chore: Recognize exit status in regression tests (#2571)

Signed-off-by: Roman Gershman <roman@dragonflydb.io>

tests/dragonfly/instance.py

@@ -5,6 +5,7 @@ import aiohttp
 import logging
 from dataclasses import dataclass
 from typing import Dict, Optional, List, Union
+import os
 import re
 import psutil
 import itertools
@@ -162,6 +163,15 @@ class DflyInstance:
         if proc is None:
             return
 
+        # if we have log files, it means that we started a process.
+        # if it died before we could stop it, we should raise an exception
+        if self.log_files:
+            exitcode = proc.poll()
+            if exitcode is not None:
+                if exitcode != 0:
+                    raise Exception(f"Process exited with code {exitcode}")
+                return
+
         logging.debug(f"Stopping instance on {self._port}")
         try:
             if kill:
@@ -193,9 +203,11 @@ class DflyInstance:
             self._port = None
 
         all_args = self.format_args(self.args)
-        logging.debug(f"Starting instance with arguments {all_args} from {self.params.path}")
+        arg_str = " ".join(all_args)
+        bin_path = os.path.realpath(self.params.path)
+        logging.debug(f"Starting {bin_path} with arguments: {arg_str}")
 
-        run_cmd = [self.params.path, *all_args]
+        run_cmd = [bin_path, *all_args]
         if self.params.gdb:
             run_cmd = ["gdb", "--ex", "r", "--args"] + run_cmd
 
@@ -319,7 +331,7 @@ class DflyInstanceFactory:
         args = {**self.args, **kwargs}
         args.setdefault("dbfilename", "")
         vmod = "dragonfly_connection=1,accept_server=1,listener_interface=1,main_service=1,rdb_save=1,replica=1"
-        # args.setdefault("vmodule", vmod)
+        args.setdefault("vmodule", vmod)
 
         for k, v in args.items():
             args[k] = v.format(**self.params.env) if isinstance(v, str) else v