Added new Host bridge service for use with Admin UI

Author: rgaudin

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Added new Host bridge service for use with Admin UI
+
 ### Changed
 
 - Based on pi-gen `2025-10-01-raspios-trixie`

tree/stage2/07-sys-configurator/01-run.sh

@@ -12,3 +12,16 @@ on_chroot << EOF
 systemctl daemon-reload
 systemctl enable offspot-runtime.service
 EOF
+
+on_chroot << EOF
+python3 -m venv /usr/local/mekhenet-python
+/usr/local/mekhenet-python/bin/pip install fastapi==0.121.0 uvicorn==0.38.0
+EOF
+
+install -m 755 files/mekhenet.py       "${ROOTFS_DIR}/usr/local/mekhenet-python/lib/python3.13/site-packages/"
+install -m 755 files/mekhenet.service       "${ROOTFS_DIR}/etc/systemd/system/"
+
+on_chroot << EOF
+systemctl daemon-reload
+systemctl enable mekhenet.service
+EOF

tree/stage2/07-sys-configurator/files/mekhenet.py

@@ -0,0 +1,78 @@
+"""mekhenet - simple HTTP API to pass command from services to host via socket
+
+curl --unix-socket /run/offspot/mekhenet.sock http://host/service-is-enabled/ssh
+"""
+
+import subprocess
+from pathlib import Path
+from typing import Annotated
+
+from fastapi import FastAPI
+from fastapi import Path as FastAPIPath
+
+allowed_toggle_actions = ("enable", "disable")
+allowed_services = ("ssh",)
+systemctl_path = Path("/usr/bin/systemctl")
+
+app = FastAPI()
+
+
+@app.get("/reboot/{after_seconds}")
+async def request_host_reboot(
+    after_seconds: Annotated[
+        int, FastAPIPath(title="Nb. of seconds after which to reboot")
+    ],
+):
+    reboot = subprocess.run(
+        [
+            str(systemctl_path),
+            "reboot",
+            "--when",
+            f"+{after_seconds!s}s",
+        ],
+        check=False,
+    )
+    return {"success": reboot.returncode == 0}
+
+
+@app.get("/toggle-service/{action}/{name}")
+async def request_service_toggle(
+    action: Annotated[str, FastAPIPath(title="Action to use (enable/disable)")],
+    name: Annotated[str, FastAPIPath(title="Name of service to toggle")],
+):
+    if action not in allowed_toggle_actions:
+        return {
+            "success": False,
+            "details": f"Forbidden action. Only {', '.join(allowed_toggle_actions)}",
+        }
+    if name not in allowed_services:
+        return {
+            "success": False,
+            "details": "Forbidden service.",
+        }
+    toggle = subprocess.run(
+        [str(systemctl_path), action, name],
+        check=False,
+    )
+    return {"success": toggle.returncode == 0}
+
+
+@app.get("/service-is-enabled/{name}")
+async def request_service_enabled(
+    name: Annotated[str, FastAPIPath(title="Name of service to query")],
+):
+    if name not in allowed_services:
+        return {
+            "success": False,
+            "details": "Forbidden service.",
+        }
+    toggle = subprocess.run(
+        [str(systemctl_path), "is-enabled", name],
+        text=True,
+        capture_output=True,
+        check=False,
+    )
+    if toggle.stdout.strip() in ("enabled", "disabled"):
+        return {"success": True, "enabled": toggle.stdout.strip() == "enabled"}
+
+    return {"success": False, "details": toggle.stdout.splitlines()[0].strip()}

tree/stage2/07-sys-configurator/files/mekhenet.service

@@ -0,0 +1,19 @@
+[Unit]
+Description=Mekhenet Host/Admin bridge
+Requires=network.target internet-check.service
+After=network.target internet-check.service
+
+[Service]
+ExecStart=/usr/local/mekhenet-python/bin/uvicorn --uds /run/offspot/mekhenet.sock --app-dir /usr/local/mekhenet-python/lib/python3.13/site-packages/ "mekhenet:app"
+
+RuntimeDirectory=offspot
+Type=idle
+Restart=always
+TimeoutStartSec=10
+RestartSec=10
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=docker-compose.service multi-user.target
+RequiredBy=docker-compose.service