DnsServers using get_attr

Nameservers are configured on the ctlplane subnets by the
undercloud installer, the nameservers are used early during
the deployment, prior to running os-net-config.

Remove the default DnsServer's in THT, replacing it with
an empty list and use get_attr to get the values for
DnsServers for the overcloud from the ctlplane subnet(s).

A conditinal is used in  puppet/role.role.j2.yaml so that
the parameter value is used whenever it is not [] (default)
to provide backwards compatibilityi and in case the user
want to use different DnsServers for the overcloud and
undercloud.

Partial: blueprint tripleo-routed-networks-templates
Change-Id: I5f33e06ca3f4b13cc355e02156edd9d8a1f773cd

ci/common/net-config-multinode-os-net-config.yaml

@@ -52,6 +52,13 @@ parameters:
     default: 1300
     description: The mtu of the OvS bridge
     type: number
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
   EC2MetadataIp:
     default: ''
     description: The IP address of the EC2 metadata server. (The parameter

ci/common/net-config-multinode.yaml

@@ -48,6 +48,13 @@ parameters:
     description: The default route of the control plane network. (The parameter
       is automatically resolved from the ctlplane subnet's gateway_ip attribute.)
     type: string
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
   EC2MetadataIp:
     default: ''
     description: The IP address of the EC2 metadata server. (The parameter

ci/common/net-config-simple-bridge.yaml

@@ -41,6 +41,13 @@ parameters:
     default: ''
     description: IP address/subnet on the management network
     type: string
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
   EC2MetadataIp:
     default: ''
     description: The IP address of the EC2 metadata server. (The parameter

ci/environments/network/multiple-nics-ipv6/network-environment.yaml

@@ -18,4 +18,3 @@ parameter_defaults:
   StorageMgmtAllocationPools: [{"start": "fd00:fd00:fd00:4000::10", "end": "fd00:fd00:fd00:4000:ffff:ffff:ffff:fffe"}]
   TenantNetCidr: 172.16.0.0/24
   TenantAllocationPools: [{"start": "172.16.0.10", "end": "172.16.0.250"}]
-  DnsServers: ["8.8.8.8", "8.8.4.4"]

ci/environments/network/multiple-nics-ipv6/nic-configs/ceph-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics-ipv6/nic-configs/cinder-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics-ipv6/nic-configs/compute.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics-ipv6/nic-configs/controller.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics-ipv6/nic-configs/swift-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics/network-environment.yaml

@@ -19,4 +19,3 @@ parameter_defaults:
   StorageMgmtAllocationPools: [{"start": "172.19.0.10", "end": "172.19.0.250"}]
   TenantNetCidr: 172.16.0.0/24
   TenantAllocationPools: [{"start": "172.16.0.10", "end": "172.16.0.250"}]
-  DnsServers: ["8.8.8.8", "8.8.4.4"]

ci/environments/network/multiple-nics/nic-configs/ceph-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics/nic-configs/cinder-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics/nic-configs/compute.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics/nic-configs/controller.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/multiple-nics/nic-configs/swift-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/public-bond/network-environment.yaml

@@ -18,5 +18,4 @@ parameter_defaults:
   StorageMgmtAllocationPools: [{"start": "172.19.0.10", "end": "172.19.0.250"}]
   TenantNetCidr: 172.16.0.0/24
   TenantAllocationPools: [{"start": "172.16.0.10", "end": "172.16.0.250"}]
-  DnsServers: ["8.8.8.8", "8.8.4.4"]
   BondInterfaceOvsOptions: bond_mode=balance-slb

ci/environments/network/public-bond/nic-configs/ceph-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/public-bond/nic-configs/cinder-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/public-bond/nic-configs/compute.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/public-bond/nic-configs/controller.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

ci/environments/network/public-bond/nic-configs/swift-storage.yaml

@@ -75,7 +75,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

environments/composable-roles/monolithic-ha.yaml

@@ -37,9 +37,9 @@ parameter_defaults:
   # Type: string
   ControllerHostnameFormat: '%stackname%-controller-%index%'
 
-  # DNS servers to use for the Overcloud
+  # DNS servers to use for the Overcloud (2 max for some implementations). If not set the nameservers configured in the ctlplane subnet(s) on the undercloud will be used.
   # Type: comma_delimited_list
-  DnsServers: ['8.8.8.8', '8,8.4.4']
+  DnsServers: []
 
   # NTP servers list. Defaulted to pool.ntp.org in order to have a sane default for Pacemaker deployments when not configuring this parameter by default.
   # Type: comma_delimited_list

environments/composable-roles/monolithic-nonha.yaml

@@ -37,9 +37,9 @@ parameter_defaults:
   # Type: string
   ControllerHostnameFormat: '%stackname%-controller-%index%'
 
