Module graceful shutdown support (#255)

Provide support for SmartSwitch DPU module graceful shutdown.

Description:
Single source of truth for transitions

All components now use sonic_platform_base.module_base.ModuleBase helpers:

set_module_state_transition(db, name, transition_type)
clear_module_state_transition(db, name)
get_module_state_transition(db, name) -> dict
is_module_state_transition_timed_out(db, name, timeout_secs) -> bool
Eliminates duplicated logic and race-prone direct Redis writes.

Correct table everywhere

Standardized on CHASSIS_MODULE_TABLE (replaces CHASSIS_MODULE_INFO_TABLE).
HLD mismatch addressed in code (HLD fix tracked separately).
Ownership & lifecycle

The initiator of an operation (startup/shutdown/reboot) sets:

state_transition_in_progress=True
transition_type=<op>
transition_start_time=<utc-iso8601>
The platform (set_admin_state()) is responsible for clearing:

state_transition_in_progress=False
optionally transition_end_time=<epoch> (or similar end stamp).
CLI pre-clears only when a prior transition is timed out.

Timeouts & policy

Platform JSON path only: /usr/share/sonic/device/{plat}/platform.json; else constants.

Typical production values used:

startup: 180s, shutdown: 180s (≈ graceful_wait 60s + power 120s), reboot: 120s.
Graceful wait (e.g., waiting for “Graceful shutdown complete”) is a platform policy and implemented inside platform set_admin_state()—not in ModuleBase.

Boot behavior

chassisd on start:

Clears stale flags once (centralized sweep).
Runs set_initial_dpu_admin_state() which marks transitions via ModuleBase before calling platform set_admin_state().
Leaves clearing to the platform or to well-defined status transitions (ONLINE/OFFLINE) where appropriate.
gNOI shutdown daemon

Listens on CHASSIS_MODULE_TABLE and triggers only when:

state_transition_in_progress=True and transition_type=shutdown.
Never clears the flag (ownership stays with the platform).

Bounded RPC timeouts and robust Redis access (swsssdk/swsscommon).

CLI (config chassis modules …)

Uses ModuleBase APIs for all set/get/timeout checks.
If a previous transition is stuck, is_module_state_transition_timed_out() → auto-clear then proceed.
Sets transition at the start of startup/shutdown; platform clears on completion.
Fabric card flow retained; edits are surgical.
Redis robustness

Helpers handle both stacks (swsssdk/swsscommon); no hset(mapping=...) usage.
Consistent HGETALL/HSET paths; resilient to connector differences.
Race reduction & consistency

Centralized writes prevent multi-writer races.
All transition writes include transition_start_time; clears may add an end stamp.
Existing PCI/file-lock logic left intact; unrelated behavior unchanged.
Change scope

Minimal, targeted diffs.
No background tasks added, no broad refactors beyond transition handling.
Behavior changes are limited to making transition semantics correct and uniform across repos.
HLD: # 1991 sonic-net/SONiC#1991
sonic-platform-common: #567 sonic-net/sonic-platform-common#567
sonic-utilities: sonic-net/sonic-utilities#4031
sonic-platform-daemons: sonic-net/sonic-platform-daemons#667

How to verify it
Issue the "config chassis modules shutdown DPUx" command
Verify the DPU module is gracefully shut by checking the logs in /var/log/syslog on both NPU and DPU

Author: rameshraghupathy

data/debian/rules

@@ -20,5 +20,6 @@ override_dh_installsystemd:
 	dh_installsystemd --no-start --name=procdockerstatsd
 	dh_installsystemd --no-start --name=determine-reboot-cause
 	dh_installsystemd --no-start --name=process-reboot-cause
+	dh_installsystemd --no-start --name=gnoi-shutdown
 	dh_installsystemd $(HOST_SERVICE_OPTS) --name=sonic-hostservice
 

data/debian/sonic-host-services-data.gnoi-shutdown.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=gNOI based DPU Graceful Shutdown Daemon
+Requires=database.service
+Wants=network-online.target
+After=network-online.target database.service
+
+[Service]
+Type=simple
+ExecStartPre=/usr/bin/python3 /usr/local/bin/check_platform.py
+ExecStartPre=/bin/bash /usr/local/bin/wait-for-sonic-core.sh
+ExecStart=/usr/bin/python3 /usr/local/bin/gnoi_shutdown_daemon.py
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target

scripts/check_platform.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+"""
+Check if the current platform is a SmartSwitch NPU (not DPU).
+Exit 0 if SmartSwitch NPU, exit 1 otherwise.
+"""
+import sys
+
+def main():
+    try:
+        from sonic_py_common import device_info
+        from utilities_common.chassis import is_dpu
+
+        # Check if SmartSwitch NPU (not DPU)
+        if device_info.is_smartswitch() and not is_dpu():
+            sys.exit(0)
+        else:
+            sys.exit(1)
+    except (ImportError, AttributeError, RuntimeError) as e:
+        sys.stderr.write("check_platform failed: {}\n".format(str(e)))
+        sys.exit(1)
+
+if __name__ == "__main__":
+    main()