[ovs-dev] [PATCH] rhel: Environment file option for northd service

[Russell Bryant]

On Wed, Nov 16, 2016 at 4:02 AM, Babu Shanmugam <bschanmu at redhat.com> wrote:

>
>
> On Wednesday 16 November 2016 11:45 AM, Babu Shanmugam wrote:
>
>
>
> On Tuesday 15 November 2016 08:11 PM, Russell Bryant wrote:
>
>
>
> On Tue, Nov 15, 2016 at 6:19 AM, <bschanmu at redhat.com> wrote:
>
>> From: Babu Shanmugam <bschanmu at redhat.com>
>>
>> Since the northd service starts the DB servers as well, it will be
>> better to have an environment file options in the systemd unit file for
>> northd service.
>> The environment file is expected to define NORTHD_OPTS
>> which will have additional parameters to be passed to ovn-ctl script
>> that starts ovn-northd.
>>
>> Signed-off-by: Babu Shanmugam <bschanmu at redhat.com>
>> ---
>>  rhel/usr_lib_systemd_system_ovn-northd.service | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/rhel/usr_lib_systemd_system_ovn-northd.service
>> b/rhel/usr_lib_systemd_system_ovn-northd.service
>> index 5b3b03a..12230e9 100644
>> --- a/rhel/usr_lib_systemd_system_ovn-northd.service
>> +++ b/rhel/usr_lib_systemd_system_ovn-northd.service
>> @@ -7,6 +7,7 @@ After=openvswitch.service
>>  [Service]
>>  Type=oneshot
>>  RemainAfterExit=yes
>> +EnvironmentFile=-/etc/sysconfig/ovn-northd
>>  Environment=OVS_RUNDIR=%t/openvswitch OVS_DBDIR=/var/lib/openvswitch
>> -ExecStart=/usr/share/openvswitch/scripts/ovn-ctl start_northd
>> +ExecStart=/usr/share/openvswitch/scripts/ovn-ctl start_northd
>> $NORTHD_OPTS
>>  ExecStop=/usr/share/openvswitch/scripts/ovn-ctl stop_northd
>>
>
> I'm not sure this is necessary.  I believe something close enough is
> possible with systemd already.
>
> https://fedoraproject.org/wiki/Systemd#How_do_I_
> customize_a_unit_file.2F_add_a_custom_unit_file.3F
>
> or:
>
> "Example 2. Overriding vendor settings"
> https://www.freedesktop.org/software/systemd/man/systemd.unit.html
>
> For ovn-northd, you would create a directory and config file,
> /etc/systemd/system/ovn-northd.d/local.conf, with contents like:
>
> [System]
> Environment=MY_ENV_VAR=VALUE "MY_ENV_VAR2=VALUE 2"
>
>
> Thanks for the information, Russell. This patch can be abandoned.
>
>
> I was trying to use it like you said. But, I had to override the ExecStart
> as not all the options are read from the environment variable in the
> ovn-ctl script.
> Do you think its better to add an EnvironmentFile option as proposed in
> this patch or to override ExecStart using the .conf file?
>

OK, I didn't realize that most options couldn't be specified with
environment variables.

What if we only changed the ExecStart line and then used the approach I
described to set $OVN_NORTHD_OPTS as an environment variables instead of
adding the EnvironmentFile option?

-- 
Russell Bryant