Add cached image quickstart

bot_bottle/backend/__init__.py

@@ -78,6 +78,9 @@ class BottleSpec:
     # True when launched via --headless (no TTY, no interactive prompts).
     # The git-gate host-key preflight uses this to error rather than prompt.
     headless: bool = False
+    # Image startup policy. "fresh" preserves the normal build path;
+    # "cached" reuses the current local image/artifact without rebuilding.
+    image_policy: str = "fresh"
 
 
 @dataclass(frozen=True)

bot_bottle/backend/docker/compose.py

@@ -180,10 +180,6 @@ def _sidecar_bundle_service(plan: DockerBottlePlan) -> dict[str, Any]:
 
     service: dict[str, Any] = {
         "image": SIDECAR_BUNDLE_IMAGE,
-        "build": {
-            "context": _REPO_DIR,
-            "dockerfile": SIDECAR_BUNDLE_DOCKERFILE,
-        },
         "container_name": sidecar_bundle_container_name(plan.slug),
         "networks": {
             "internal": {"aliases": internal_aliases},
@@ -192,6 +188,11 @@ def _sidecar_bundle_service(plan: DockerBottlePlan) -> dict[str, Any]:
         "environment": env,
         "volumes": volumes,
     }
+    if plan.spec.image_policy != "cached":
+        service["build"] = {
+            "context": _REPO_DIR,
+            "dockerfile": SIDECAR_BUNDLE_DOCKERFILE,
+        }
     return service
 
 

bot_bottle/backend/docker/launch.py

@@ -41,7 +41,8 @@ from ...git_gate import (
     provision_git_gate_dynamic_keys,
     revoke_git_gate_provisioned_keys,
 )
-from ...log import info, warn
+from ...image_cache import warn_if_stale
+from ...log import die, info, warn
 from . import network as network_mod
 from . import util as docker_mod
 from .bottle import DockerBottle
@@ -63,6 +64,7 @@ from .compose import (
     write_compose_file,
 )
 from .egress import egress_tls_init
+from .sidecar_bundle import SIDECAR_BUNDLE_IMAGE
 
 
 # Where the repo root lives, for `docker build` context. Computed once.
@@ -100,12 +102,39 @@ def launch(
         # Dockerfile. Sidecar images get built lazily by `docker compose
         # up` via the renderer's `build:` directives.
         committed = read_committed_image(plan.slug)
+        cached_policy = plan.spec.image_policy == "cached"
         if committed and docker_mod.image_exists(committed):
             info(f"using committed image {committed!r}")
+            if cached_policy:
+                warn_if_stale(
+                    f"agent image {committed!r}",
+                    docker_mod.image_created_at(committed),
+                )
             plan = dataclasses.replace(
                 plan,
                 agent_provision=dataclasses.replace(plan.agent_provision, image=committed),
             )
+        elif cached_policy:
+            if not docker_mod.image_exists(plan.image):
+                die(
+                    f"cached agent image {plan.image!r} not found; "
+                    "run without --cached-images to build it"
+                )
+            if not docker_mod.image_exists(SIDECAR_BUNDLE_IMAGE):
+                die(
+                    f"cached sidecar image {SIDECAR_BUNDLE_IMAGE!r} not found; "
+                    "run without --cached-images to build it"
+                )
+            info(f"using cached agent image {plan.image!r}")
+            info(f"using cached sidecar image {SIDECAR_BUNDLE_IMAGE!r}")
+            warn_if_stale(
+                f"agent image {plan.image!r}",
+                docker_mod.image_created_at(plan.image),
+            )
+            warn_if_stale(
+                f"sidecar image {SIDECAR_BUNDLE_IMAGE!r}",
+                docker_mod.image_created_at(SIDECAR_BUNDLE_IMAGE),
+            )
         else:
             docker_mod.build_image(
                 plan.image, _REPO_DIR,

bot_bottle/backend/docker/util.py

@@ -4,6 +4,7 @@ existence, and building images."""
 
 from __future__ import annotations
 
+from datetime import datetime, timezone
 import re
 import shutil
 import subprocess
@@ -186,6 +187,45 @@ def image_id(ref: str) -> str:
     return r.stdout.strip()
 
