checkbox remote did not use env var DISPLAY

[Taihsiang Ho]

The recent desktop sru jobs failed as a false alarm like this one

camera/multiple-resolution-images_video0

No protocol specified
Unable to init server: Could not connect: Connection refused
No protocol specified
Unable to init server: Could not connect: Connection refused
No protocol specified
Unable to init server: Could not connect: Connection refused

(camera_test:8297): Clutter-CRITICAL **: 06:35:32.231: Unable to initialize Clutter: Could not initialize Gdk
No protocol specified
Unable to init server: Could not connect: Connection refused

(camera_test:8297): Gtk-WARNING **: 06:35:32.231: cannot open display: :0

from
http://10.101.50.238:8080/job/cert-stock-sru-bionic-desktop-201606-22344/181/ and https://certification.canonical.com/hardware/201606-22344/submission/153352/

I figured out it is because that way we enable checkbox slave differs for this merge request https://code.launchpad.net/~sylvain-pineau/checkbox-ng/+git/packaging_remote_service/+merge/373394

The merge request makes the slave process will be started by root rather than a typical user (e.g. ubuntu for desktop sru jobs)

[More Information]

By specifying User=ubuntu in [Service] session we could fix this issue for desktop. However it may be not a good solution because the user name will differ in the other jenkins jobs.

[Taihsiang Ho (tai271828)]

As a short term workaround, we could update the systemd file and reload/restart the corresponding service without touching checkbox-ng source.

[Sylvain Pineau (sylvain-pineau)]

Our plan about remote is to run the service as root at switch to a normal user on demand, this way needless to setup a sudoer rule. Stopping the service and running it as ubuntu user is a short term solution.

For the long term, I'll propose a fix to set DISPLAY when there's actually a desktop session running (unity or gnome).

[Taihsiang Ho (tai271828)]

Implementation of the workaround https://code.launchpad.net/~taihsiangho/hwcert-jenkins-jobs/+git/hwcert-jenkins-jobs/+merge/374787

[Sylvain Pineau (sylvain-pineau)]

@Tai, please try to set the normal user to ubuntu in your launcher:

https://checkbox.readthedocs.io/en/latest/launcher-tutorial.html#daemon-specific-configuration

It will be a prerequisite for the DISPLAY fix

[Taihsiang Ho (tai271828)]

The merge request has a regression:

Application Malfunction Detected

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/guacamole/core.py", line 248, in eat
    return self._dispatch()
  File "/usr/lib/python3/dist-packages/guacamole/core.py", line 298, in _dispatch
    result = ingredient.dispatch(self.context)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 152, in dispatch
    return self._dispatch(context, 0)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 179, in _dispatch
    return self._dispatch_None(context, level, retval, command)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 208, in _dispatch_None
    return self._dispatch(context, level + 1)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 165, in _dispatch
    retval = command.invoked(context)
  File "/usr/lib/python3/dist-packages/checkbox_ng/launcher/master.py", line 141, in invoked
    self.connect_and_run(ctx.args.host, port)
  File "/usr/lib/python3/dist-packages/checkbox_ng/launcher/master.py", line 198, in connect_and_run
    }[state]()
  File "/usr/lib/python3/dist-packages/checkbox_ng/launcher/master.py", line 221, in new_session
    tps = self.sa.start_session(configuration)
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/netref.py", line 199, in __call__
    return syncreq(_self, consts.HANDLE_CALL, args, kwargs)
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/netref.py", line 75, in syncreq
    return conn.sync_request(handler, proxy, *args)
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/protocol.py", line 471, in sync_request
    return self.async_request(handler, *args, timeout=timeout).value
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/async_.py", line 97, in value
    raise self._obj
plainbox.vendor.rpyc.core.vinegar/psutil._exceptions._get_exception_class.<locals>.Derived: None

========= Remote Traceback (1) =========
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/psutil/_pslinux.py", line 1390, in wrapper
    return fun(self, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/psutil/_pslinux.py", line 1512, in environ
    with open_text("%s/%s/environ" % (self._procfs_path, self.pi...

[Taihsiang Ho (tai271828)]

may* have. Let me dive into it a bit, e.g. to see if the normal_user is assigned correctly.

[Sylvain Pineau (sylvain-pineau)]

This permission error, are you sure you're running the service via systemd? I mean the one that that deb package installs? You should not start one yourself now (i.e from the ubuntu user session)

[Taihsiang Ho (tai271828)]

The latest run looks good now.

[Taihsiang Ho (tai271828)]

The job running on bionic is good. However, the psutil version on Xenial seems not compatible

                        Application Malfunction Detected

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/guacamole/core.py", line 248, in eat
    return self._dispatch()
  File "/usr/lib/python3/dist-packages/guacamole/core.py", line 298, in _dispatch
    result = ingredient.dispatch(self.context)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 152, in dispatch
    return self._dispatch(context, 0)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 179, in _dispatch
    return self._dispatch_None(context, level, retval, command)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 208, in _dispatch_None
    return self._dispatch(context, level + 1)
  File "/usr/lib/python3/dist-packages/guacamole/ingredients/cmdtree.py", line 165, in _dispatch
    retval = command.invoked(context)
  File "/usr/lib/python3/dist-packages/checkbox_ng/launcher/master.py", line 141, in invoked
    self.connect_and_run(ctx.args.host, port)
  File "/usr/lib/python3/dist-packages/checkbox_ng/launcher/master.py", line 198, in connect_and_run
    }[state]()
  File "/usr/lib/python3/dist-packages/checkbox_ng/launcher/master.py", line 221, in new_session
    tps = self.sa.start_session(configuration)
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/netref.py", line 199, in __call__
    return syncreq(_self, consts.HANDLE_CALL, args, kwargs)
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/netref.py", line 75, in syncreq
    return conn.sync_request(handler, proxy, *args)
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/protocol.py", line 471, in sync_request
    return self.async_request(handler, *args, timeout=timeout).value
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/async_.py", line 97, in value
    raise self._obj
_get_exception_class.<locals>.Derived: 'Process' object has no attribute 'environ'

========= Remote Traceback (1) =========
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/plainbox/vendor/rpyc/core/protocol.py", line 329, in _dispatch_request
    res = self._HANDLERS[handler](self, *args)
  File "/usr/lib/python3/dist-packages/plainbox/v...