Move grenade neutron forward job to py3 and in grenade repo

'legacy-grenade-dsvm-neutron-forward' grenade neutron forward jobs
is present in opensatck-zuul-jobs repo running on python 2. This needs
to run on py3 from Ussuri onwards and py2 for stable/branch.

py2 version has been kept in opensatck-zuul-jobs and for ussuri
onwwards this has been migrated to grenade repo with py3 version.

Change-Id: Ifebd2492b9af322661c18a17c3724940d065c2b5

.zuul.yaml

@@ -11,6 +11,23 @@
       - ^.*\.rst$
       - ^doc/.*$
 
+- job:
+    name: grenade-dsvm-neutron-forward
+    # Old name: grenade-dsvm-neutron-forward
+    parent: legacy-dsvm-base
+    # This is py3 version for ussuri onwards rest all branch needs to be py2
+    # version which is present in openstack-zuul-jobs.
+    # We need to take care of this branch variant and python version while
+    # migrating these jobs to zuulv3.
+    branches: ^(?!(stable/(ocata|pike|queens|rocky|stein|train))).*$
+    run: playbooks/legacy/grenade-dsvm-neutron-forward/run.yaml
+    post-run: playbooks/legacy/grenade-dsvm-neutron-forward/post.yaml
+    timeout: 10800
+    required-projects:
+      - openstack/grenade
+      - openstack/devstack-gate
+      - openstack/neutron
+
 - job:
     name: grenade-py3
     parent: legacy-dsvm-base
@@ -48,7 +65,7 @@
     experimental:
       jobs:
         - grenade-postgresql
-        - legacy-grenade-dsvm-neutron-forward:
+        - grenade-dsvm-neutron-forward:
             irrelevant-files: *grenade-irrelevant-files
         - trove-grenade:
             irrelevant-files: *grenade-irrelevant-files

playbooks/legacy/grenade-dsvm-neutron-forward/post.yaml

@@ -0,0 +1,15 @@
+- hosts: primary
+  tasks:
+
+    - name: Copy files from {{ ansible_user_dir }}/workspace/ on node
+      synchronize:
+        src: '{{ ansible_user_dir }}/workspace/'
+        dest: '{{ zuul.executor.log_root }}'
+        mode: pull
+        copy_links: true
+        verify_host: true
+        rsync_opts:
+          - --include=/logs/**
+          - --include=*/
+          - --exclude=*
+          - --prune-empty-dirs

playbooks/legacy/grenade-dsvm-neutron-forward/run.yaml

@@ -0,0 +1,43 @@
+- hosts: all
+  name: Autoconverted job legacy-grenade-dsvm-neutron-forward from old job gate-grenade-dsvm-neutron-forward-ubuntu-xenial
+  tasks:
+
+    - name: Ensure legacy workspace directory
+      file:
+        path: '{{ ansible_user_dir }}/workspace'
+        state: directory
+
+    - shell:
+        cmd: |
+          set -e
+          set -x
+          cat > clonemap.yaml << EOF
+          clonemap:
+            - name: openstack/devstack-gate
+              dest: devstack-gate
+          EOF
+          /usr/zuul-env/bin/zuul-cloner -m clonemap.yaml --cache-dir /opt/git \
+              https://opendev.org \
+              openstack/devstack-gate
+        executable: /bin/bash
+        chdir: '{{ ansible_user_dir }}/workspace'
+      environment: '{{ zuul | zuul_legacy_vars }}'
+
+    - shell:
+        cmd: |
+          set -e
+          set -x
+          export PROJECTS="openstack/grenade $PROJECTS"
+          export PYTHONUNBUFFERED=true
+          export DEVSTACK_GATE_TEMPEST=1
+          export DEVSTACK_GATE_GRENADE=forward
+          export DEVSTACK_GATE_NEUTRON=1
+          export BRANCH_OVERRIDE=default
+          if [ "$BRANCH_OVERRIDE" != "default" ] ; then
+              export OVERRIDE_ZUUL_BRANCH=$BRANCH_OVERRIDE
+          fi
+          cp devstack-gate/devstack-vm-gate-wrap.sh ./safe-devstack-vm-gate-wrap.sh
+          ./safe-devstack-vm-gate-wrap.sh
+        executable: /bin/bash
+        chdir: '{{ ansible_user_dir }}/workspace'
+      environment: '{{ zuul | zuul_legacy_vars }}'