feat: configure K3s DNS resolver and update firewall rules for new subnet

ansible/group_vars/all/k3s.yaml

@@ -0,0 +1,10 @@
+---
+# Vars for: K3s cluster-wide DNS resolver
+# Applied by: ansible/roles/k3s-server, ansible/roles/k3s-agent
+# Description: Single source of truth for the resolver IP written into
+#   /etc/rancher/k3s/resolv.conf on every K3s node, so CoreDNS's
+#   "forward . /etc/resolv.conf" always reaches Technitium regardless of
+#   which node CoreDNS is scheduled on, or that node's own (possibly stale)
+#   host resolvers.
+
+k3s_dns_resolver: 10.10.40.53

ansible/host_vars/gpu-node.yaml

@@ -27,8 +27,8 @@ ufw_allowed_ports:
   # agent's outbound connection to the k3s server on 6443, not a direct
   # inbound connection).
   - { port: "6443",  proto: tcp, comment: "K3s API server" }
-  - { port: "10250", proto: tcp, comment: "Kubelet" }
-  - { port: "8472",  proto: udp, comment: "Flannel VXLAN" }
+  - { port: "10250", proto: tcp, comment: "Kubelet", src: "10.10.40.0/24" }
+  - { port: "8472",  proto: udp, comment: "Flannel VXLAN", src: "10.10.40.0/24" }
 
 data_dirs:
   - /data/tts-gateway

ansible/roles/common/defaults/main.yaml

@@ -23,8 +23,8 @@ ufw_allowed_ports:
   - { port: 80, proto: tcp, comment: HTTP }
   - { port: 443, proto: tcp, comment: HTTPS }
   - { port: 6443, proto: tcp, comment: K3s API server }
-  - { port: 10250, proto: tcp, comment: Kubelet }
-  - { port: 8472, proto: udp, comment: Flannel VXLAN }
+  - { port: 10250, proto: tcp, comment: Kubelet, src: 10.10.40.0/24 }
+  - { port: 8472, proto: udp, comment: Flannel VXLAN, src: 10.10.40.0/24 }
 
 data_dirs:
   - /data/gitea

ansible/roles/common/tasks/main.yaml

@@ -60,6 +60,7 @@
     rule: allow
     port: "{{ item.port }}"
     proto: "{{ item.proto }}"
+    src: "{{ item.src | default('any') }}"
     comment: "{{ item.comment }}"
   loop: "{{ ufw_allowed_ports }}"
 

ansible/roles/k3s-agent/defaults/main.yaml

@@ -6,3 +6,6 @@
 k3s_version: v1.32.4+k3s1
 k3s_server_url: https://10.10.40.53:6443
 k3s_node_token: ""
+
+k3s_agent_config:
+  resolv-conf: /etc/rancher/k3s/resolv.conf

ansible/roles/k3s-agent/handlers/main.yaml

@@ -0,0 +1,9 @@
+---
+# Part of role: k3s-agent
+# Called by: ansible/roles/k3s-agent/tasks/main.yaml
+# Description: Restarts the K3s agent when its config.yaml or resolv.conf changes.
+
+- name: Restart k3s-agent
+  ansible.builtin.service:
+    name: k3s-agent
+    state: restarted

ansible/roles/k3s-agent/tasks/main.yaml

@@ -2,7 +2,29 @@
 # Part of role: k3s-agent
 # Called by: ansible/playbooks/join-debian-agent.yaml
 #            ansible/playbooks/setup-gpu-node.yaml
-# Description: Installs K3s in agent mode, joins the cluster, labels and taints the node.
+# Description: Configures the K3s agent's DNS resolver, installs K3s in agent mode, joins the cluster, labels and taints the node.
+
+- name: Create K3s config directory
+  ansible.builtin.file:
+    path: /etc/rancher/k3s
+    state: directory
+    mode: "0755"
+
+- name: Write K3s agent config
+  ansible.builtin.copy:
+    dest: /etc/rancher/k3s/config.yaml
+    content: "{{ k3s_agent_config | to_nice_yaml }}"
+    mode: "0644"
+  notify: Restart k3s-agent
+
+- name: Write K3s DNS resolver file
+  ansible.builtin.copy:
+    dest: /etc/rancher/k3s/resolv.conf
+    content: "nameserver {{ k3s_dns_resolver }}\n"
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Restart k3s-agent
 
 - name: Download and install K3s agent
   ansible.builtin.shell:

ansible/roles/k3s-server/defaults/main.yaml

@@ -11,6 +11,7 @@ k3s_server_config:
     - traefik
   flannel-backend: vxlan
   node-ip: "{{ k3s_server_ip }}"
+  resolv-conf: /etc/rancher/k3s/resolv.conf
   tls-san:
     - "{{ k3s_server_ip }}"
     - minisforum

ansible/roles/k3s-server/handlers/main.yaml

@@ -0,0 +1,9 @@
+---
+# Part of role: k3s-server
+# Called by: ansible/roles/k3s-server/tasks/main.yaml
+# Description: Restarts K3s when its config.yaml or resolv.conf changes.
+
+- name: Restart k3s
+  ansible.builtin.service:
+    name: k3s
+    state: restarted

ansible/roles/k3s-server/tasks/main.yaml

@@ -1,7 +1,7 @@
 ---
 # Part of role: k3s-server
 # Called by: ansible/playbooks/setup-k3s.yaml
-# Description: Installs K3s server, fetches kubeconfig, installs Helm, and labels the node as primary.
+# Description: Installs K3s server, configures its DNS resolver, fetches kubeconfig, installs Helm, and labels the node as primary.
 
 - name: Create K3s config directory
   ansible.builtin.file:
@@ -14,6 +14,16 @@
     dest: /etc/rancher/k3s/config.yaml
     content: "{{ k3s_server_config | to_nice_yaml }}"
     mode: "0644"
+  notify: Restart k3s
+
+- name: Write K3s DNS resolver file
+  ansible.builtin.copy:
+    dest: /etc/rancher/k3s/resolv.conf
+    content: "nameserver {{ k3s_dns_resolver }}\n"
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Restart k3s
 
 - name: Download and install K3s
   ansible.builtin.shell:

manifests/media/gluetun-proxy.yaml

@@ -49,7 +49,7 @@ spec:
             - name: HTTPPROXY_LOG
               value: "off"
             - name: FIREWALL_OUTBOUND_SUBNETS
-              value: "10.42.0.0/16,10.43.0.0/16,192.168.7.0/24"
+              value: "10.42.0.0/16,10.43.0.0/16,10.10.40.0/24"
             - name: BLOCK_IPV6
               value: "on"
           ports:

manifests/media/jdownloader.yaml

@@ -46,7 +46,7 @@ spec:
                   name: pia-credentials
                   key: OPENVPN_PASSWORD
             - name: FIREWALL_OUTBOUND_SUBNETS
-              value: "10.42.0.0/16,10.43.0.0/16,192.168.7.0/24"
+              value: "10.42.0.0/16,10.43.0.0/16,10.10.40.0/24"
             - name: BLOCK_IPV6
               value: "on"
           startupProbe:

manifests/media/qbittorrent.yaml

@@ -65,7 +65,7 @@ spec:
                   name: pia-credentials
                   key: OPENVPN_PASSWORD
             - name: FIREWALL_OUTBOUND_SUBNETS
-              value: "10.42.0.0/16,10.43.0.0/16,192.168.7.0/24"
+              value: "10.42.0.0/16,10.43.0.0/16,10.10.40.0/24"
             - name: BLOCK_IPV6
               value: "on"
           startupProbe: