fix: start DocsGPT again when a restore fails after the stack is down

Validating the archive catches a damaged one while DocsGPT is still up, but a
well-formed archive can still hold a corrupt volume tar or a dump statement
psql refuses, and those only surface once the stack is down. The work after
the shutdown now runs inside an error boundary that starts the stack again
before the failure is reported, so a failed restore never leaves the install
stopped.

docsgpt/deploy/commands.py

@@ -419,6 +419,32 @@ def _write_backup(args, context: Context, directory: Path, env, target: Path, im
         backup_format.write_archive(target, dump=dump, volume_tars=volume_tars, manifest=manifest, settings=settings)
 
 
+def _restore_data(context: Context, directory: Path, archive: Path, volumes: list, image: str) -> None:
+    """Put the archive's volumes and database back, with the stack stopped."""
+    with tempfile.TemporaryDirectory() as workspace:
+        work = Path(workspace)
+        backup_format.extract(archive, work)
+        for name in volumes:
+            tar_path = work / backup_format.volume_member(name)
+            if not tar_path.is_file():
+                raise DeployError(f"{archive} is missing the {name} volume it says it contains")
+            print(f"Restoring the {name} volume ...")
+            context.docker.import_volume(f"{PROJECT}_{name}", tar_path, image)
+
+        dump = work / backup_format.DUMP
+        if not dump.is_file():
+            raise DeployError(f"{archive} is missing its database dump")
+        print("Starting the database ...")
+        context.docker.compose(directory, "up", "-d", "--wait", "postgres")
+        print("Restoring the database ...")
+        with dump.open("r", encoding="utf-8") as handle:
+            context.docker.compose(
+                directory, "exec", "-T", "postgres",
+                "psql", "--quiet", "--set", "ON_ERROR_STOP=on", "-U", "docsgpt", "-d", "docsgpt",
+                stdin=handle,
+            )
+
+
 def restore(args, context: Optional[Context] = None) -> int:
     """Put a backup's database and data volumes back over this install."""
     context = context or Context.default(args)
@@ -446,28 +472,14 @@ def restore(args, context: Optional[Context] = None) -> int:
     print("Stopping the stack ...")
     context.docker.compose(directory, *_EVERY_PROFILE, "down")
 
-    with tempfile.TemporaryDirectory() as workspace:
-        work = Path(workspace)
-        backup_format.extract(archive, work)
-        for name in volumes:
-            tar_path = work / backup_format.volume_member(name)
-            if not tar_path.is_file():
-                raise DeployError(f"{archive} is missing the {name} volume it says it contains")
-            print(f"Restoring the {name} volume ...")
-            context.docker.import_volume(f"{PROJECT}_{name}", tar_path, image)
-
-        dump = work / backup_format.DUMP
-        if not dump.is_file():
-            raise DeployError(f"{archive} is missing its database dump")
-        print("Starting the database ...")
-        context.docker.compose(directory, "up", "-d", "--wait", "postgres")
-        print("Restoring the database ...")
-        with dump.open("r", encoding="utf-8") as handle:
-            context.docker.compose(
-                directory, "exec", "-T", "postgres",
-                "psql", "--quiet", "--set", "ON_ERROR_STOP=on", "-U", "docsgpt", "-d", "docsgpt",
-                stdin=handle,
-            )
+    try:
+        _restore_data(context, directory, archive, volumes, image)
+    except BaseException:
+        # The stack is down by now. A corrupt payload inside an otherwise well-formed archive, or a
+        # statement psql refuses, must not leave DocsGPT stopped: start it again, then report.
+        print("The restore failed. Starting DocsGPT again ...", file=sys.stderr)
+        context.docker.compose(directory, "up", "-d", "--remove-orphans", check=False)
+        raise
 
     print("Starting DocsGPT ...")
     context.docker.compose(directory, "up", "-d", "--remove-orphans")