Allow to force deploy if deploy parameters change (#644)

Adds `--force` flag to deploy cli command. If deployment parameters
changed and this flag set, mlem will remove old deployment and create
new one.
Also, now there will be no error if parameters changed, but old app does
not have state

Limitations:
* for now only available from cli since adding this to API required a
bit of refactoring
* deployment will always be re-created even if platform allows to just
update old deployment

related #463
closes #549

mlem/cli/deployment.py

@@ -44,7 +44,7 @@
     MlemModel,
 )
 from mlem.telemetry import pass_telemetry_params
-from mlem.ui import echo, no_echo, set_echo
+from mlem.ui import EMOJI_STOP, echo, no_echo, set_echo
 
 logger = logging.getLogger(__name__)
 
@@ -116,6 +116,9 @@ def deploy_run_command(
         model_rev: Optional[str] = option_model_rev,
         project: Optional[str] = option_project,
         file_conf: List[str] = option_file_conf("deployment"),
+        force: bool = Option(
+            False, is_flag=True, help="Force re-create if parameters changed"
+        ),
         **__kwargs__,
     ):
         from mlem.api.commands import deploy
@@ -139,9 +142,18 @@ def deploy_run_command(
         try:
             meta = load_meta(path, project=project, force_type=MlemDeployment)
             if meta != _meta:
-                raise DeploymentError(
-                    f"Different deployment meta already exists at {meta.loc}. Please use `mlem deployment run --load <path> ...`"
-                )
+                if not meta.is_state_empty:
+                    if not force:
+                        raise DeploymentError(
+                            f"Different deployment meta already exists at {meta.loc}. Please use `mlem deployment run --load <path> ...`"
+                        )
+                    echo(
+                        EMOJI_STOP
+                        + "Removing old deployment since parameters changed"
+                    )
+                    meta.remove()
+                with wrap_build_error(type_name, MlemDeployment):
+                    meta = _meta.dump(path, project=project)
         except MlemObjectNotFound:
             with wrap_build_error(type_name, MlemDeployment):
                 meta = _meta.dump(path, project=project)

mlem/core/objects.py

@@ -1277,6 +1277,10 @@ def get_state(self) -> ST:
             self, self.state_type
         ) or self.state_type(declaration=self)
 
+    @property
+    def is_state_empty(self):
+        return self._state_manager.get_state(self, self.state_type) is None
+
     def lock_state(self):
         return self._state_manager.lock_state(self)