 
+def image_created_at(ref: str) -> datetime:
+    """Return Docker's image Created timestamp as an aware UTC datetime."""
+    r = subprocess.run(
+        ["docker", "image", "inspect", "--format", "{{.Created}}", ref],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+    if r.returncode != 0:
+        die(
+            f"docker image inspect for {ref!r} failed: "
+            f"{(r.stderr or '').strip() or '<no stderr>'}"
+        )
+    raw = r.stdout.strip()
+    try:
+        return _parse_docker_timestamp(raw)
+    except ValueError:
+        die(f"docker image inspect for {ref!r} returned invalid Created timestamp: {raw!r}")
+
+
+def _parse_docker_timestamp(raw: str) -> datetime:
+    text = raw.strip()
+    if text.endswith("Z"):
+        text = text[:-1] + "+00:00"
+    dot = text.find(".")
+    if dot != -1:
+        tz_plus = text.find("+", dot)
+        tz_minus = text.find("-", dot)
+        tz_candidates = [pos for pos in (tz_plus, tz_minus) if pos != -1]
+        if tz_candidates:
+            tz_pos = min(tz_candidates)
+            frac = text[dot + 1:tz_pos]
+            text = text[:dot + 1] + frac[:6].ljust(6, "0") + text[tz_pos:]
+    dt = datetime.fromisoformat(text)
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=timezone.utc)
+    return dt.astimezone(timezone.utc)
+
+
 def save(ref: str, output: str) -> None:
     """`docker save REF -o OUTPUT`. Writes a tarball of the image
     layers + manifest to the host path. Used by smolmachines

bot_bottle/backend/smolmachines/launch.py

@@ -45,7 +45,8 @@ from ...git_gate import (
     provision_git_gate_dynamic_keys,
     revoke_git_gate_provisioned_keys,
 )
-from ...log import info, warn
+from ...image_cache import warn_if_stale_path
+from ...log import die, info, warn
 from ...bottle_state import (
     egress_state_dir,
     git_gate_state_dir,
@@ -182,10 +183,13 @@ def _start_bundle(
     plan = _provision_git_gate_keys(plan)
     bundle_spec = _bundle_launch_spec(plan, network, proxy_host)
     token_env = _resolve_token_env(plan, dict(os.environ))
-    artifact = _ensure_smolmachine(
-        bundle_spec.image,
-        dockerfile=_bundle.SIDECAR_BUNDLE_DOCKERFILE,
-    )
+    if _image_policy(plan) == "cached":
+        artifact = _cached_smolmachine(bundle_spec.image, label="sidecar")
+    else:
+        artifact = _ensure_smolmachine(
+            bundle_spec.image,
+            dockerfile=_bundle.SIDECAR_BUNDLE_DOCKERFILE,
+        )
     launch = _bundle.start_bundle_vm(
         bundle_spec,
         from_path=artifact,
@@ -467,8 +471,13 @@ def _agent_from_path(plan: SmolmachinesBottlePlan) -> Path:
         committed_path = Path(committed)
         if committed_path.is_file():
             info(f"using committed smolmachine {str(committed_path)!r}")
+            if _image_policy(plan) == "cached":
+                warn_if_stale_path("agent smolmachine artifact", committed_path)
             return committed_path
 
+    if _image_policy(plan) == "cached":
+        return _cached_smolmachine(plan.agent_image, label="agent")
+
     # Build the agent image and pack it into a `.smolmachine`
     # artifact (or hit the per-Dockerfile-digest cache). Runs here,
     # not in prepare, so the docker-build output doesn't garble the
@@ -479,6 +488,35 @@ def _agent_from_path(plan: SmolmachinesBottlePlan) -> Path:
     )
 
 
+def _image_policy(plan: object) -> str:
+    spec = getattr(plan, "spec", None)
+    return str(getattr(spec, "image_policy", "fresh"))
+
+
+def _cached_smolmachine(image_ref: str, *, label: str) -> Path:
+    """Return the cached smolmachine artifact for the current local image.
+
+    This is intentionally buildless: it inspects the existing local Docker
+    image ID and looks for the artifact keyed by that ID. If either side is
+    missing, the caller must use the fresh path to build/pack it.
+    """
+    if not docker_mod.image_exists(image_ref):
+        die(
+            f"cached {label} image {image_ref!r} not found; "
+            "run without --cached-images to build it"
+        )
+    digest = docker_mod.image_id(image_ref).split(":", 1)[-1][:16]
+    sidecar = _SMOLMACHINE_CACHE_DIR / f"{digest}.smolmachine.smolmachine"
+    if not sidecar.is_file():
+        die(
+            f"cached {label} smolmachine artifact for {image_ref!r} not found; "
+            "run without --cached-images to build it"
+        )
+    info(f"using cached {label} smolmachine {str(sidecar)!r}")
+    warn_if_stale_path(f"{label} smolmachine artifact", sidecar)
+    return sidecar
+
+
 def _ensure_smolmachine(image_ref: str, *, dockerfile: str = "") -> Path:
     """Build the agent docker image and convert it into a
     `.smolmachine` artifact, caching the result under