introduce a WebSocket Controller

[jeremyandrews]

• introduce WebSocket Controller allowing real-time control of load test, optionally disable with --no-websocket, supports the following commands: o exit (and quit) exit the WebSocket Controller o stop stops the running load test (and exits the controller) o hatchrate (and hatch_rate) FLOAT sets per-second rate users hatch o config returns the current load test configuration in json format o metrics (and stats) returns metrics for the current load test in json format
• WebSocket Controller bind host defaults to 0.0.0.0, can be configured with --websocket-host
• WebSocket Controller bind port defaults to 5117, can be configured with --websocket-port
• WebSocket Controller defaults can be changed: o default to not enabling WebSocket Controller: GooseDefault::NoWebSocket (bool) o default host to bind WebSocket Controller to: GooseDefault::WebSocketHost (&str) o default port to bind WebSocket Controller to: GooseDefault::WebSocketPort (usize)
  • renamed run time options --no-controller, --controller-host, --controller-port to --no-telnet, --telnet-host, --telnet-port to differentiate between controllers
  • renamed GooseDefault::NoController,GooseDefault::ConterllerHost, and GooseDefault::ControllerPort to GooseDefault::NoTelnet,GooseDefault::TelnetHost, and GooseDefault::TelnetPort to differentiate between controllers
  • requests to the WebSocket Controller must be in the following format:

    {
    `request`: String,
    }

  • response from the WebSocket Controller are always in the following format:

    {
    response: String,
    success: bool,
    error: Option<String>,
    }

    For example:

% websocat ws://127.0.0.1:5117
{"request": "hatchrate 5"}
{"response":"set hatch_rate","success":true,"error":null}
{"request": "config"}
{"response":"{\"help\":false,\"version\":false,\"list\":false,\"host\":\"http://apache/\",\"users\":1,\"hatch_rate\":\"5\",\"run_time\":\"\",\"log_level\":0,\"log_file\":\"\",\"verbose\":1,\"running_metrics\":null,\"no_reset_metrics\":false,\"no_metrics\":false,\"no_task_metrics\":false,\"no_error_summary\":false,\"report_file\":\"\",\"requests_file\":\"\",\"requests_format\":\"json\",\"debug_file\":\"\",\"debug_format\":\"json\",\"no_debug_body\":false,\"status_codes\":false,\"no_telnet\":false,\"telnet_host\":\"0.0.0.0\",\"telnet_port\":5116,\"no_websocket\":false,\"websocket_host\":\"0.0.0.0\",\"websocket_port\":5117,\"throttle_requests\":0,\"sticky_follow\":false,\"manager\":false,\"expect_workers\":null,\"no_hash_check\":false,\"manager_bind_host\":\"\",\"manager_bind_port\":0,\"worker\":false,\"manager_host\":\"\",\"manager_port\":0}","success":true,"error":null}
{"request": "foobar"}
{"response":"unrecognized command","success":false,"error":"unrecognized command"}
foobar
{"response":"unrecognized json request","success":false,"error":"unrecognized json request"}
{"request": "exit"}