-  # DNS servers to use for the Overcloud
+  # DNS servers to use for the Overcloud (2 max for some implementations). If not set the nameservers configured in the ctlplane subnet(s) on the undercloud will be used.
   # Type: comma_delimited_list
-  DnsServers: ['8.8.8.8', '8,8.4.4']
+  DnsServers: []
 
   # NTP servers list. Defaulted to pool.ntp.org in order to have a sane default for Pacemaker deployments when not configuring this parameter by default.
   # Type: comma_delimited_list

environments/composable-roles/standalone.yaml

@@ -42,9 +42,9 @@ parameter_defaults:
   # Type: number
   DatabaseCount: 3
 
-  # DNS servers to use for the Overcloud
+  # DNS servers to use for the Overcloud (2 max for some implementations). If not set the nameservers configured in the ctlplane subnet(s) on the undercloud will be used.
   # Type: comma_delimited_list
-  DnsServers: ['8.8.8.8', '8,8.4.4']
+  DnsServers: []
 
   # Number of Messaging nodes
   # Type: number

environments/network-environment-v6.j2.yaml

@@ -55,7 +55,9 @@ parameter_defaults:
 {% endfor %}
 {#- FIXME: These global parameters should be defined in a YAML file, e.g. network_data.yaml. #}
   # Define the DNS servers (maximum 2) for the overcloud nodes
-  DnsServers: ["8.8.8.8","8.8.4.4"]
+  # When the list is not set (empty) the nameservers on the ctlplane subnet(s) will be used.
+  # (ctlplane subnet(s) nameservers are confgured by the ``undercloud_nameservers`` option in ``undercloud.conf``)
+  DnsServers: []
   # List of Neutron network types for tenant networks (will be used in order)
   NeutronNetworkType: 'vxlan,vlan'
   # The tunnel type for the tenant network (vxlan or gre). Set to '' to disable tunneling.

environments/network-environment.j2.yaml

@@ -53,7 +53,9 @@ parameter_defaults:
 {% endfor %}
 {#- FIXME: These global parameters should be defined in a YAML file, e.g. network_data.yaml. #}
   # Define the DNS servers (maximum 2) for the overcloud nodes
-  DnsServers: ["8.8.8.8","8.8.4.4"]
+  # When the list is no set or empty, the nameservers on the ctlplane subnets will be used.
+  # (ctlplane subnets nameservers are controlled by the ``undercloud_nameservers`` option in ``undercloud.conf``)
+  DnsServers: []
   # List of Neutron network types for tenant networks (will be used in order)
   NeutronNetworkType: 'vxlan,vlan'
   # The tunnel type for the tenant network (vxlan or gre). Set to '' to disable tunneling.

extraconfig/post_deploy/undercloud_post.yaml

@@ -42,9 +42,12 @@ parameters:
     description: >
       Whether the TripleO validations are enabled.
     type: boolean
-  DnsServers: # Override this via parameter_defaults
+  DnsServers:
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   CtlplaneLocalPhysicalNetwork:
     default: ctlplane

net-config-bond.j2.yaml

@@ -27,6 +27,13 @@ parameters:
     description: The default route of the control plane network. (The parameter
       is automatically resolved from the ctlplane subnet's gateway_ip attribute.)
     type: string
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
   EC2MetadataIp: # Here for compatability, not used.
     default: ''
     description: The IP address of the EC2 metadata server. (The parameter

net-config-bridge.j2.yaml

@@ -17,6 +17,13 @@ parameters:
     description: The default route of the control plane network. (The parameter
       is automatically resolved from the ctlplane subnet's gateway_ip attribute.)
     type: string
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
   EC2MetadataIp: # Here for compatability, not used.
     default: ''
     description: The IP address of the EC2 metadata server. (The parameter

net-config-linux-bridge.j2.yaml

@@ -23,6 +23,13 @@ parameters:
       The subnet CIDR of the control plane network. (The parameter is
       automatically resolved from the ctlplane subnet's cidr attribute.)
     type: string
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
   EC2MetadataIp:
     default: ''
     description: The IP address of the EC2 metadata server. (The parameter

net-config-noop.j2.yaml

@@ -20,6 +20,13 @@ parameters:
     description: The default route of the control plane network. (The parameter
       is automatically resolved from the ctlplane subnet's gateway_ip attribute.)
     type: string
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
   EC2MetadataIp: # Here for compatability, not used.
     default: ''
     description: The IP address of the EC2 metadata server. (The parameter

net-config-standalone.j2.yaml

@@ -30,7 +30,10 @@ parameters:
     type: json
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   InterfaceLocalMtu: # Override this via parameter_defaults
     default: 1500

net-config-static-bridge-with-external-dhcp.j2.yaml

@@ -26,7 +26,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

net-config-static-bridge.j2.yaml

@@ -26,7 +26,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

net-config-static.j2.yaml

@@ -25,7 +25,10 @@ parameters:
     type: string
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

net-config-undercloud.j2.yaml

@@ -30,7 +30,10 @@ parameters:
     type: json
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   UndercloudLocalMtu: # Override this via parameter_defaults
     default: 1500

network/config/bond-with-vlans/controller-no-external.j2.yaml

@@ -44,7 +44,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/bond-with-vlans/controller-v6.j2.yaml

