From bfef114690b0889f61601c86dad91606247427c8 Mon Sep 17 00:00:00 2001
From: Andrew Baldwin <andrew.baldwin44@gmail.com>
Date: Thu, 18 Jan 2024 15:14:29 -0500
Subject: [PATCH] Add --config-users parser argument

---
 locust/argument_parser.py |  7 +++++++
 locust/main.py            | 28 ++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/locust/argument_parser.py b/locust/argument_parser.py
index 2c8f950f14..024df355f2 100644
--- a/locust/argument_parser.py
+++ b/locust/argument_parser.py
@@ -306,6 +306,13 @@ def setup_parser_arguments(parser):
         dest="list_commands",
         help="Show list of possible User classes and exit",
     )
+    parser.add_argument(
+        "--config-users",
+        type=str,
+        nargs="*",
+        help="User configuration as a JSON string or file. A list of arguments or an Array of JSON configuration may be provided",
+        env_var="LOCUST_CONFIG_USERS",
+    )
 
     web_ui_group = parser.add_argument_group("Web UI options")
     web_ui_group.add_argument(
diff --git a/locust/main.py b/locust/main.py
index 27eb44ccb1..7855cfb706 100644
--- a/locust/main.py
+++ b/locust/main.py
@@ -3,6 +3,7 @@
 import errno
 import logging
 import os
+import json
 import signal
 import sys
 import time
@@ -358,6 +359,33 @@ def kill_workers(children):
         available_user_tasks=available_user_tasks,
     )
 
+    if options.config_users:
+        for json_user_config in options.config_users:
+            try:
+                if json_user_config.endswith(".json"):
+                    with open(json_user_config) as file:
+                        user_config = json.load(file)
+                else:
+                    user_config = json.loads(json_user_config)
+
+                def ensure_user_class_name(config):
+                    if "user_class_name" not in config:
+                        logger.error("The user config must specify a user_class_name")
+                        sys.exit(-1)
+
+                if isinstance(user_config, list):
+                    for config in user_config:
+                        ensure_user_class_name(config)
+
+                        environment.update_user_class(config)
+                else:
+                    ensure_user_class_name(user_config)
+
+                    environment.update_user_class(user_config)
+            except Exception as e:
+                logger.error(f"The --config-users arugment must be in valid JSON string or file: {e}")
+                sys.exit(-1)
+
     if (
         shape_class
         and not shape_class.use_common_options