feat: bootstrap service monitor (#5)

* feat: added template configuration for service monitors * docs: added note that ServiceMonitor resources are created as well * fix: align service monitor endpoints value source with property key * chore: align property key with template config
tagesspiegel · Jan 9, 2024 · 99edfbd · 99edfbd
1 parent 50fe021
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diff --git a/README.md b/README.md
@@ -1,6 +1,6 @@
 # helm-plugin-bootstrap
 
-A plugin for [Helm](https://helm.sh/) to add additional files to your Helm chart. This plugin adds resources such as `PodDisruptionBudget`, `NetworkPoliciy` in the same way as the other files are created during helm create.
+A plugin for [Helm](https://helm.sh/) to add additional files to your Helm chart. This plugin adds resources such as `PodDisruptionBudget`, `NetworkPoliciy`, `ServiceMonitor` in the same way as the other files are created during helm create.
 
 ## Installation
 

diff --git a/internal/bootstrap/bootstrap.go b/internal/bootstrap/bootstrap.go
@@ -106,23 +106,30 @@ func Bootstrap(chartLocation string, force bool) error {
 
 	files := []struct {
 		path        string
-		content     []byte
+		content     string
 		propertyKey string
-		values      []byte
+		values      string
 	}{
 		{
 			// pdb.yaml
 			path:        filepath.Join(templateFolderLocation, PodDisruptionBudgetFileName),
-			content:     []byte(fmt.Sprintf(pdbTemplate, metadata.Name)),
+			content:     pdbTemplate,
 			propertyKey: "pdb",
-			values:      []byte(pdbValuesYaml),
+			values:      pdbValuesYaml,
 		},
 		{
 			// networkpolicy.yaml
 			path:        filepath.Join(templateFolderLocation, NetworkPolicyFileName),
-			content:     []byte(fmt.Sprintf(networkPolicy, metadata.Name)),
+			content:     networkPolicyTemplate,
 			propertyKey: "networkPolicy",
-			values:      []byte(networkPolicyValuesYaml),
+			values:      networkPolicyValuesYaml,
+		},
+		{
+			// servicemonitor.yaml
+			path:        filepath.Join(templateFolderLocation, ServiceMonitorFileName),
+			content:     serviceMonitorTemplate,
+			propertyKey: "metrics",
+			values:      serviceMonitorValuesYaml,
 		},
 	}
 	// write files
@@ -131,12 +138,12 @@ func Bootstrap(chartLocation string, force bool) error {
 			// There is no handle to a preferred output stream here.
 			fmt.Fprintf(os.Stderr, "WARNING: File %q already exists. Overwriting.\n", file.path)
 		}
-		if err := os.WriteFile(file.path, file.content, 0644); err != nil {
+		if err := os.WriteFile(file.path, []byte(fmt.Sprintf(file.content, metadata.Name, file.propertyKey)), 0644); err != nil {
 			return err
 		}
 		// write values.yaml if there is content
 		if len(file.values) > 0 && (!bytes.Contains(valuesData, []byte(file.propertyKey)) || force) {
-			valuesData = append(valuesData, []byte(file.values)...)
+			valuesData = append(valuesData, []byte(fmt.Sprintf(file.values, file.propertyKey))...)
 		}
 	}
 	// write values.yaml

diff --git a/internal/bootstrap/files.go b/internal/bootstrap/files.go
@@ -5,33 +5,36 @@ const (
 	PodDisruptionBudgetFileName = "pdb.yaml"
 	// NetworkPolicyFileName is the name of the file that will be created in the templates folder
 	NetworkPolicyFileName = "networkpolicy.yaml"
+	// ServiceMonitorFileName is the name of the file that will be created in the templates folder
+	ServiceMonitorFileName = "servicemonitor.yaml"
 )
 
