init: go api with CI/CD

.gitea/workflows/build.yml

@@ -0,0 +1,50 @@
+name: Build & Deploy Go API
+
+on:
+  push:
+    branches: [main]
+
+env:
+  REGISTRY: zot-registry.cicd.svc.cluster.local:5000
+
+jobs:
+  build:
+    runs-on: self-hosted
+    steps:
+      - name: Install build tools
+        run: apk add --no-cache curl git docker-cli 2>/dev/null || true
+
+      - name: Clone + prepare
+        run: |
+          WORK=/root/.cache/demo-go-api
+          mkdir -p $WORK
+          cd $WORK
+          [ -d .git ] || git clone http://joe:${GITEA_TOKEN}@192.168.1.212:3000/joe/demo-go-api.git .
+          git pull
+
+      - name: Build & push image
+        run: |
+          cd /root/.cache/demo-go-api
+          SHORT=${GITHUB_SHA::8}
+          TAG="${REGISTRY}/demo-go-api:${SHORT}"
+          LATEST="${REGISTRY}/demo-go-api:latest"
+          docker build --build-arg VERSION=${SHORT} -t "${TAG}" -t "${LATEST}" .
+          docker push "${TAG}"
+          docker push "${LATEST}"
+          echo "✓ Pushed ${TAG}"
+        env:
+          GITHUB_SHA: ${{ github.sha }}
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+
+      - name: Patch ArgoCD
+        run: |
+          SHORT=${GITHUB_SHA::8}
+          if kubectl -n argocd get application demo-go-api &>/dev/null; then
+            kubectl -n argocd patch application demo-go-api --type merge \
+              -p "{\"spec\":{\"source\":{\"helm\":{\"parameters\":[{\"name\":\"image.tag\",\"value\":\"${SHORT}\"}]}}}}"
+            echo "✓ ArgoCD patched"
+          else
+            echo "⚠ demo-go-api Application not yet created"
+          fi
+        env:
+          GITHUB_SHA: ${{ github.sha }}

Dockerfile

@@ -0,0 +1,14 @@
+FROM golang:1.23-alpine AS builder
+WORKDIR /app
+COPY go.mod ./
+RUN go mod download
+COPY . .
+ARG VERSION=dev
+RUN CGO_ENABLED=0 go build -ldflags="-s -w -X main.VERSION=${VERSION}" -o /out/api .
+
+FROM gcr.io/distroless/static-debian12:nonroot
+WORKDIR /app
+COPY --from=builder /out/api /app/api
+USER nonroot:nonroot
+EXPOSE 8080
+ENTRYPOINT ["/app/api"]

deploy/helm/Chart.yaml

@@ -0,0 +1,9 @@
+# Minimal Helm chart for any service
+# Place at: <repo>/deploy/helm/
+
+apiVersion: v2
+name: demo-go-api
+description: Standard Helm chart for k3s services
+type: application
+version: 0.1.0
+appVersion: "1.0.0"

deploy/helm/templates/deployment.yaml

@@ -0,0 +1,85 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: {{ .Chart.Name }}
+  labels:
+    app: {{ .Chart.Name }}
+    app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
+spec:
+  replicas: {{ .Values.replicaCount }}
+  selector:
+    matchLabels:
+      app: {{ .Chart.Name }}
+  template:
+    metadata:
+      labels:
+        app: {{ .Chart.Name }}
+    spec:
+      containers:
+        - name: {{ .Chart.Name }}
+          image: "{{ .Values.image.registry }}/{{ .Values.image.name }}:{{ .Values.image.tag }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          ports:
+            - name: http
+              containerPort: {{ .Values.service.port }}
+              protocol: TCP
+          {{- if .Values.probes.liveness.enabled }}
+          livenessProbe:
+            httpGet:
+              path: {{ .Values.probes.liveness.path }}
+              port: {{ .Values.probes.liveness.port }}
+            initialDelaySeconds: 30
+            periodSeconds: 10
+          {{- end }}
+          {{- if .Values.probes.readiness.enabled }}
+          readinessProbe:
+            httpGet:
+              path: {{ .Values.probes.readiness.path }}
+              port: {{ .Values.probes.readiness.port }}
+            initialDelaySeconds: 5
+            periodSeconds: 5
+          {{- end }}
+          env:
+            {{- toYaml .Values.env | nindent 12 }}
+          resources:
+            {{- toYaml .Values.resources | nindent 12 }}
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ .Chart.Name }}
+spec:
+  type: {{ .Values.service.type }}
+  selector:
+    app: {{ .Chart.Name }}
+  ports:
+    - port: {{ .Values.service.port }}
+      targetPort: http
+      protocol: TCP
+      name: http
+{{- if .Values.ingress.enabled }}
+---
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: {{ .Chart.Name }}
+  annotations:
+    {{- if .Values.ingress.className }}
+    kubernetes.io/ingress.class: {{ .Values.ingress.className }}
+    {{- end }}
+spec:
+  {{- if .Values.ingress.className }}
+  ingressClassName: {{ .Values.ingress.className }}
+  {{- end }}
+  rules:
+    - host: {{ .Values.ingress.host }}
+      http:
+        paths:
+          - path: {{ .Values.ingress.path | default "/" }}
+            pathType: Prefix
+            backend:
+              service:
+                name: {{ .Chart.Name }}
+                port:
+                  number: {{ .Values.service.port }}
+{{- end }}

deploy/helm/values.yaml

@@ -0,0 +1,38 @@
+# Default values
+image:
+  registry: 127.0.0.1:5000
+  name: demo-go-api
+  tag: latest
+  pullPolicy: Always
+
+replicaCount: 2
+
+service:
+  type: ClusterIP
+  port: 8080
+
+ingress:
+  enabled: false
+  className: traefik
+  host: demo-go-api.local
+  path: /
+
+resources:
+  requests:
+    cpu: 100m
+    memory: 128Mi
+  limits:
+    cpu: 500m
+    memory: 512Mi
+
+env: []
+
+probes:
+  liveness:
+    enabled: true
+    path: /healthz
+    port: 8080
+  readiness:
+    enabled: true
+    path: /healthz
+    port: 8080

go.mod

@@ -0,0 +1,3 @@
+module github.com/joe/demo-go-api
+
+go 1.23

main.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"os"
+	"time"
+)
+
+type Response struct {
+	Service  string `json:"service"`
+	Message  string `json:"message"`
+	Time     string `json:"time"`
+	Hostname string `json:"hostname"`
+	Version  string `json:"version"`
+}
+
+func main() {
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+	}
+
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		hostname, _ := os.Hostname()
+		resp := Response{
+			Service:  "demo-go-api",
+			Message:  "Hello from Go API!",
+			Time:     time.Now().Format(time.RFC3339),
+			Hostname: hostname,
+			Version:  os.Getenv("VERSION"),
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(resp)
+	})
+
+	http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("ok"))
+	})
+
+	log.Printf("Listening on :%s", port)
+	log.Fatal(http.ListenAndServe(":"+port, nil))
+}