feat(open-webui): deploy Open WebUI with litellm backend

Deploys Open WebUI (chat.k8s.syd1.au.unkin.net) into the open-webui
namespace via the aitooling ArgoCD project. Uses SQLite with a 10Gi
cephrbd PVC for persistence, routes model requests to the existing
litellm deployment, and exposes the UI through the traefik-external
gateway. Credentials (OPENAI_API_KEY, WEBUI_SECRET_KEY) are injected
via VaultStaticSecret from kv/kubernetes/namespace/open-webui/default.

Closes #155

apps/base/open-webui/deployment.yaml

@@ -0,0 +1,69 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: open-webui
+  namespace: open-webui
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: open-webui
+  strategy:
+    type: Recreate
+  template:
+    metadata:
+      annotations:
+        reloader.stakater.com/auto: "true"
+      labels:
+        app: open-webui
+    spec:
+      containers:
+        - name: open-webui
+          image: ghcr.io/open-webui/open-webui:main
+          imagePullPolicy: Always
+          ports:
+            - containerPort: 8080
+              name: http
+              protocol: TCP
+          env:
+            - name: OPENAI_API_BASE_URL
+              value: http://litellm-pooler.litellm.svc.cluster.local:4000
+            - name: WEBUI_URL
+              value: https://chat.k8s.syd1.au.unkin.net
+          envFrom:
+            - secretRef:
+                name: open-webui-credentials
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: 8080
+            failureThreshold: 3
+            initialDelaySeconds: 30
+            periodSeconds: 30
+            successThreshold: 1
+            timeoutSeconds: 5
+          readinessProbe:
+            httpGet:
+              path: /health
+              port: 8080
+            failureThreshold: 3
+            initialDelaySeconds: 10
+            periodSeconds: 10
+            successThreshold: 1
+            timeoutSeconds: 5
+          resources:
+            limits:
+              cpu: "2"
+              memory: 4Gi
+            requests:
+              cpu: 250m
+              memory: 512Mi
+          volumeMounts:
+            - mountPath: /app/backend/data
+              name: data
+      restartPolicy: Always
+      volumes:
+        - name: data
+          persistentVolumeClaim:
+            claimName: open-webui-data

apps/base/open-webui/gateway.yaml

@@ -0,0 +1,37 @@
+---
+apiVersion: gateway.networking.k8s.io/v1
+kind: Gateway
+metadata:
+  labels:
+    traefik.io/instance: external
+  annotations:
+    cert-manager.io/cluster-issuer: vault-issuer
+    cert-manager.io/common-name: chat.k8s.syd1.au.unkin.net
+    cert-manager.io/private-key-size: "4096"
+    external-dns.alpha.kubernetes.io/hostname: chat.k8s.syd1.au.unkin.net
+    external-dns.alpha.kubernetes.io/target: 198.18.200.0
+  name: open-webui
+  namespace: open-webui
+spec:
+  gatewayClassName: traefik-external
+  listeners:
+    - allowedRoutes:
+        namespaces:
+          from: Same
+      hostname: chat.k8s.syd1.au.unkin.net
+      name: http
+      port: 80
+      protocol: HTTP
+    - allowedRoutes:
+        namespaces:
+          from: Same
+      hostname: chat.k8s.syd1.au.unkin.net
+      name: https
+      port: 443
+      protocol: HTTPS
+      tls:
+        certificateRefs:
+          - group: ""
+            kind: Secret
+            name: open-webui-tls
+        mode: Terminate

apps/base/open-webui/httproute.yaml

@@ -0,0 +1,49 @@
+---
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: open-webui-http-redirect
+  namespace: open-webui
+spec:
+  hostnames:
+    - chat.k8s.syd1.au.unkin.net
+  parentRefs:
+    - group: gateway.networking.k8s.io
+      kind: Gateway
+      name: open-webui
+      sectionName: http
+  rules:
+    - filters:
+        - type: RequestRedirect
+          requestRedirect:
+            scheme: https
+            statusCode: 301
+      matches:
+        - path:
+            type: PathPrefix
+            value: /
+---
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: open-webui
+  namespace: open-webui
+spec:
+  hostnames:
+    - chat.k8s.syd1.au.unkin.net
+  parentRefs:
+    - group: gateway.networking.k8s.io
+      kind: Gateway
+      name: open-webui
+      sectionName: https
+  rules:
+    - backendRefs:
+        - group: ""
+          kind: Service
+          name: open-webui
+          port: 8080
+          weight: 1
+      matches:
+        - path:
+            type: PathPrefix
+            value: /

apps/base/open-webui/kustomization.yaml

@@ -0,0 +1,13 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  - namespace.yaml
+  - pvc.yaml
+  - deployment.yaml
+  - service.yaml
+  - gateway.yaml
+  - httproute.yaml
+  - vaultauth.yaml
+  - vaultstaticsecret.yaml

apps/base/open-webui/namespace.yaml

@@ -0,0 +1,5 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: open-webui

apps/base/open-webui/pvc.yaml

@@ -0,0 +1,13 @@
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: open-webui-data
+  namespace: open-webui
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 10Gi
+  storageClassName: cephrbd-fast-delete

apps/base/open-webui/service.yaml

@@ -0,0 +1,17 @@
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: open-webui
+  namespace: open-webui
+spec:
+  internalTrafficPolicy: Cluster
+  ports:
+    - name: http
+      port: 8080
+      protocol: TCP
+      targetPort: http
+  selector:
+    app: open-webui
+  sessionAffinity: None
+  type: ClusterIP

apps/base/open-webui/vaultauth.yaml

@@ -0,0 +1,18 @@
+---
+apiVersion: secrets.hashicorp.com/v1beta1
+kind: VaultAuth
+metadata:
+  name: default
+  namespace: open-webui
+spec:
+  allowedNamespaces:
+    - open-webui
+  kubernetes:
+    audiences:
+      - vault
+    role: default
+    serviceAccount: default
+    tokenExpirationSeconds: 600
+  method: kubernetes
+  mount: k8s/au/syd1
+  vaultConnectionRef: vso-system/default

apps/base/open-webui/vaultstaticsecret.yaml

@@ -0,0 +1,17 @@
+---
+apiVersion: secrets.hashicorp.com/v1beta1
+kind: VaultStaticSecret
+metadata:
+  name: open-webui-credentials
+  namespace: open-webui
+spec:
+  destination:
+    create: true
+    name: open-webui-credentials
+    overwrite: true
+  hmacSecretData: true
+  mount: kv
+  path: kubernetes/namespace/open-webui/default/open-webui-credentials
+  refreshAfter: 5m
+  type: kv-v2
+  vaultAuthRef: default

apps/overlays/au-syd1/open-webui/kustomization.yaml

@@ -0,0 +1,6 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  - ../../../base/open-webui

argocd/applicationsets/aitooling.yaml

@@ -11,6 +11,7 @@ spec:
       revision: HEAD
       directories:
       - path: apps/overlays/*/litellm
+      - path: apps/overlays/*/open-webui
       - path: apps/overlays/*/paperclip
   template:
     metadata:

argocd/projects/aitooling.yaml

@@ -11,6 +11,8 @@ spec:
   destinations:
     - namespace: 'litellm'
       server: https://kubernetes.default.svc
+    - namespace: 'open-webui'
+      server: https://kubernetes.default.svc
     - namespace: 'paperclip'
       server: https://kubernetes.default.svc
   clusterResourceWhitelist: