[Do Not Merge] add resume and view mode in python experiment (#3490)

nni/experiment/experiment.py

@@ -75,6 +75,7 @@ class Experiment:
         self.id: Optional[str] = None
         self.port: Optional[int] = None
         self._proc: Optional[Popen] = None
+        self.mode = 'new'
 
         args = [config, training_service]  # deal with overloading
         if isinstance(args[0], (str, list)):
@@ -101,7 +102,10 @@ class Experiment:
         """
         atexit.register(self.stop)
 
+        if self.mode == 'new':
             self.id = management.generate_experiment_id()
+        else:
+            self.config = launcher.get_stopped_experiment_config(self.id, self.mode)
 
         if self.config.experiment_working_directory is not None:
             log_dir = Path(self.config.experiment_working_directory, self.id, 'log')
@@ -109,7 +113,7 @@ class Experiment:
             log_dir = Path.home() / f'nni-experiments/{self.id}/log'
         nni.runtime.log.start_experiment_log(self.id, log_dir, debug)
 
-        self._proc = launcher.start_experiment(self.id, self.config, port, debug)
+        self._proc = launcher.start_experiment(self.id, self.config, port, debug, mode=self.mode)
         assert self._proc is not None
 
         self.port = port  # port will be None if start up failed
@@ -189,6 +193,42 @@ class Experiment:
         _logger.info('Connect to port %d success, experiment id is %s, status is %s.', port, experiment.id, status)
         return experiment
 
+    @classmethod
+    def resume(cls, experiment_id: str, port: int, wait_completion: bool = True, debug: bool = False):
+        """
+        Resume a stopped experiment.
+
+        Parameters
+        ----------
+        experiment_id
+            The stopped experiment id.
+        """
+        experiment = Experiment()
+        experiment.mode = 'resume'
+        if wait_completion:
+            experiment.run(port, debug)
+        else:
+            experiment.start(port, debug)
+            return experiment
+
+    @classmethod
+    def view(cls, experiment_id: str, port: int, wait_completion: bool = True, debug: bool = False):
+        """
+        View a stopped experiment.
+
+        Parameters
+        ----------
+        experiment_id
+            The stopped experiment id.
+        """
+        experiment = Experiment()
+        experiment.mode = 'view'
+        if wait_completion:
+            experiment.run(port, debug)
+        else:
+            experiment.start(port, debug)
+            return experiment
+
     def get_status(self) -> str:
         """
         Return experiment status as a str.

nni/experiment/launcher.py

@@ -18,16 +18,19 @@ import nni.runtime.protocol
 from .config import ExperimentConfig
 from .pipe import Pipe
 from . import rest
-from ..tools.nnictl.config_utils import Experiments
+from ..tools.nnictl.config_utils import Experiments, Config
+from ..tools.nnictl.nnictl_utils import update_experiment
 
 _logger = logging.getLogger('nni.experiment')
 
 
-def start_experiment(exp_id: str, config: ExperimentConfig, port: int, debug: bool) -> Popen:
+def start_experiment(exp_id: str, config: ExperimentConfig, port: int, debug: bool, mode: str = 'new') -> Popen:
     proc = None
 
     config.validate(initialized_tuner=False)
     _ensure_port_idle(port)
+
+    if mode != 'view':
         if isinstance(config.training_service, list): # hybrid training service
             _ensure_port_idle(port + 1, 'Hybrid training service requires an additional port')
         elif config.training_service.platform in ['remote', 'openpai', 'kubeflow', 'frameworkcontroller', 'adl']:
@@ -35,12 +38,13 @@ def start_experiment(exp_id: str, config: ExperimentConfig, port: int, debug: bo
 
     try:
         _logger.info('Creating experiment, Experiment ID: %s', colorama.Fore.CYAN + exp_id + colorama.Style.RESET_ALL)
-        start_time, proc = _start_rest_server(config, port, debug, exp_id)
+        start_time, proc = _start_rest_server(config, port, debug, exp_id, mode=mode)
         _logger.info('Statring web server...')
         _check_rest_server(port)
         platform = 'hybrid' if isinstance(config.training_service, list) else config.training_service.platform
         _save_experiment_information(exp_id, port, start_time, platform,
                                      config.experiment_name, proc.pid, config.experiment_working_directory)
+        if mode != 'view':
             _logger.info('Setting up...')
             rest.post(port, '/experiment', config.json())
         return proc
@@ -98,7 +102,8 @@ def _ensure_port_idle(port: int, message: Optional[str] = None) -> None:
         raise RuntimeError(f'Port {port} is not idle {message}')
 
 
-def _start_rest_server(config: ExperimentConfig, port: int, debug: bool, experiment_id: str, pipe_path: str = None) -> Tuple[int, Popen]:
+def _start_rest_server(config: ExperimentConfig, port: int, debug: bool, experiment_id: str, pipe_path: str = None,
+                       mode: str = 'new') -> Tuple[int, Popen]:
     if isinstance(config.training_service, list):
         ts = 'hybrid'
     else:
@@ -110,12 +115,16 @@ def _start_rest_server(config: ExperimentConfig, port: int, debug: bool, experim
         'port': port,
         'mode': ts,
         'experiment_id': experiment_id,
-        'start_mode': 'new',
+        'start_mode': mode,
         'log_level': 'debug' if debug else 'info',
     }
     if pipe_path is not None:
         args['dispatcher_pipe'] = pipe_path
 
+    if mode == 'view':
+        args['start_mode'] = 'resume'
+        args['readonly'] = 'true'
+
     node_dir = Path(nni_node.__path__[0])
     node = str(node_dir / ('node.exe' if sys.platform == 'win32' else 'node'))
     main_js = str(node_dir / 'main.js')
@@ -150,3 +159,19 @@ def _check_rest_server(port: int, retry: int = 3) -> None:
 def _save_experiment_information(experiment_id: str, port: int, start_time: int, platform: str, name: str, pid: int, logDir: str) -> None:
     experiments_config = Experiments()
     experiments_config.add_experiment(experiment_id, port, start_time, platform, name, pid=pid, logDir=logDir)
+
+
+def get_stopped_experiment_config(exp_id: str, mode: str) -> None:
+    update_experiment()
+    experiments_config = Experiments()
+    experiments_dict = experiments_config.get_all_experiments()
+    experiment_metadata = experiments_dict.get(exp_id)
+    if experiment_metadata is None:
+        logging.error('Id %s not exist!', exp_id)
+        return
+    if experiment_metadata['status'] != 'STOPPED':
+        logging.error('Only stopped experiments can be %sed!', mode)
+        return
+    experiment_config = Config(exp_id, experiment_metadata['logDir']).get_config()
+    config = ExperimentConfig(**experiment_config)
+    return config