-const pdbTemplate = `{{- if .Values.pdb.enabled }}
+// manifest templates
+
+const pdbTemplate = `{{- if .Values.%[2]s.enabled }}
 apiVersion: policy/v1
 kind: PodDisruptionBudget
 metadata:
   name: {{ include "%[1]s.fullname" . }}
   labels:
     {{- include "%[1]s.labels" . | nindent 4 }}
-  {{- with .Values.pdb.annotations }}
+  {{- with .Values.%[2]s.annotations }}
   annotations:
     {{- toYaml . | nindent 4 }}
   {{- end }}
 spec:
-  {{- with .Values.pdb.maxUnavailable }}
+  {{- with .Values.%[2]s.maxUnavailable }}
   maxUnavailable: {{ . }}
   {{- end }}
-  {{- with .Values.pdb.minAvailable }}
+  {{- with .Values.%[2]s.minAvailable }}
   minAvailable: {{ . }}
   {{- end }}
   selector:
     matchLabels:
-	{{- include "%[1]s.selectorLabels" . | nindent 6 }}
+	    {{- include "%[1]s.selectorLabels" . | nindent 6 }}
 {{- end }}
 `
-
-const networkPolicy = `{{- if .Values.networkPolicy.enabled }}
+const networkPolicyTemplate = `{{- if .Values.%[2]s.enabled }}
 apiVersion: networking.k8s.io/v1
 kind: NetworkPolicy
 metadata:
@@ -43,32 +46,59 @@ spec:
     matchLabels:
       {{- include "%[1]s.selectorLabels" . | nindent 6 }}
   policyTypes:
-  {{- if .Values.networkPolicy.ingress }}
+  {{- if .Values.%[2]s.ingress }}
     - Ingress
   {{- end }}
-  {{- if .Values.networkPolicy.egress }}
+  {{- if .Values.%[2]s.egress }}
     - Egress
   {{- end }}
-  {{- with .Values.networkPolicy.ingress }}
+  {{- with .Values.%[2]s.ingress }}
   ingress:
     {{- toYaml . | nindent 4 }}
   {{- end }}
-  {{- with .Values.networkPolicy.egress }}
+  {{- with .Values.%[2]s.egress }}
   egress:
     {{- toYaml . | nindent 4 }}
   {{- end -}}
 {{- end }}
 `
+const serviceMonitorTemplate = `{{- if and .Values.%[1]s.enabled .Values.%[1]s.serviceMonitor.enabled }}
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: {{ template "%[1]s.fullname" . }}
+  {{- if .Values.%[2]s.serviceMonitor.namespace }}
+  namespace: {{ .Values.%[2]s.serviceMonitor.namespace }}
+  {{- end }}
+  labels:
+    {{- include "%[1]s.labels" . | nindent 4 }}
+spec:
+  endpoints:
+    - port: {{ .Values.service.port }}
+      path: {{ .Values.%[2]s.serviceMonitor.metricsPath }}
+      {{- with .Values.%[2]s.serviceMonitor.interval }}
+      interval: {{ . }}
+      {{- end }}
+      {{- with .Values.%[2]s.serviceMonitor.scrapeTimeout }}
+      scrapeTimeout: {{ . }}
+      {{- end }}
+  selector:
+    matchLabels:
+      {{- include "%[1]s.selectorLabels" . | nindent 6 }}
+{{- end }}
+`
+
+// values.yaml configurations
 
 const pdbValuesYaml = `
-pdb:
+%[1]s:
   enabled: true
   annotations: {}
   minAvailable: 1
   maxUnavailable: 0
 `
 const networkPolicyValuesYaml = `
-networkPolicy:
+%[1]s:
   enabled: false
   ingress: []
     # - from:
@@ -93,3 +123,13 @@ networkPolicy:
     #     - protocol: UDP
     #       port: 53
 `
+const serviceMonitorValuesYaml = `
+%[1]s:
+  enabled: false
+  serviceMonitor:
+    enabled: false
+    metricsPath: /metrics
+    namespace: ""
+    interval: ""
+    scrapeTimeout: ""
+`