Add an on/off switch for the MAS facility.

MAS-WP-0007 is finished. power.sh scales the MX and statute together
and records the power annotation. apply.sh keeps an off facility off.
The live facility was annotated power=on and was not restarted.

Assistant: grok
Assistant-Session: 01a198fa-fd27-7e41-a0a2-57355c3e4efd

deploy/railiance/facility.py

@@ -0,0 +1,81 @@
+"""Render the MAS facility manifest for a power state.
+
+This file does not talk to the cluster. power.sh and apply.sh do.
+"""
+
+from __future__ import annotations
+
+import sys
+
+SWITCHABLE = ("mas-mx", "mas-statute")
+
+
+def render(manifest: str, image: str, power: str) -> str:
+    """Return the manifest with IMAGE filled in and replicas set from power.
+
+    `on` keeps one replica of each switchable Deployment. `off` sets both
+    to zero. Services, the evidence volume, the Ingress, and the
+    ExternalSecret are copied through unchanged.
+    """
+    if power not in ("on", "off"):
+        raise ValueError(f"power must be on or off, got {power!r}")
+    if not image or any(ch.isspace() for ch in image):
+        raise ValueError("image must be a single token")
+    if "image: IMAGE" not in manifest:
+        raise ValueError("manifest has no image: IMAGE placeholder")
+
+    rendered = manifest.replace("image: IMAGE", f"image: {image}")
+    docs = rendered.split("\n---\n")
+    seen: set[str] = set()
+    out: list[str] = []
+    for doc in docs:
+        name = _deployment_name(doc)
+        if name in SWITCHABLE:
+            seen.add(name)
+            doc = _set_replicas(doc, 0 if power == "off" else 1)
+        out.append(doc)
+    missing = [name for name in SWITCHABLE if name not in seen]
+    if missing:
+        raise ValueError("manifest is missing Deployments: " + ", ".join(missing))
+    return "\n---\n".join(out)
+
+
+def _deployment_name(doc: str) -> str | None:
+    kind = None
+    name = None
+    for line in doc.splitlines():
+        if line.startswith("kind:"):
+            kind = line.split(":", 1)[1].strip()
+        elif line.startswith("  name:") and name is None:
+            name = line.split(":", 1)[1].strip()
+    if kind == "Deployment":
+        return name
+    return None
+
+
+def _set_replicas(doc: str, count: int) -> str:
+    lines = doc.splitlines(keepends=True)
+    found = 0
+    out = []
+    for line in lines:
+        if line.startswith("  replicas:"):
+            found += 1
+            newline = "\n" if line.endswith("\n") else ""
+            out.append(f"  replicas: {count}{newline}")
+        else:
+            out.append(line)
+    if found != 1:
+        raise ValueError(f"expected one replicas field, found {found}")
+    return "".join(out)
+
+
+def main(argv: list[str]) -> int:
+    if len(argv) != 4 or argv[1] != "render":
+        print("usage: facility.py render IMAGE on|off", file=sys.stderr)
+        return 2
+    sys.stdout.write(render(sys.stdin.read(), argv[2], argv[3]))
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))