Allow disabling the octavia provider

To be used to work around issues with octavia provider driver
breaking CI. By default, the octavia provider is enabled, and
this change adds the ability to disable it by setting the
following attribute:

OctaviaEnableDriverAgent: false

This is a partial backport of https://review.opendev.org/#/c/713960/
It is partial because it does not disable octavia provider driver
for any CI tests (such as scenario010-standalone.yaml)

Change-Id: If04a719052cf650502258450477713d9fe06015a
(cherry picked from commit 160e85e51b)

deployment/octavia/octavia-api-container-puppet.yaml

@@ -86,17 +86,24 @@ parameters:
     default: true
     description: Configure the nova flavor for the amphora.
     type: boolean
+  # We enable the driver agent and configure the OVN provider by default if OVN
+  # is enabled.
   NeutronMechanismDrivers:
     default: 'ovn'
     description: |
         The mechanism drivers for the Neutron tenant network.
     type: comma_delimited_list
+  OctaviaEnableDriverAgent:
+    default: true
+    description:  Set to false if the driver agent needs to be disabled for some reason.
+    type: boolean
 
 conditions:
 
   internal_tls_enabled: {equals: [{get_param: EnableInternalTLS}, true]}
   use_tls_proxy: {equals : [{get_param: EnableInternalTLS}, true]}
   is_ovn_in_neutron_mechanism_driver: {contains: ['ovn', {get_param: NeutronMechanismDrivers}]}
+  enable_driver_agent: {equals: [{get_param: OctaviaEnableDriverAgent}, true]}
 
 resources:
 
@@ -192,11 +199,19 @@ outputs:
                   "%{hiera('$NETWORK')}"
                 params:
                   $NETWORK: {get_param: [ServiceNetMap, OctaviaApiNetwork]}
-          -
-            if:
-              - is_ovn_in_neutron_mechanism_driver
-              - octavia::api::provider_drivers: 'amphora: The Octavia Amphora driver.,octavia: Deprecated alias of the Octavia Amphora driver.,ovn: Octavia OVN driver.'
-              - {}
+          - octavia::api::provider_drivers:
+              list_join:
+                - ','
+                - list_concat:
+                  - - 'amphora: The Octavia Amphora driver.'
+                    - 'octavia: Deprecated alias of the Octavia Amphora driver.'
+                  -
+                    if:
+                      - and:
+                          - is_ovn_in_neutron_mechanism_driver
+                          - enable_driver_agent
+                      - ['ovn: Octavia OVN driver.']
+                      - []
 
       service_config_settings:
         rsyslog:
@@ -324,7 +339,7 @@ outputs:
                 environment:
                   KOLLA_CONFIG_STRATEGY: COPY_ALWAYS
             - if:
-                - is_ovn_in_neutron_mechanism_driver
+                - enable_driver_agent
                 - octavia_driver_agent:
                     start_order: 2
                     image: *octavia_api_image