Validating that python3 exists is not enough criteria to execute loguserdata with python3

[Vitalii Gridnev]

On ubuntu-trusty image I faced with issue at [0] when:
 1. python3 exists;
 2. pkg_resources can't be imported in python3.

That leads to issues with completing wait conditions with following errors in cloud-init logs:

 Traceback (most recent call last):
  File "/var/lib/cloud/instance/scripts/loguserdata.py", line 32, in <module>
    import pkg_resources
 ImportError: No module named 'pkg_resources'

So, I'm suggesting to use following approach to resolve this issue: when we have to determine what python executable should be used for executing loguserdata script, then should additionally check that all requirements are on the needed place.

[0] https://github.com/openstack/heat/blob/fcf725c7b31b109c014c4a4e06ea3e1d5abb2930/heat/cloudinit/loguserdata.py#L15

Moreover, please consider back-porting fix to stable/mitaka branch also.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/360804

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/361223

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/360804
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=f95a8051ca248044cb1655b19ef22b94a2c337ff
Submitter: Jenkins
Branch: master

commit f95a8051ca248044cb1655b19ef22b94a2c337ff
Author: Vitaly Gridnev <email address hidden>
Date: Fri Aug 26 01:05:51 2016 +0300

    Validate that python3 is ready for loguserdata

    By default, ubuntu trusty images has python3 executable in
    path, but we can't use that for executing loguserdata script,
    because pkg_resources can't be imported. Now it's proposed to
    try importing pkg_resources for validating readiness of
    python3 for executing this script. If pkg_resources can't be
    imported there is no other choice except using python2.

    Change-Id: Icb4f58630016874eb40dd77590469fc5de6287e4
    Closes-bug: 1617069

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/361223
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=ed46562157d2f9983f5665394ec47d2e27aad0df
Submitter: Jenkins
Branch: stable/mitaka

commit ed46562157d2f9983f5665394ec47d2e27aad0df
Author: Vitaly Gridnev <email address hidden>
Date: Fri Aug 26 01:05:51 2016 +0300

    Validate that python3 is ready for loguserdata

    By default, ubuntu trusty images has python3 executable in
    path, but we can't use that for executing loguserdata script,
    because pkg_resources can't be imported. Now it's proposed to
    try importing pkg_resources for validating readiness of
    python3 for executing this script. If pkg_resources can't be
    imported there is no other choice except using python2.

    Change-Id: Icb4f58630016874eb40dd77590469fc5de6287e4
    Closes-bug: 1617069

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/heat 7.0.0.0b3 development milestone.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/heat 6.1.0 release.