ChangeLogLevel changes proxy log level to correspond to the logrus log level 'level'.

GetMagicMark returns the magic marker with which each packet must be marked.

NewProxy creates a Proxy to keep track of redirects.

HTTPLogRecord wraps an accesslog.LogRecord so that we can define methods with a receiver.

Proxy maintains state about redirects.

ProxySource returns information about the endpoint being proxied.

RedirectImplementation is the generic proxy redirect interface that each proxy redirect type must implement.