finish the main code

app/__init__.py

@@ -0,0 +1,13 @@
+"""
+app/__init__.py
+
+Makes `app/` a Python package and exposes a single shared Config instance.
+
+Usage anywhere in the project:
+    from app import cfg
+    print(cfg.cache_ttl)
+"""
+
+from app.config import load
+
+cfg = load()

app/config.py

@@ -0,0 +1,40 @@
+"""
+app/config.py
+
+Central place for all runtime configuration.
+Values are read from environment variables, with sensible defaults.
+Nothing in this file imports from the rest of the project.
+"""
+
+import os
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class Config:
+    # Kubernetes connection
+    in_cluster: bool  # True when running as a pod inside k3s
+    kubeconfig: str  # path to kubeconfig file (ignored if in_cluster=True)
+
+    # Dashboard behaviour
+    cache_ttl: int  # seconds between Kubernetes API refreshes
+    page_title: str
+    page_icon: str
+
+    # Metrics
+    metrics_enabled: bool  # set False if metrics-server is not installed
+
+
+def load() -> Config:
+    """
+    Read config from the environment.
+    Call once at app startup — the result is immutable.
+    """
+    return Config(
+        in_cluster=os.getenv("IN_CLUSTER", "").lower() in ("1", "true", "yes"),
+        kubeconfig=os.getenv("KUBECONFIG", os.path.expanduser("~/.kube/config")),
+        cache_ttl=int(os.getenv("CACHE_TTL", "15")),
+        page_title=os.getenv("PAGE_TITLE", "k3s Dashboard"),
+        page_icon=os.getenv("PAGE_ICON", "☸️"),
+        metrics_enabled=os.getenv("METRICS_ENABLED", "true").lower() != "false",
+    )

app/k8s_client.py

@@ -0,0 +1,15 @@
+import os
+import kubernetes import client, config
+
+def get_core_client() -> client.CoreV1Api:
+    if os.getenv("IN_CLUSTER"):
+        config.load_incluster_config()
+    else:
+        config.load_kube_config(         # runs locally
+            config_file=os.getenv("KUBECONFIG", "~/.kube/config")
+        )
+    return client.CoreV1Api()
+
+def get_custom_client() -> client.CustomObjectsApi:
+    return client.CustomObjectsApi()
+

app/main.py

@@ -0,0 +1,22 @@
+from fastapi import FastAPI
+from fastapi.staticfiles import StaticFiles
+from fastapi.responses import FileResponse
+from app.routers import nodes, pods, metrics
+
+app = FastAPI(title="k3s Health Dashboard")
+
+app.include_router(nodes.router)
+app.include_router(pods.router)
+app.include_router(metrics.router)
+
+app.mount("/static", StaticFiles(directory="dashboard/static"), name="static")
+
+
+@app.get("/")
+def serve_ui():
+    return FileResponse("dashboard/index.html")
+
+
+@app.get("/health")
+def health():
+    return {"status": "ok"}

app/routers/metrics.py

@@ -0,0 +1,23 @@
+from fastapi import APIRouter
+from k8s_client import get_custom_client
+
+router = APIRouter(prefix="/metrics", tags=["metrics"])
+
+
+@router.get("/nodes")
+def node_metrics():
+    api = get_custom_client()
+    try:
+        data = api.list_cluster_custom_object(
+            group="metrics.k8s.io", version="v1beta1", plural="nodes"
+        )
+        return [
+            {
+                "name": item["metadata"]["name"],
+                "cpu_usage": item["usage"]["cpu"],  # e.g. "250m"
+                "memory_usage": item["usage"]["memory"],  # e.g. "512Mi"
+            }
+            for item in data["items"]
+        ]
+    except Exception as e:
+        return {"error": str(e), "hint": "Is metrics-server installed?"}

app/routers/nodes.py

@@ -0,0 +1,31 @@
+from fastapi import APIRouter
+from app.k8s_client import get_core_client
+
+router = APIRouter(prefix="/nodes", tags=["nodes"])
+
+
+@router.get("/")
+def list_node():
+    v1 = get_core_client()
+    nodes = v1.list_node().items
+    result = []
+    for n in nodes:
+        conditions = {c.type: c.status for c in n.status.conditions}
+        result.append(
+            {
+                "name": n.metadata.name,
+                "ready": conditions.get("Ready") == "True",
+                "cpu_capacity": n.status.capacity.get("cpu"),
+                "memory_capacity": n.status.capacity.get("memory"),
+                "labels": n.metadata.labels,
+                "age_days": _age(n.metadata.creation_timestamp),
+            }
+        )
+    return result
+
+
+def _age(ts) -> int:
+    from datetime import datetime, timezone
+
+    now = datetime.now(timezone.utc)
+    return (now - ts).days

app/routers/pods.py

@@ -0,0 +1,31 @@
+from fastapi import APIRouter, Query
+from k8s_client import get_core_client
+
+router  = APIRouter(prefix="/pods", tags=["pods"])
+
+@router.get("/")
+def list_pods(namespace: str = Query("default")):
+    v1 = get_core_client()
+    pods = v1.list_namespaced_pod(namespace=namespace).items
+    return [
+        {
+            "name": p.metadata.name,
+            "namespace": p.metadata.namespace,
+            "phase": p.status.phase,           # Pending/Running/Succeeded/Failed
+            "ready": _is_ready(p),
+            "restarts": _restarts(p),
+            "node": p.spec.node_name,
+        }
+        for p in pods
+    ]
+
+
+def _is_ready(pod) -> bool :
+    if not pod.status.conditions:
+        return False
+    for any(c.type == "Ready" and c.status == "True" for c in pod.status.conditions)
+
+def _restarts(pod) -> int:
+    if not pod.status.container_statuses:
+        return 0
+    return sum(c.restart_count for c in pod.status.container_statuses)

k3s-dashboard.yaml

@@ -0,0 +1,54 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: dashboard-sa
+  namespace: default
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: dashboard-reader
+rules:
+  - apiGroups: [""]
+    resources: ["nodes", "pods", "namespaces", "events"]
+    verbs: ["get", "list", "watch"]
+  - apiGroups: ["metrics.k8s.io"]
+    resources: ["nodes", "pods"]
+    verbs: ["get", "list"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: dashboard-reader-binding
+subjects:
+  - kind: ServiceAccount
+    name: dashboard-sa
+    namespace: default
+roleRef:
+  kind: ClusterRole
+  name: dashboard-reader
+  apiGroup: rbac.authorization.k8s.io
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: k3s-dashboard
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: k3s-dashboard
+  template:
+    metadata:
+      labels:
+        app: k3s-dashboard
+    spec:
+      serviceAccountName: dashboard-sa
+      containers:
+        - name: dashboard
+          image: your-registry/k3s-dashboard:latest
+          env:
+            - name: IN_CLUSTER
+              value: "true"
+          ports:
+            - containerPort: 8080

requirements.txt

@@ -0,0 +1,5 @@
+fastapi
+uvicorn
+kubernetes
+python-dotenv
+httpx