migrate testing to ubuntu focal

As per victoria cycle testing runtime and community goal
we need to migrate upstream CI/CD to Ubuntu Focal(20.04).

keeping few jobs running on bionic nodeset till
https://storyboard.openstack.org/#!/story/2008185 is fixed
otherwise base devstack jobs switching to Focal will block
the gate.

Change-Id: I1106c5c2b400e7db899959550eb1dc92577b319d
Story: #2007865
Task: #40188

devstack/lib/ironic

@@ -1022,9 +1022,7 @@ function cleanup_redfish {
 function install_redfish {
     # TODO(lucasagomes): Use Apache WSGI instead of gunicorn
 
-    if is_ubuntu; then
+    if is_fedora; then
-        install_package gunicorn3
-    elif is_fedora; then
         install_package python3-gunicorn
     else
         pip_install_gr "gunicorn"
@@ -1039,7 +1037,7 @@ function install_redfish {
 
     local cmd
 
-    cmd=$(which gunicorn3)
+    cmd=$(which gunicorn)
     cmd+=" sushy_tools.emulator.main:app"
     cmd+=" --bind ${HOST_IP}:${IRONIC_REDFISH_EMULATOR_PORT}"
     cmd+=" --env FLASK_DEBUG=1"

zuul.d/ironic-jobs.yaml

@@ -3,7 +3,7 @@
     abstract: true
     description: Base job for devstack/tempest based ironic jobs.
     parent: devstack-tempest
-    nodeset: openstack-single-node-bionic
+    nodeset: openstack-single-node-focal
     post-run: playbooks/ci-workarounds/get_tftpd.yaml
     timeout: 10800
     required-projects:
@@ -222,6 +222,12 @@
     name: ironic-tempest-partition-uefi-redfish-vmedia
     description: "Deploy ironic node over Redfish virtual media using UEFI boot mode"
     parent: ironic-tempest-partition-bios-redfish-pxe
+    # TODO: Remove the below nodeset setting to Bionic once
+    # https://storyboard.openstack.org/#!/story/2008185 is fixed
+    # Once nodeset is removed form here then devstack base jobs
+    # will automatically run this job on Ubuntu Focal nodeset from
+    # Victoria gate onwards.
+    nodeset: openstack-single-node-bionic
     vars:
       devstack_localrc:
         IRONIC_BOOT_MODE: uefi
@@ -312,7 +318,6 @@
     name: ironic-tempest-ipa-partition-uefi-pxe_ipmitool
     description: ironic-tempest-ipa-partition-uefi-pxe_ipmitool
     parent: ironic-base
-    nodeset: openstack-single-node-focal
     vars:
       devstack_localrc:
         IRONIC_BOOT_MODE: uefi
@@ -324,6 +329,12 @@
     name: ironic-tempest-ipa-partition-pxe_ipmitool
     description: ironic-tempest-ipa-partition-pxe_ipmitool that also tests cleaning.
     parent: ironic-base
+    # TODO: Remove the below nodeset setting to Bionic once
+    # https://storyboard.openstack.org/#!/story/2008185 is fixed
+    # Once nodeset is removed form here then devstack base jobs
+    # will automatically run this job on Ubuntu Focal nodeset from
+    # Victoria gate onwards.
+    nodeset: openstack-single-node-bionic
     vars:
       devstack_localrc:
         IRONIC_DEFAULT_BOOT_OPTION: netboot
@@ -606,7 +617,6 @@
     name: ironic-tempest-ipa-partition-uefi-pxe-grub2
     description: Ironic tempest scenario test utilizing PXE, UEFI, and Grub2
     parent: ironic-base
-    nodeset: openstack-single-node-focal
     vars:
       devstack_localrc:
         IRONIC_ENABLED_HARDWARE_TYPES: ipmi
@@ -724,6 +734,12 @@
     name: ironic-tempest-bios-ipmi-direct-tinyipa
     description: ironic-tempest-wholedisk-bios-ipmi-direct-tinyipa that also tests cleaning.
     parent: ironic-base
+    # TODO: Remove the below nodeset setting to Bionic once
+    # https://storyboard.openstack.org/#!/story/2008185 is fixed
+    # Once nodeset is removed form here then devstack base jobs
+    # will automatically run this job on Ubuntu Focal nodeset from
+    # Victoria gate onwards.
+    nodeset: openstack-single-node-bionic
     vars:
       devstack_localrc:
         IRONIC_DEFAULT_RESCUE_INTERFACE: agent