@@ -42,7 +42,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/bond-with-vlans/role.role.j2.yaml

@@ -40,7 +40,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/multiple-nics/compute-dvr.j2.yaml

@@ -42,7 +42,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/multiple-nics/controller-v6.j2.yaml

@@ -41,7 +41,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/multiple-nics/role.role.j2.yaml

@@ -40,7 +40,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/single-nic-linux-bridge-vlans/controller-v6.j2.yaml

@@ -41,7 +41,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/single-nic-linux-bridge-vlans/role.role.j2.yaml

@@ -40,7 +40,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/single-nic-vlans/controller-no-external.j2.yaml

@@ -44,7 +44,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/single-nic-vlans/controller-v6.j2.yaml

@@ -41,7 +41,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

network/config/single-nic-vlans/role.role.j2.yaml

@@ -40,7 +40,10 @@ parameters:
 {%- endfor %}
   DnsServers: # Override this via parameter_defaults
     default: []
-    description: A list of DNS servers (2 max for some implementations) that will be added to resolv.conf.
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
     type: comma_delimited_list
   EC2MetadataIp:
     default: ''

puppet/role.role.j2.yaml

@@ -260,6 +260,13 @@ parameters:
     description: The IP address of the EC2 metadata server. (The parameter
       is automatically resolved from the ctlplane subnet's host_routes attribute.)
     type: string
+  DnsServers: # Override this via parameter_defaults
+    default: []
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet's
+      dns_nameservers attribute will be used.
+    type: comma_delimited_list
 
   ServerDeletionPolicy:
     description: Whether to retain or delete servers on deletion of the stack
@@ -340,6 +347,9 @@ conditions:
   ec2metadaip_set:
     not:
       equals: [{get_param: EC2MetadataIp}, '']
+  dnsservers_set:
+    not:
+      equals: [{get_param: DnsServers}, []]
 
 resources:
   {{server_resource_name}}:
@@ -479,6 +489,11 @@ resources:
               # Return an empty string if there are no host_routes in the subnet. (Standalone and Container Undercloud)
               expression: switch($.data = null => '', $.data != null => $.data.where($.destination = "169.254.169.254/32").nexthop.first())
               data: {get_attr: [{{server_resource_name}}, addresses, ctlplane, 0, subnets, 0, host_routes]}
+      DnsServers:
+        if:
+          - dnsservers_set
+          - {get_param: DnsServers}
+          - {get_attr: [{{server_resource_name}}, addresses, ctlplane, 0, subnets, 0, dns_nameservers]}
 
   {%- for network in networks %}
       {{network.name}}IpSubnet: {get_attr: [{{network.name}}Port, ip_subnet]}

releasenotes/notes/use-subnet-attrs-dnsservers-f751ec1125a9f787.yaml

@@ -0,0 +1,24 @@
+---
+features:
+  - |
+    It is no longer a requirement to provide the parameter: ``DnsServers``
+    in the environment when deploying. Now ``get_attr`` on the server resource
+    is used to resolve the value from the ``ctlplane`` subnet's
+    ``dns_nameservers`` attribute. A conditional is used to determine if the
+    user provided the parameter in the environment. If the user provided the
+    parameter, the user provided value is used.
+upgrade:
+  - |
+    Since the the ``DnsServers`` can now be resolved from the ``ctlplane``
+    subnet(s) this parameter can be removed from the environment
+    (``network-environment.yaml``).
+
+    .. Note:: Prior to removing the parameter ensure that the property of
+              the ``ctlplane`` subnet(s) is correct. In case it is not, update
+              ``undercloud.conf`` with the correct configuration and re-run the
+              ``openstack undercloud install`` command to ensure the property
+              is set correctly.
+
+    .. Note:: ``DnsServers`` is now passed to the network config template when
+              the resource is created. Because of this the parameter must be
+              defined in the network config template, even if it is not used.

sample-env-generator/composable-roles.yaml

@@ -131,8 +131,11 @@ environments:
 # in the generated config files.
 parameters:
   DnsServers:
-    default: ['8.8.8.8', '8,8.4.4']
+    default: []
-    description: DNS servers to use for the Overcloud
+    description: >
+      DNS servers to use for the Overcloud (2 max for some implementations).
+      If not set the nameservers configured in the ctlplane subnet(s) on the
+      undercloud will be used.
     type: comma_delimited_list
   # Dynamic vars based on roles
   ControllerOpenstackCount: