commit 98c5a48c9cc6ceeca0cba28d86f481945ac2257b
author Michael Shen <gpgpgp@google.com> Tue Sep 12 06:11:20 2023 +0000
committer Michael Shen <gpgpgp@google.com> Sat Sep 23 07:19:14 2023 +0000
tree eb3fc201e0ca53c71b5cc96e277d57194d269124
parent 4f67732ea664430a2c6f77ce18fad4787dd14e1d

boot_manager: Adding the logic to store boot time events

`boot_manager` provides a mechanism to store checkpoint and duration
separately. Every node will initiate its own `boot_manager` to record
its boot event.

Tested:
```
\# Nothing in the beginning
bmc:~# cat /usr/share/boot_time_monitor/host0_checkpoints.csv

\# Power off host
bmc:~# ipmitool chassis power off
Chassis Power Control: Down/Off

\# `ShutDownEnd` event has recoreded
bmc:~# cat /usr/share/boot_time_monitor/host0_checkpoints.csv
ShutDownEnd,1694502220905,586412450

\# Power on host
bmc:~# ipmitool chassis power on
Chassis Power Control: Up/On

\# `PowerOffEnd` event has recoreded
bmc:~# cat /usr/share/boot_time_monitor/host0_checkpoints.csv
ShutDownEnd,1694502220905,586412450
PowerOffEnd,1694502232025,586423570
```

Google-Bug-Id: 296530445
Change-Id: I3206aef646771e2ed0ca58c7a502f9fc996b155d
Signed-off-by: Michael Shen <gpgpgp@google.com>