[train][goal] Define new tricircle-functional-ipv6-only job

As part of Train community goal 'Support IPv6-Only Deployments and Testing'[1],
Tempest has defined the base job 'legacy-dsvm-base-ipv6-only'
which will deploy services on IPv6.

This commit adds the new job 'tricircle-functional-ipv6-only'
run on gate which is derived from 'legacy-dsvm-base-ipv6-only'.

Verification structure will be:
- 'legacy-dsvm-base-ipv6-only' deploy the service on IPv6 and
  verify the IPv6-only setting and listen address
- 'tricircle-functional-ipv6-only' will run the tests.

Story: #2005477
Task: #35935

[1] https://governance.openstack.org/tc/goals/train/ipv6-support-and-testing.html

Change-Id: I5f430b4ae7690ae80d8a640b3706337036778029

.zuul.yaml

@@ -25,6 +25,11 @@
       devstack_localrc:
         USE_PYTHON3: true
 
+- job:
+    name: tricircle-functional-ipv6-only
+    parent: tricircle-functional-python3
+    run: playbooks/tricircle-dsvm-functional/run-ipv6.yaml
+
 - job:
     name: tricircle-multiregion
     parent: legacy-dsvm-base-multinode
@@ -77,6 +82,7 @@
               - openstack/networking-sfc
         - tricircle-functional
         - tricircle-functional-python3
+        - tricircle-functional-ipv6-only
         - tricircle-multiregion
     gate:
       jobs:
@@ -94,4 +100,5 @@
               - openstack/neutron
               - openstack/networking-sfc
         - tricircle-functional
+        - tricircle-functional-ipv6-only
         - tricircle-multiregion

playbooks/tricircle-dsvm-functional/run-ipv6.yaml

@@ -0,0 +1,77 @@
+- hosts: all
+  name: legacy-tricircle-dsvm-functional version with IPv6
+  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
+          cat << 'EOF' >>"/tmp/dg-local.conf"
+          [[local|localrc]]
+          enable_plugin tricircle https://opendev.org/openstack/tricircle
+
+          EOF
+        executable: /bin/bash
+        chdir: '{{ ansible_user_dir }}/workspace'
+      environment: '{{ zuul | zuul_legacy_vars }}'
+
+    - shell:
+        cmd: |
+          set -e
+          set -x
+          export PYTHONUNBUFFERED=true
+          export BRANCH_OVERRIDE=default
+          export PROJECTS="openstack/tricircle openstack/neutron openstack/networking-sfc $PROJECTS"
+          export LIBS_FROM_GIT="neutron,networking-sfc"
+          export DEVSTACK_GATE_NEUTRON=1
+          export DEVSTACK_GATE_TEMPEST=0
+          export DEVSTACK_GATE_TEMPEST_ALL_PLUGINS=0
+          export DEVSTACK_GATE_TEMPEST_REGEX="tricircle.tempestplugin"
+          export DEVSTACK_LOCAL_CONFIG+=$'\n'"SERVICE_IP_VERSION=6"
+          export DEVSTACK_LOCAL_CONFIG+=$'\n'"SERVICE_HOST=''"
+          export DEVSTACK_LOCAL_CONFIG+=$'\n'"USE_PYTHON3=true"
+
+          if [ "$BRANCH_OVERRIDE" != "default" ] ; then
+              export OVERRIDE_ZUUL_BRANCH=$BRANCH_OVERRIDE
+          fi
+
+          function pre_test_hook {
+              cd /opt/stack/new/tricircle/tricircle/tempestplugin/
+              ./pre_test_hook.sh
+          }
+          export -f pre_test_hook
+
+          function post_test_hook {
+              cd $BASE/new/tempest/tools
+              ./verify-ipv6-only-deployments.sh
+              cd /opt/stack/new/tricircle/tricircle/tempestplugin/
+              ./post_test_hook.sh
+          }
+          export -f post_test_hook
+
+          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 }}'