Scaffold DaemonSet, use distroless image

Makefile

@@ -37,9 +37,17 @@ lint:
 test-unit:
 	@cd app && go test ./... -cover;
 
+.PHONY: preview
+preview:
+	@helm template ./helm/pi-agent
+
 .PHONY: deploy
 deploy:
 	@source venv/activate > /dev/null; \
 	git fetch origin main --quiet; \
+	IMAGE_TAG=$$(git rev-parse --short origin/main); \
+	echo "Deploying image tag: $$IMAGE_TAG"; \
 	helm upgrade --install pi-agent helm/pi-agent \
-        --set image.tag=$(shell git rev-parse --short origin/main);
+        --set image.tag=$$IMAGE_TAG \
+		--namespace=pi-agent \
+        --create-namespace; 

docker/Dockerfile

@@ -4,6 +4,6 @@ WORKDIR /app
 COPY . .
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=${TARGETARCH} go build -o pi-agent .
 
-FROM alpine:3.21
+FROM scratch
 COPY --from=builder /app/pi-agent /pi-agent
 ENTRYPOINT ["/pi-agent"]

helm/pi-agent/Chart.yaml

@@ -1,6 +1,6 @@
 apiVersion: v2
 name: pi-agent
-description: A Helm chart for Kubernetes
+description: Collects basic Raspberry Pi metrics
 
 # A chart can be either an 'application' or a 'library' chart.
 #
@@ -21,4 +21,4 @@ version: 0.1.0
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
 # It is recommended to use it with quotes.
-appVersion: "1.16.0"
+appVersion: "1.0.0"

helm/pi-agent/templates/_helpers.tpl

@@ -0,0 +1,13 @@
+# templates/_helpers.tpl
+
+# Standard labels applied to all resources
+{{- define "pi-agent.labels" -}}
+helm.sh/chart: {{ .Chart.Name }}-{{ .Chart.Version }}
+app.kubernetes.io/name: {{ .Chart.Name }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+{{- end }}
+
+# Metric collector selector labels
+{{- define "pi-agent.collector.selectorLabels" -}}
+app.kubernetes.io/component: {{ .Values.collector.name }}
+{{- end }}

helm/pi-agent/templates/daemonset.yaml

@@ -0,0 +1,31 @@
+# Metric collector template
+apiVersion: apps/v1
+kind: DaemonSet
+metadata:
+  name: {{ .Values.collector.name }}
+  namespace: {{ .Release.namespace }}
+  labels: {{- include "pi-agent.labels" . | nindent 4 }}
+spec:
+  selector:
+    matchLabels:
+      {{- include "pi-agent.collector.selectorLabels" . | nindent 6 }}
+  template:
+    metadata:
+      labels:
+        {{- include "pi-agent.collector.selectorLabels" . | nindent 8 }}
+    spec:
+      containers:
+        - name: {{ .Chart.Name }}
+          image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          volumeMounts:
+          - name: sysfs
+            mountPath: /host/sys
+            readOnly: true
+      tolerations:
+      # Run on all nodes including control plane
+      - operator: Exists
+      volumes:
+      - name: sysfs
+        hostPath:
+          path: /sys

helm/pi-agent/values.yaml

@@ -1,6 +1,17 @@
-schedule: "*/5 * * * *"
-
+# Image configuration
 image:
   repository: ghcr.io/amfelso/pi-agent
   tag: latest
   pullPolicy: IfNotPresent
+
+# Metric collector configuration
+collector:
+  name: metric-collector
+  schedule: 300 # Default collection interval = every 5 minutes
+  resources:
+    limits:
+      cpu: 500m
+      memory: 256Mi
+    requests:
+      cpu: 100m
+      memory: 128Mi