[systemd-devel] Variables in the [Unit] section of a server

[Steve Dickson]

On 01/23/2016 11:33 AM, Armin K. wrote:
> On 23.01.2016 17:28, Armin K. wrote:
>>> On 01/13/2016 10:51 AM, Steve Dickson wrote:
>>>> Hello,
>>>>
>>>> Is is possible to set a variable in the [Unit]
>>>> section of a service?
>>>>
>>>> For example in rpc-gssd.service there is
>>>>     ConditionPathExists=/etc/krb5.keytab
>>>>
>>>> but for some installation the krb5.keytab
>>>> is in a different place. The rpc.gssd daemon
>>>> can be told this by setting a command line
>>>> argument from the EnvironmentFile.
>>>>
>>>> So people have to edit both the EnvironmentFile
>>>> and the rpc-gssd.service to make this change. 
>>>>
>>>> So it would be nice if only the EnvironmentFile
>>>> need to be edit and the change would happen
>>>> in both places. 
>>>>
>>>> Possible?
>>>>
>>>> steved.
>>
>> I'm sorry I'm not responding to the original mail, as I just subscribed
>> yesterday to this list.
>>
>> I am not sure I fully understand what you want, but I think this might do it:
>>
>> [Unit]
>> Description=test
>>
>> [Service]
>> Type=oneshot
>> Environment=TEST=blah
>> EnvironmentFile=-/etc/systemd/system/test-env
>> ExecStart=/etc/systemd/system/test ${TEST}
>> TimeoutSec=0
>> RemainAfterExit=yes
>>
>> The /etc/systemd/system/test is a script that prints $1, depending on what is
>> being passed to it. When env file is not present, it prints the TEST from the
>> unit file. When env file is present, and TEST is set to something else, it
>> prints its value. Is that what you are looking for?
>>
>> Cheers
>>
> 
> Ugh, sorry. You asked for the [Unit] section, not the [Service] section.
> From what I see, it doesn't yet seem to be possible:
> 
> [/etc/systemd/system/test.service:2] Unknown lvalue 'Environment' in section 'Unit'
> [/etc/systemd/system/test.service:4] Path in condition not absolute, ignoring: $TEST
> 
> You can always use some kind of hackery in ExecStartPre, but I don't think that's
> what anyone wants.
> 
Well its to bad ConditionPathExists is not part of the [Service] section
so I could use a shell variable... 

steved.