[PATCH] tbot_contrib/utils.py: collect some usefull linux utils

[Heiko Schocher]

Hello Harald,

Am 20.04.2020 um 17:41 schrieb Harald Seiler:
> Hello Heiko,
> 
> thanks for the patch, this is quite useful!
> 
> On Mon, 2020-04-20 at 15:03 +0200, Heiko Schocher wrote:
>> collect usefull linux utils functions. Start with
>>
>> check_systemd_services_running(lnx: linux.LinuxShell, services: list)
> 
> Can we shorten the name a bit?  I'd suggest something like
> `ensure_running` although feel free to use something else if you have
> a better idea ...

Hmm.. hard to say. I think systemd should be in the name too.

ensure_sysd_service_run
ensure_sysd_job_run
check_sysd_job_run

> 
>> check if all systemd services in list services run on linux
>> machine lnx. If not, try to start them.
>>
>> Signed-off-by: Heiko Schocher <hs at denx.de>
>> ---
>>
>>   tbot_contrib/utils.py | 31 +++++++++++++++++++++++++++++++
>>   1 file changed, 31 insertions(+)
>>   create mode 100644 tbot_contrib/utils.py
>>
>> diff --git a/tbot_contrib/utils.py b/tbot_contrib/utils.py
>> new file mode 100644
>> index 0000000..8073f89
>> --- /dev/null
>> +++ b/tbot_contrib/utils.py
>> @@ -0,0 +1,31 @@
>> +# tbot, Embedded Automation Tool
>> +# Copyright (C) 2020  Harald Seiler
> 
> I guess this shouldn't be me ;)

Heh, fast copy and paste ...

Hmm.. what about using SPDX License identifier ?

>> +#
>> +# This program is free software: you can redistribute it and/or modify
>> +# it under the terms of the GNU General Public License as published by
>> +# the Free Software Foundation, either version 3 of the License, or
>> +# (at your option) any later version.
>> +#
>> +# This program is distributed in the hope that it will be useful,
>> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> +# GNU General Public License for more details.
>> +#
>> +# You should have received a copy of the GNU General Public License
>> +# along with this program.  If not, see <https://www.gnu.org/licenses/>;;.
>> +
>> +from tbot.machine import linux
>> +
>> +
>> +def check_systemd_services_running(lnx: linux.LinuxShell, services: list) -> None:
> 
> The correct type-annotation for services would be `typing.List[str]`.
> You'll also need to import the typing module for that.

changed.

>> +    """
>> +    check if all systemd services in list services run on linux machine lnx.
>> +    If not, try to start them.
>> +
>> +    :param lnx: linux shell
>> +    :param services: list of systemd services
>> +    """
>> +    for s in services:
>> +        ret = lnx.exec("systemctl", "status", s, "--no-pager")
>> +        if ret[0] != 0:
> 
> I think it is more robust to use `systemctl is-active` for this check.
> Also, you can use `lnx.test()` which makes this a bit more concise:
> 
>      if lnx.test("systemctl", "is-active", s):
> 

Thanks to Wolfgang for his reply, we found this ... I would say bug...
yesterday, so "systemctl status" seems correct to me.

>> +            lnx.test("sudo", "systemctl", "start", s)
> 
> This one should be lnx.exec0().  test() will not raise an excepion in case
> of an error so failure to start the unit would not be noticed.

Huh, than I msiunderstood you yesterday, fixed.

Thanks for the review. I send v2 if we solved the naming.

bye,
Heiko
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