Add weighting support.

main.py

@@ -17,22 +17,22 @@ def hello_world():
     return "Target offload dispatcher"
 
 
+prom = get_prom_client()
+
+
 @app.route("/offload_target")
 def offload_target():
     expected_size = int(request.args.get("SIZE_HINT", 20*1024*1024*1024))
-    targets = copy.deepcopy(app.config["TARGETS"])
-    random.shuffle(targets)
-    prom = get_prom_client()
-    for target in targets:
-        app.logger.info(f"Considering target {target['url']}...")
-        result = prom.custom_query(query=target["free_space"]["query"])
-        if len(result) != 1:
-            continue
-        result = result[0]
-        target_free_space = int(result['value'][1])
-        expected_free_space = target_free_space - expected_size
-        app.logger.info(f"Available space: {target_free_space} Expected size: {expected_size}")
-        if expected_free_space < target["free_space"].get("minimum", 1024 * 1024 * 1024 * 500):
-            continue
-        return {"url": target["url"]}
-    return "Unable to allocate target", 500
+    weights = [x.get("weight", 100) for x in app.config["TARGETS"]]
+    target = random.choices(app.config["TARGETS"], weights=weights)[0]
+    app.logger.info(f"Considering target {target['url']}...")
+    result = prom.custom_query(query=target["free_space"]["query"])
+    if len(result) != 1:
+        return "Unable to allocate target. Can't get space info.", 500
+    result = result[0]
+    target_free_space = int(result['value'][1])
+    expected_free_space = target_free_space - expected_size
+    app.logger.info(f"Available space: {target_free_space} Expected size: {expected_size}")
+    if expected_free_space < target["free_space"].get("minimum", 1024 * 1024 * 1024 * 500):
+        return "Unable to allocate target. Not enough space on selected machine.", 507
+    return {"url": target["url"]}