Add gate for py3k compilance on fm-rest-api

Alot of work has gone into making sure that starlingx is python3
compatibity. To ensure that we remain python3 compatible add a pylint
gate that runs with the --py3k argument to check for possible python3
syntax erorrs.

Story: 2006796
Task: 43102
Signed-off-by: Bernardo Decco de Siqueira <bernardo.deccodesiqueira@windriver.com>
Change-Id: I1275e8d1d0fd0d9e998a29a67372de4ed78a2c7d

.zuul.yaml

@@ -15,6 +15,7 @@
         - stx-fault-build
         - fault-rest-api-py27
         - fault-rest-api-py36
+        - fault-rest-api-py3k
     gate:
       jobs:
         - openstack-tox-linters
@@ -22,6 +23,7 @@
         - fault-tox-pylint
         - fault-rest-api-py27
         - fault-rest-api-py36
+        - fault-rest-api-py3k
     post:
       jobs:
         - stx-fault-upload-git-mirror
@@ -82,6 +84,18 @@
       tox_envlist: py36
       tox_extra_args: -c fm-rest-api/fm/tox.ini
 
+- job:
+    name: fault-rest-api-py3k
+    parent: tox
+    description: |
+      Run py3k test for fm-rest-api
+    nodeset: ubuntu-bionic
+    required-projects:
+      - starlingx/config
+    vars:
+      tox_envlist: py3k
+      tox_extra_args: -c fm-rest-api/fm/tox.ini
+
 - job:
     name: fault-tox-pylint
     parent: tox

fm-rest-api/fm/tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py36
+envlist = py27,py36,py3k
 minversion = 2.3
 skipsdist = True
 stxdir = {toxinidir}/../../../
@@ -33,6 +33,16 @@ commands =
   stestr run {posargs}
   stestr slowest
 
+[testenv:py3k]
+basepython = python3
+deps = {[testenv]deps}
+       -e{toxinidir}/../../../config/tsconfig/tsconfig
+       -e{toxinidir}/../../../config/sysinv/cgts-client/cgts-client
+       -r{toxinidir}/../../requirements.txt
+       -r{toxinidir}/../../test-requirements.txt
+
+commands = pylint {posargs} --py3k --disable=W fm --rcfile=../../pylint.rc
+
 [testenv:cover]
 deps = {[testenv]deps}
        coverage

tox.ini

@@ -157,6 +157,10 @@ basepython = python3
 whitelist_externals = cat
 commands = cat /etc/fm/fm.conf
 
+[testenv:py3k]
+basepython = python3
+description = Dummy environment to allow py3k to be run in subdir tox
+
 [testenv:bandit]
 basepython = python3
 description = Bandit code scan for *.py files under config folder