feat(apps): Add openvpn

2026-10-10 00:42:58 +05:30
parent 02cba0952e
commit e98a0e0b17
15 changed files with 449 additions and 0 deletions
@@ -0,0 +1,97 @@
+apiVersion: v1
+data:
+  client.conf.tpl: |
+    client
+    dev tun
+    {{- range $server := .Hosts }}
+    remote {{ $server.Host }} {{ $server.Port }} {{ $server.Protocol }}
+    {{- end }}
+    nobind
+    persist-key
+    persist-tun
+    remote-cert-tls server
+    tls-version-min 1.2
+    verb 3
+
+    <ca>
+    {{ .CA -}}
+    </ca>
+    <cert>
+    {{ .Cert -}}
+    </cert>
+    <key>
+    {{ .Key -}}
+    </key>
+    <tls-crypt>
+    {{ .TLS -}}
+    </tls-crypt>
+  entrypoint.sh: |
+    #!/bin/sh
+    set -eu
+
+    # These rules live in the pod's network namespace, not the node's. VPN clients
+    # may reach the home LAN, but not this pod (ovpn-admin has no auth of its own),
+    # the pod network or the service network.
+    iptables -F INPUT
+    iptables -F FORWARD
+    iptables -t nat -F POSTROUTING
+    iptables -A INPUT -i tun0 -j DROP
+    iptables -A FORWARD -i tun0 -d "$CLUSTER_CIDR" -j DROP
+    iptables -A FORWARD -i tun0 -d "$SERVICE_CIDR" -j DROP
+    iptables -t nat -A POSTROUTING -s "$VPN_NETWORK" -o eth0 -j MASQUERADE
+
+    if [ "$(cat /proc/sys/net/ipv4/ip_forward)" != 1 ]; then
+      echo "net.ipv4.ip_forward is disabled in the pod network namespace" >&2
+      exit 1
+    fi
+
+    mkdir -p /dev/net
+    [ -c /dev/net/tun ] || mknod /dev/net/tun c 10 200
+
+    for f in ca.crt issued/server.crt private/server.key ta.key crl.pem; do
+      until [ -f "/etc/openvpn/certs/pki/$f" ]; do
+        echo "waiting for $f from ovpn-admin"
+        sleep 2
+      done
+    done
+
+    exec openvpn --config /etc/openvpn/openvpn.conf
+  openvpn.conf: |
+    # After editing this ConfigMap, bump openvpn.whyredfire.dev/config-revision
+    # on the Deployment to restart it.
+    port 1194
+    proto udp
+    dev tun0
+    topology subnet
+    server 10.8.0.0 255.255.255.0
+    client-config-dir /etc/openvpn/ccd
+    management 127.0.0.1 8989
+
+    # Written by ovpn-admin from the PKI it keeps in Kubernetes Secrets.
+    ca /etc/openvpn/certs/pki/ca.crt
+    cert /etc/openvpn/certs/pki/issued/server.crt
+    key /etc/openvpn/certs/pki/private/server.key
+    crl-verify /etc/openvpn/certs/pki/crl.pem
+    tls-crypt /etc/openvpn/certs/pki/ta.key
+    dh none
+    tls-version-min 1.2
+    remote-cert-tls client
+
+    # Split tunnel: only the home LAN goes through the VPN.
+    push "route 192.168.2.0 255.255.255.0"
+    push "dhcp-option DNS 192.168.2.1"
+
+    # DCO would need the ovpn kernel module on the node; plain tun keeps the pod self-contained.
+    disable-dco
+    keepalive 10 60
+    persist-key
+    persist-tun
+    explicit-exit-notify 1
+    user nobody
+    group nogroup
+    status /tmp/openvpn-status.log
+    verb 3
+kind: ConfigMap
+metadata:
+  name: openvpn
+  namespace: openvpn
@@ -0,0 +1,138 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: openvpn
+  namespace: openvpn
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: openvpn
+  strategy:
+    type: Recreate
+  template:
+    metadata:
+      annotations:
+        openvpn.whyredfire.dev/config-revision: "1"
+      labels:
+        app.kubernetes.io/name: openvpn
+    spec:
+      containers:
+        - args:
+            - |
+              # The sync API serves the PKI to replica servers, which this
+              # setup doesn't use, so lock it with a throwaway token.
