feat: manage externaldns bind (#428)

- add module to manage externaldns bind for k8s
- add infra::dns::externaldns role
- add 198.18.19.20 as anycast for k8s external-dns service

Reviewed-on: #428

hieradata/country/au/region/syd1.yaml

@@ -5,3 +5,5 @@ profiles_dns_upstream_forwarder_unkin:
   - 198.18.19.15
 profiles_dns_upstream_forwarder_consul:
   - 198.18.19.14
+profiles_dns_upstream_forwarder_k8s:
+  - 198.18.19.20

hieradata/roles/infra/dns/externaldns.eyaml

@@ -0,0 +1,2 @@
+---
+externaldns::externaldns_key_secret: ENC[PKCS7,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]

hieradata/roles/infra/dns/externaldns.yaml

@@ -0,0 +1,65 @@
+---
+hiera_include:
+  - externaldns
+  - frrouting
+  - exporters::frr_exporter
+
+externaldns::bind_master_hostname: 'ausyd1nxvm2127.main.unkin.net'
+externaldns::k8s_zones:
+  - 'k8s.syd1.au.unkin.net'
+  - '200.18.198.in-addr.arpa'
+externaldns::slave_servers:
+  - 'ausyd1nxvm2128.main.unkin.net'
+  - 'ausyd1nxvm2129.main.unkin.net'
+externaldns::externaldns_key_algorithm: 'hmac-sha256'
+
+# networking
+anycast_ip: 198.18.19.20
+systemd::manage_networkd: true
+systemd::manage_all_network_files: true
+networking::interfaces:
+  eth0:
+    type: physical
+    forwarding: true
+    dhcp: true
+  anycast0:
+    type: dummy
+    ipaddress: "%{hiera('anycast_ip')}"
+    netmask: 255.255.255.255
+    mtu: 1500
+
+# frrouting
+exporters::frr_exporter::enable: true
+frrouting::ospfd_router_id: "%{facts.networking.ip}"
+frrouting::ospfd_redistribute:
+  - connected
+frrouting::ospfd_interfaces:
+  eth0:
+    area: 0.0.0.0
+  anycast0:
+    area: 0.0.0.0
+frrouting::daemons:
+  ospfd: true
+
+# consul
+profiles::consul::client::node_rules:
+  - resource: service
+    segment: frr_exporter
+    disposition: write
+
+# additional repos
+profiles::yum::global::repos:
+  frr-extras:
+    name: frr-extras
+    descr: frr-extras repository
+    target: /etc/yum.repos.d/frr-extras.repo
+    baseurl: https://packagerepo.service.consul/frr/el9/extras-daily/%{facts.os.architecture}/os
+    gpgkey: https://packagerepo.service.consul/frr/el9/extras-daily/%{facts.os.architecture}/os/RPM-GPG-KEY-FRR
+    mirrorlist: absent
+  frr-stable:
+    name: frr-stable
+    descr: frr-stable repository
+    target: /etc/yum.repos.d/frr-stable.repo
+    baseurl: https://packagerepo.service.consul/frr/el9/stable-daily/%{facts.os.architecture}/os
+    gpgkey: https://packagerepo.service.consul/frr/el9/stable-daily/%{facts.os.architecture}/os/RPM-GPG-KEY-FRR
+    mirrorlist: absent

hieradata/roles/infra/dns/resolver.yaml

@@ -82,6 +82,11 @@ profiles::dns::resolver::zones:
       - 10.10.16.32
       - 10.10.16.33
     forward: 'only'
+  k8s.syd1.au.unkin.net-forward:
+    domain: 'k8s.syd1.au.unkin.net'
+    zone_type: 'forward'
+    forwarders: "%{alias('profiles_dns_upstream_forwarder_k8s')}"
+    forward: 'only'
   unkin.net-forward:
     domain: 'unkin.net'
     zone_type: 'forward'
@@ -172,6 +177,11 @@ profiles::dns::resolver::zones:
     zone_type: 'forward'
     forwarders: "%{alias('profiles_dns_upstream_forwarder_unkin')}"
     forward: 'only'
+  200.18.198.in-addr.arpa-forward:
+    domain: '200.18.198.in-addr.arpa'
+    zone_type: 'forward'
+    forwarders: "%{alias('profiles_dns_upstream_forwarder_k8s')}"
+    forward: 'only'
   consul-forward:
     domain: 'consul'
     zone_type: 'forward'
@@ -188,6 +198,7 @@ profiles::dns::resolver::views:
       - network.unkin.net-forward
       - prod.unkin.net-forward
       - consul-forward
+      - k8s.syd1.au.unkin.net-forward
       - 13.18.198.in-addr.arpa-forward
       - 14.18.198.in-addr.arpa-forward
       - 15.18.198.in-addr.arpa-forward

modules/externaldns/manifests/init.pp

@@ -0,0 +1,15 @@
+# ExternalDNS BIND module - automatically configures master or slave
+class externaldns (
+  Stdlib::Fqdn $bind_master_hostname,
+  Array[Stdlib::Fqdn] $k8s_zones = [],
+  Array[Stdlib::Fqdn] $slave_servers = [],
+  String $externaldns_key_secret = '',
+  String $externaldns_key_algorithm = 'hmac-sha256',
+) {
+
+  if $trusted['certname'] == $bind_master_hostname {
+    include externaldns::master
+  } else {
+    include externaldns::slave
+  }
+}

modules/externaldns/manifests/master.pp

@@ -0,0 +1,45 @@
+# ExternalDNS BIND master server class
+class externaldns::master inherits externaldns {
+
+  include bind
+
+  # Query PuppetDB for slave server IP addresses
+  $slave_ips = $externaldns::slave_servers.map |$fqdn| {
+    puppetdb_query("inventory[facts.networking.ip] { certname = '${fqdn}' }")[0]['facts.networking.ip']
+  }.filter |$ip| { $ip != undef }
+
+  # Create TSIG key for ExternalDNS authentication
+  bind::key { 'externaldns-key':
+    algorithm => $externaldns::externaldns_key_algorithm,
+    secret    => $externaldns::externaldns_key_secret,
+  }
+
+  # Create ACL for slave servers
+  if !empty($slave_ips) {
+    bind::acl { 'dns-slaves':
+      addresses => $slave_ips,
+    }
+  }
+
+  # Create master zones for each Kubernetes domain
+  $externaldns::k8s_zones.each |$zone| {
+    bind::zone { $zone:
+      zone_type       => 'master',
+      dynamic         => true,
+      allow_updates   => ['key externaldns-key'],
+      allow_transfers => empty($slave_ips) ? {
+        true  => [],
+        false => ['dns-slaves'],
+      },
+      ns_notify       => !empty($slave_ips),
+      also_notify     => $slave_ips,
+      dnssec          => false,
+    }
+  }
+
+  # Create default view to include the zones
+  bind::view { 'externaldns':
+    recursion => false,
+    zones     => $externaldns::k8s_zones,
+  }
+}

modules/externaldns/manifests/slave.pp

@@ -0,0 +1,36 @@
+# ExternalDNS BIND slave server class
+class externaldns::slave inherits externaldns {
+
+  include bind
+
+  # Query PuppetDB for master server IP address
+  $query = "inventory[facts.networking.ip] { certname = '${externaldns::bind_master_hostname}' }"
+  $master_ip = puppetdb_query($query)[0]['facts.networking.ip']
+
+  # Create TSIG key for zone transfers (same as master)
+  bind::key { 'externaldns-key':
+    algorithm => $externaldns::externaldns_key_algorithm,
+    secret    => $externaldns::externaldns_key_secret,
+  }
+
+  # Create ACL for master server
+  bind::acl { 'dns-master':
+    addresses => [$master_ip],
+  }
+
+  # Create slave zones for each Kubernetes domain
+  $externaldns::k8s_zones.each |$zone| {
+    bind::zone { $zone:
+      zone_type    => 'slave',
+      masters      => [$master_ip],
+      allow_notify => ['dns-master'],
+      ns_notify    => false,
+    }
+  }
+
+  # Create default view to include the zones
+  bind::view { 'externaldns':
+    recursion => false,
+    zones     => $externaldns::k8s_zones,
+  }
+}

site/roles/manifests/infra/dns/externaldns.pp

@@ -0,0 +1,11 @@
+# BIND server role for ExternalDNS integration
+class roles::infra::dns::externaldns {
+  if $facts['firstrun'] {
+    include profiles::defaults
+    include profiles::firstrun::init
+  } else {
+    include profiles::defaults
+    include profiles::base
+    include externaldns
+  }
+}