[WIP] re-implement Gaggle removing compile-time feature

src/gaggle/common.rs

@@ -0,0 +1,33 @@
+pub struct GaggleEcho {
+    _sequence: u32,
+    _acknowledge: Option<u32>,
+}
+
+/// Commands sent to/from Works and Managers to control a Gaggle.
+pub enum GaggleCommand {
+    ManagerShuttingDown,
+    Shutdown,
+    WorkerShuttingDown,
+    /// Notification that a Worker is standing by and ready to start the load test.
+    WorkerIsReady,
+}
+
+pub enum GagglePhase {
+    WaitingForWorkers,
+}
+
+pub enum GaggleCommands {
+    Control(GaggleCommand),
+    Echo(GaggleEcho),
+    // Not Gaggle-specific
+    //Error(GooseErrorMetrics),
+    //Request(GooseRequestMetrics),
+    //Scenario(ScenarioMetrics),
+    //Transaction(TransactionMetrics),
+}
+
+/// Constant defining Goose's default port when running a Gaggle.
+pub(crate) const DEFAULT_GAGGLE_PORT: &str = "5115";
+
+/// Constant defining Goose's default manager_host when running a Gaggle.
+pub(crate) const DEFAULT_GAGGLE_HOST: &str = "127.0.0.1";