+              exec /app/ovpn-admin \
+                --storage.backend=kubernetes.secrets \
+                --listen.port=8080 \
+                --mgmt=main=127.0.0.1:8989 \
+                --ccd \
+                --ccd.path=/mnt/ccd \
+                --easyrsa.path=/mnt/certs \
+                --ovpn.network=10.8.0.0/24 \
+                --ovpn.server=openvpn.whyredfire.dev:27299:udp \
+                --templates.clientconfig-path=/templates/client.conf.tpl \
+                --master.sync-token="$(head -c 32 /dev/urandom | od -An -tx1 | tr -d ' \n')"
+          command:
+            - /bin/sh
+            - -c
+          image: ghcr.io/palark/ovpn-admin/ovpn-admin:master@sha256:8487aec078954ba682fb22cd2882ec3e4faaa03a47cc3e06f786b3ec493ded79
+          name: ovpn-admin
+          ports:
+            - containerPort: 8080
+              name: http
+          readinessProbe:
+            httpGet:
+              path: /ping
+              port: http
+          resources:
+            limits:
+              cpu: 500m
+              memory: 128Mi
+            requests:
+              cpu: 10m
+              memory: 32Mi
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              drop:
+                - ALL
+          volumeMounts:
+            - mountPath: /mnt/certs
+              name: certs
+            - mountPath: /mnt/ccd
+              name: ccd
+            - mountPath: /templates/client.conf.tpl
+              name: config
+              readOnly: true
+              subPath: client.conf.tpl
+        - command:
+            - /entrypoint.sh
+          env:
+            - name: CLUSTER_CIDR
+              value: 10.42.0.0/16
+            - name: SERVICE_CIDR
+              value: 10.43.0.0/16
+            - name: VPN_NETWORK
+              value: 10.8.0.0/24
+          image: ghcr.io/palark/ovpn-admin/openvpn:master@sha256:130657e1938675f9492dcb554fdf63357eaddad90a1514c73db9a433e3de77b6
+          name: openvpn
+          ports:
+            - containerPort: 1194
+              name: openvpn
+              protocol: UDP
+          resources:
+            limits:
+              cpu: "1"
+              memory: 128Mi
+            requests:
+              cpu: 10m
+              memory: 32Mi
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              add:
+                - MKNOD
+                - NET_ADMIN
+                - NET_RAW
+                - SETGID
+                - SETUID
+              drop:
+                - ALL
+          volumeMounts:
+            - mountPath: /dev/net
+              name: dev-net
+            - mountPath: /etc/openvpn/certs
+              name: certs
+              readOnly: true
+            - mountPath: /etc/openvpn/ccd
+              name: ccd
+              readOnly: true
+            - mountPath: /etc/openvpn/openvpn.conf
+              name: config
+              readOnly: true
+              subPath: openvpn.conf
+            - mountPath: /entrypoint.sh
+              name: entrypoint
+              readOnly: true
+              subPath: entrypoint.sh
+      dnsConfig:
+        nameservers:
+          - 192.168.2.1
+      dnsPolicy: None
+      serviceAccountName: openvpn
+      volumes:
+        - emptyDir:
+            medium: Memory
+          name: certs
+        - emptyDir: {}
+          name: ccd
+        - emptyDir: {}
+          name: dev-net
+        - configMap:
+            name: openvpn
+          name: config
+        - configMap:
+            defaultMode: 493
+            name: openvpn
+          name: entrypoint
@@ -0,0 +1,37 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  annotations:
+    argocd.argoproj.io/sync-wave: "2"
+  name: openvpn-admin
+  namespace: openvpn
+spec:
+  hostnames:
+    - openvpn-admin.whyredfire.dev
+  parentRefs:
+    - kind: Gateway
+      name: traefik-gateway
+      namespace: traefik
+      sectionName: websecure
+  rules:
+    - backendRefs:
+        - name: authentik-server
+          namespace: authentik
+          port: 80
+      matches:
+        - path:
+            type: PathPrefix
+            value: /outpost.goauthentik.io
+    - backendRefs:
+        - name: openvpn-admin
+          port: 8080
+      filters:
+        - extensionRef:
+            group: traefik.io
+            kind: Middleware
+            name: authentik
+          type: ExtensionRef
+      matches:
+        - path:
+            type: PathPrefix
+            value: /
@@ -0,0 +1,13 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - serviceaccount.yaml
+  - role.yaml
+  - rolebinding.yaml
+  - configmap.yaml
+  - deployment.yaml
+  - service.yaml
+  - service-admin.yaml
+  - networkpolicy.yaml
+  - middleware.yaml
+  - httproute.yaml
@@ -0,0 +1,17 @@
+apiVersion: traefik.io/v1alpha1
+kind: Middleware
+metadata:
+  annotations:
+    argocd.argoproj.io/sync-wave: "1"
+  name: authentik
+  namespace: openvpn
+spec:
+  forwardAuth:
+    address: http://authentik-server.authentik.svc.cluster.local/outpost.goauthentik.io/auth/traefik
+    authResponseHeaders:
+      - X-authentik-username
+      - X-authentik-groups
+      - X-authentik-email
+      - X-authentik-name
+      - X-authentik-uid
+    trustForwardHeader: true
@@ -0,0 +1,22 @@
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: openvpn
+  namespace: openvpn
+spec:
+  ingress:
+    - ports:
+        - port: 1194
+          protocol: UDP
+    - from:
+        - namespaceSelector:
+            matchLabels:
+              kubernetes.io/metadata.name: traefik
+      ports:
+        - port: 8080
+          protocol: TCP
+  podSelector:
+    matchLabels:
+      app.kubernetes.io/name: openvpn
+  policyTypes:
+    - Ingress
@@ -0,0 +1,15 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: openvpn
+  namespace: openvpn
+rules:
+  - apiGroups:
+      - ""
+    resources:
+      - secrets
+    verbs:
+      - create
+      - get
+      - list
+      - update
@@ -0,0 +1,13 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: openvpn
+  namespace: openvpn
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: openvpn
+subjects:
+  - kind: ServiceAccount
+    name: openvpn
+    namespace: openvpn
@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: openvpn-admin
+  namespace: openvpn
+spec:
+  ports:
+    - name: http
+      port: 8080
+      targetPort: http
+  selector:
+    app.kubernetes.io/name: openvpn
@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: openvpn
+  namespace: openvpn
+spec:
+  externalIPs:
+    - 192.168.2.5
+  ports:
+    - name: openvpn
+      port: 51820
+      protocol: UDP
+      targetPort: openvpn
+  selector:
+    app.kubernetes.io/name: openvpn
@@ -0,0 +1,5 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: openvpn
+  namespace: openvpn