_OVERFLOW =
+
+# SQLALCHEMY_POOL_PRE_PING
+# Specifies the pool_pre_ping setting for SQLAlchemy's Engine
+# https://docs.sqlalchemy.org/en/13/core/engines.html#sqlalchemy.create_engine
+# https://flask-sqlalchemy.palletsprojects.com/en/2.x/config/#configuration-keys
 SQLALCHEMY_POOL_PRE_PING =
 
 [oauth]
+# OAUTH_CLIENT_ID
+# Register an event at https://majorleaguecyber.org/ and use the Client ID here
 OAUTH_CLIENT_ID =
+
+# OAUTH_CLIENT_ID
+# Register an event at https://majorleaguecyber.org/ and use the Client Secret here
 OAUTH_CLIENT_SECRET =
+
+[extra]
+# The extra section can be used to specify additional values to be loaded into CTFd's configuration