Move shared code to testlib

Signed-off-by: Andrey Berezin <a.berezin@yadro.com>

src/frostfs_testlib/resources/optionals.py

@@ -0,0 +1,26 @@
+import os
+
+
+def str_to_bool(input: str) -> bool:
+    return input in ["true", "True", "1"]
+
+
+# Override these optional params to not comment/modify code during local development. Use with caution.
+# Node under test. Set this to occupy exact node.
+OPTIONAL_NODE_UNDER_TEST = os.getenv("OPTIONAL_NODE_UNDER_TEST")
+
+# Node under load. Set this to target load on exact node.
+OPTIONAL_NODE_UNDER_LOAD = os.getenv("OPTIONAL_NODE_UNDER_LOAD")
+
+# Set this to True to disable failover commands. I.E. node which supposed to be stopped will not be actually stopped.
+OPTIONAL_FAILOVER_ENABLED = str_to_bool(os.getenv("OPTIONAL_FAILOVER_ENABLED", "true"))
+
+# Set this to True to disable background load. I.E. node which supposed to be stopped will not be actually stopped.
+OPTIONAL_BACKGROUND_LOAD_ENABLED = str_to_bool(
+    os.getenv("OPTIONAL_BACKGROUND_LOAD_ENABLED", "true")
+)
+
+# Set this to False for disable autouse fixture like node healthcheck during developing time.
+OPTIONAL_AUTOUSE_FIXTURES_ENABLED = str_to_bool(
+    os.getenv("OPTIONAL_AUTOUSE_FIXTURES_ENABLED", "true")
+)