commit	723068069aa58423e64ad0276db3a63d8f9e4d5d	[log] [tgz]
author	Patrick Williams <patrick@stwcx.xyz>	Thu Aug 04 11:40:12 2022 -0500
committer	Patrick Williams <patrick@stwcx.xyz>	Thu Aug 04 11:40:12 2022 -0500
tree	9480b34f114612fd44a7601b6ac122bfc62e3334
parent	667563c38b5157b56625bb10182d72501458f557 [diff]

tree: 9480b34f114612fd44a7601b6ac122bfc62e3334

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.

Configuration

phosphor-time-manager is configured by setting -D flags that correspond to options in phosphor-time-manager/meson_options.txt. The option names become C++ preprocessor symbols that control which code is compiled into the program.

Compile phosphor-time-manager with default options:
```
   meson builddir
   ninja -C builddir
```

Compile phosphor-time-manager with some configurable options:

   meson builddir -Dbuildtype=minsize  -Dtests=disabled
   ninja -C buildir

Generate test coverage report:

   meson builddir -Db_coverage=true -Dtests=enabled
   ninja coverage -C builddir test

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.