Change default number of loadgens from crashing to mean all of them.

README.md

@@ -53,7 +53,7 @@ options:
   --loadgen-list LOADGEN_LIST
                         A comma-separated list of ssh servers on which to launch locust workers
   --loadgens LOADGENS, -l LOADGENS
-                        Number of servers to run locust workers on
+                        Number of servers to run locust workers on. Defaults to -1, meaning all of them.
   --processes PROCESSES
                         This is passed on to locust unchanged and determines the number of worker processes per load generator.
   --selenium            Start selenium server on load gens for use with locust-plugins's WebdriverUser

locust_swarm/swarm.py

@@ -69,8 +69,8 @@
     "--loadgens",
     "-l",
     type=int,
-    default=1,
-    help="Number of servers to run locust workers on",
+    default=-1,
+    help="Number of servers to run locust workers on. Defaults to -1, meaning all of them.",
 )
 parser.add_argument(
     "--processes-per-loadgen",
@@ -381,10 +381,10 @@ def main():
         parser.error(
             f"--processes-per-loadgen has been removed in favour of locusts native --processes parameter (you had it set to {args.processes_per_loadgen})"
         )
-    if args.loadgens < 1:
-        parser.error("loadgens parameter must be 1 or higher")
     worker_process_count = args.processes * args.loadgens
     loadgen_list = args.loadgen_list.split(",")
+    if args.loadgens < 0:
+        args.loadgens = len(loadgen_list)
 
     try:
         subprocess.check_output(