feat: support smolmachines bottle commit

bot_bottle/cli/commit.py

@@ -1,20 +1,21 @@
-"""commit: freeze a running Docker bottle's container state to a local image.
+"""commit: freeze a running bottle's state to a resumable artifact.
 
-Runs `docker commit <container> <image-tag>` on the active agent
-container and stores the image tag in per-bottle state so the next
-`./cli.py resume <slug>` boots from that snapshot instead of
-rebuilding from the Dockerfile.
-
-Only the Docker backend is supported. Smolmachines VMs have no
-container-level commit API in the current smolvm CLI surface.
+Docker bottles are committed to a local Docker image. Smolmachines
+bottles are packed from the running VM into a `.smolmachine` artifact.
+The resulting reference is stored in per-bottle state so the next
+`./cli.py resume <slug>` boots from the snapshot instead of rebuilding
+from the Dockerfile.
 """
 
 from __future__ import annotations
 
 import argparse
+from pathlib import Path
 
 from ..backend import enumerate_active_agents
 from ..backend.docker.util import commit_container
+from ..backend.smolmachines.smolvm import pack_create_from_vm
+from ..bottle_state import bottle_state_dir
 from ..bottle_state import mark_preserved, read_metadata, write_committed_image
 from ..log import die, info
 from ._common import PROG
@@ -23,6 +24,7 @@ from . import tui
 
 _COMMITTED_IMAGE_PREFIX = "bot-bottle-committed-"
 _DOCKER_BACKENDS = {"docker", ""}
+_SMOLMACHINES_BACKEND = "smolmachines"
 
 
 def _committed_image_tag(slug: str) -> str:
@@ -33,6 +35,19 @@ def _agent_container_name(slug: str) -> str:
     return f"bot-bottle-{slug}"
 
 
+def _agent_machine_name(slug: str) -> str:
+    return f"bot-bottle-{slug}"
+
+
+def _committed_smolmachine_output(slug: str) -> Path:
+    return bottle_state_dir(slug) / "committed-smolmachine"
+
+
+def _committed_smolmachine_artifact(slug: str) -> Path:
+    output = _committed_smolmachine_output(slug)
+    return output.with_name(f"{output.name}.smolmachine")
+
+
 def cmd_commit(argv: list[str]) -> int:
     parser = argparse.ArgumentParser(prog=f"{PROG} commit", add_help=True)
     parser.add_argument(
@@ -58,18 +73,33 @@ def cmd_commit(argv: list[str]) -> int:
 
     metadata = read_metadata(slug)
     backend = metadata.backend if metadata else ""
-    if backend not in _DOCKER_BACKENDS:
+    if backend in _DOCKER_BACKENDS:
+        container = _agent_container_name(slug)
+        image_tag = _committed_image_tag(slug)
+
+        commit_container(container, image_tag)
+        write_committed_image(slug, image_tag)
+        mark_preserved(slug)
+        info(f"to resume from this snapshot: ./cli.py resume {slug}")
+        info(f"to export for migration:      docker save {image_tag} -o {slug}.tar")
+        return 0
+
+    if backend == _SMOLMACHINES_BACKEND:
+        machine = _agent_machine_name(slug)
+        output = _committed_smolmachine_output(slug)
+        output.parent.mkdir(parents=True, exist_ok=True)
+        pack_create_from_vm(machine, output)
+        artifact = _committed_smolmachine_artifact(slug)
+        write_committed_image(slug, str(artifact))
+        mark_preserved(slug)
+        info(f"to resume from this snapshot: ./cli.py resume {slug}")
+        info(f"to export for migration:      cp {artifact} {slug}.smolmachine")
+        return 0
+
+    if backend:
         die(
-            f"commit is only supported for the docker backend; "
+            f"commit is only supported for the docker and smolmachines backends; "
             f"bottle {slug!r} uses {backend!r}"
         )
-
-    container = _agent_container_name(slug)
-    image_tag = _committed_image_tag(slug)
-
-    commit_container(container, image_tag)
-    write_committed_image(slug, image_tag)
-    mark_preserved(slug)
-    info(f"to resume from this snapshot: ./cli.py resume {slug}")
-    info(f"to export for migration:      docker save {image_tag} -o {slug}.tar")
-    return 0
+    die(f"commit cannot determine the backend for bottle {slug!r}")
+    return 1