[UX] Support dstack ps -n NUM

Author: peterschmidt85

src/dstack/_internal/cli/commands/ps.py

@@ -36,10 +36,17 @@ def _register(self):
             help="Watch statuses of runs in realtime",
             action="store_true",
         )
+        self._parser.add_argument(
+            "-n",
+            "--last",
+            help="Show only the last N runs. Implies --all",
+            type=int,
+            default=None,
+        )
 
     def _command(self, args: argparse.Namespace):
         super()._command(args)
-        runs = self.api.runs.list(all=args.all)
+        runs = self.api.runs.list(all=args.all, limit=args.last)
         if not args.watch:
             console.print(run_utils.get_runs_table(runs, verbose=args.verbose))
             return
@@ -49,6 +56,6 @@ def _command(self, args: argparse.Namespace):
                 while True:
                     live.update(run_utils.get_runs_table(runs, verbose=args.verbose))
                     time.sleep(LIVE_TABLE_PROVISION_INTERVAL_SECS)
-                    runs = self.api.runs.list(all=args.all)
+                    runs = self.api.runs.list(all=args.all, limit=args.last)
         except KeyboardInterrupt:
             pass

src/dstack/api/_public/runs.py

@@ -691,29 +691,32 @@ def exec_plan(
         logger.warning("The exec_plan() method is deprecated in favor of apply_plan().")
         return self.apply_plan(run_plan=run_plan, repo=repo, reserve_ports=reserve_ports)
 
-    def list(self, all: bool = False) -> List[Run]:
+    def list(self, all: bool = False, limit: Optional[int] = None) -> List[Run]:
         """
         List runs.
 
         Args:
             all: Show all runs (active and finished) if `True`.
+            limit: Limit the number of runs to return. Must be less than 100.
 
         Returns:
             List of runs.
         """
         # Return only one page of latest runs (<=100). Returning all the pages may be costly.
         # TODO: Consider introducing `since` filter with a reasonable default.
-        only_active = not all
+        only_active = not all and limit is None
         runs = self._api_client.runs.list(
             project_name=self._project,
             repo_id=None,
             only_active=only_active,
+            limit=limit or 100,
         )
         if only_active and len(runs) == 0:
             runs = self._api_client.runs.list(
                 project_name=self._project,
                 repo_id=None,
-            )[:1]
+                limit=1,
+            )
         return [self._model_to_run(run) for run in runs]
 
     def get(self, run_name: str) -> Optional[Run]: