From e6ad9b5077c3a6357ff8aa95dc5911cb813f6fa8 Mon Sep 17 00:00:00 2001
From: Slawomir Koszewski <slawek@koszewscy.waw.pl>
Date: Sat, 25 Jul 2026 22:49:46 +0200
Subject: [PATCH] feat: add k3s deployment and service configurations for
 ok-server

---
 README.md                 | 44 +++++++++++++++++++++++++++++++++++++++
 k3s/deployment.yaml       | 20 ++++++++++++++++++
 k3s/expose-ingress.yaml   | 26 +++++++++++++++++++++++
 k3s/expose-servicelb.yaml | 11 ++++++++++
 4 files changed, 101 insertions(+)
 create mode 100644 k3s/deployment.yaml
 create mode 100644 k3s/expose-ingress.yaml
 create mode 100644 k3s/expose-servicelb.yaml

diff --git a/README.md b/README.md
index 931e9be..2fda80b 100644
--- a/README.md
+++ b/README.md
@@ -96,6 +96,50 @@ container run --rm -d --name ok-server -c 1 -m 256m -p 8080:8080 ok-server
 
 This will start the server and expose it on port 8080. The container will run until stopped, and will be removed when stopped. You can stop it with `container stop ok-server`.
 
+### nerdctl with BuildKit on a k3s server
+
+Build the image directly into the containerd instance used by k3s:
+
+```bash
+sudo nerdctl build -t ok-server .
+sudo nerdctl images
+```
+
+On a single-node k3s cluster the image is now available to the kubelet without a
+registry. The [k3s/deployment.yaml](k3s/deployment.yaml) Deployment references
+it with `imagePullPolicy: Never`:
+
+```bash
+kubectl apply -f k3s/deployment.yaml
+```
+
+Expose the app with one of the two options below.
+
+#### Option 1: Traefik Ingress
+
+k3s includes the Traefik ingress controller. The ClusterIP Service and Ingress
+in [k3s/expose-ingress.yaml](k3s/expose-ingress.yaml) expose the app on port 80
+of the node's IP address:
+
+```bash
+kubectl apply -f k3s/expose-ingress.yaml
+curl -si "http://<node-ip>/"
+```
+
+#### Option 2: ServiceLB
+
+k3s also includes the ServiceLB load balancer. The single `LoadBalancer`
+Service in [k3s/expose-servicelb.yaml](k3s/expose-servicelb.yaml) exposes the
+app on port 8080 of the node's IP address, without an Ingress:
+
+```bash
+kubectl apply -f k3s/expose-servicelb.yaml
+curl -si "http://<node-ip>:8080"
+```
+
+On a multi-node cluster, push the image to a registry instead, so every node can
+pull it.
+
 ## License
 
 This project is licensed under the MIT License. See the [LICENSE](LICENSE) file for details.
diff --git a/k3s/deployment.yaml b/k3s/deployment.yaml
new file mode 100644
index 0000000..7b44c47
--- /dev/null
+++ b/k3s/deployment.yaml
@@ -0,0 +1,20 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: ok-server
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: ok-server
+  template:
+    metadata:
+      labels:
+        app: ok-server
+    spec:
+      containers:
+        - name: ok-server
+          image: ok-server
+          imagePullPolicy: Never
+          ports:
+            - containerPort: 8080
diff --git a/k3s/expose-ingress.yaml b/k3s/expose-ingress.yaml
new file mode 100644
index 0000000..fb3c3cc
--- /dev/null
+++ b/k3s/expose-ingress.yaml
@@ -0,0 +1,26 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: ok-server
+spec:
+  selector:
+    app: ok-server
+  ports:
+    - port: 8080
+      targetPort: 8080
+---
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: ok-server
+spec:
+  rules:
+    - http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: ok-server
+                port:
+                  number: 8080
diff --git a/k3s/expose-servicelb.yaml b/k3s/expose-servicelb.yaml
new file mode 100644
index 0000000..b745e81
--- /dev/null
+++ b/k3s/expose-servicelb.yaml
@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: ok-server
+spec:
+  type: LoadBalancer
+  selector:
+    app: ok-server
+  ports:
+    - port: 8080
+      targetPort: 8080