commit	3de9698dae2d251cba482d4ccc78d58d2a02d564	[log] [tgz]
author	George Liu <liuxiwei@inspur.com>	Tue May 26 10:42:53 2020 +0800
committer	George Liu <liuxiwei@inspur.com>	Tue May 26 11:06:08 2020 +0800
tree	1cbfbff0e15907c66525520d893deb0afbf7b050
parent	3c2f44962c163668272c473ddfb9c35bf8774570 [diff]

tree: 1cbfbff0e15907c66525520d893deb0afbf7b050

README.md

Introduction

phosphor-time-manager is the time manager service that implements D-Bus interface xyz/openbmc_project/Time/EpochTime.interface.yaml. The user can get or set the BMC's time via this interface.

General usage

The service xyz.openbmc_project.Time.Manager provides an object on D-Bus:

/xyz/openbmc_project/time/bmc

where each object implements interface xyz.openbmc_project.Time.EpochTime.

The user can directly get or set the property Elapsed of the objects to get or set the time. For example on an authenticated session:

To get BMC's time:

### With busctl on BMC
busctl get-property xyz.openbmc_project.Time.Manager \
    /xyz/openbmc_project/time/bmc xyz.openbmc_project.Time.EpochTime Elapsed

### With REST API on remote host
curl -b cjar -k https://${BMC_IP}/xyz/openbmc_project/time/bmc

To set BMC's time:

### With busctl on BMC
busctl set-property xyz.openbmc_project.Time.Manager \
    /xyz/openbmc_project/time/bmc xyz.openbmc_project.Time.EpochTime \
    Elapsed t <value-in-microseconds>

### With REST API on remote host
curl -b cjar -k -H "Content-Type: application/json" -X PUT \
    -d '{"data": 1487304700000000}' \
    https://${BMC_IP}/xyz/openbmc_project/time/bmc/attr/Elapsed

Time settings

Getting BMC time is always allowed, but setting the time may not be allowed depending on the below two settings in the settings manager.

TimeSyncMethod
- NTP: The time is set via NTP server.
- MANUAL: The time is set manually.

A summary of which cases the time can be set on BMC or HOST:

Mode	Set BMC Time
NTP	Fail to set
MANUAL	OK

To set an NTP server:

### With busctl on BMC
busctl set-property  xyz.openbmc_project.Network \
   /xyz/openbmc_project/network/eth0 \
   xyz.openbmc_project.Network.EthernetInterface NTPServers \
   as 1 "<ntp_server>"

### With REST API on remote host
curl -c cjar -b cjar -k -H "Content-Type: application/json" -X  PUT  -d \
    '{"data": ["<ntp_server>"] }' \
    https://${BMC_IP}/xyz/openbmc_project/network/eth0/attr/NTPServers

To go into NTP mode

### With busctl on BMC
busctl set-property xyz.openbmc_project.Settings \
    /xyz/openbmc_project/time/sync_method xyz.openbmc_project.Time.Synchronization \
    TimeSyncMethod s "xyz.openbmc_project.Time.Synchronization.Method.NTP"

### With REST API on remote host
curl -c cjar -b cjar -k -H "Content-Type: application/json" -X  PUT  -d \
    '{"data": "xyz.openbmc_project.Time.Synchronization.Method.NTP" }' \
    https://${BMC_IP}/xyz/openbmc_project/time/sync_method/attr/TimeSyncMethod

Special note on changing NTP setting

Starting from OpenBMC 2.6 (with systemd v239), systemd's timedated introduces a new beahvior that it checks the NTP services' status during setting time, instead of checking the NTP setting:

When NTP server is set to disabled, and the NTP service is stopping but not stopped, setting time will get an error.

In OpenBMC 2.4 (with systemd v236), the above will always succeed.

This results in openbmc/openbmc#3459, and the related test cases are updated to cooperate with this behavior change.

Special note on host on

When the host is on, the changes of the above time mode are not applied but deferred. The changes of the mode are saved to persistent storage.

When the host is off, the saved mode are read from persistent storage and are applied.

Note: A user can set the time mode in the settings daemon at any time, but the time manager applying them is governed by the above condition.