MSP-72 Converted to dns-canary to helm chart

.gitignore

@@ -2,3 +2,4 @@
 /charts/*/charts
 .idea
 test.yaml
+.DS_Store

charts/dns-canary/Chart.yaml

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+apiVersion: v2
+name: dns-canary
+description: A Helm chart for Kubernetes
+
+# A chart can be either an 'application' or a 'library' chart.
+#
+# Application charts are a collection of templates that can be packaged into versioned archives
+# to be deployed.
+#
+# Library charts provide useful utilities or functions for the chart developer. They're included as
+# a dependency of application charts to inject those utilities and functions into the rendering
+# pipeline. Library charts do not define any templates and therefore cannot be deployed.
+type: application
+
+# This is the chart version. This version number should be incremented each time you make changes
+# to the chart and its templates, including the app version.
+# Versions are expected to follow Semantic Versioning (https://semver.org/)
+version: 0.1.0
+
+# This is the version number of the application being deployed. This version number should be
+# 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"

charts/dns-canary/README.md

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+# DNS Canary Helm Chart
+
+This Helm chart deploys a DNS Canary CronJob to your Kubernetes cluster.  
+The canary continuously tests internal service discovery and optionally pushes logs to CloudWatch and sends alerts via SNS.
+
+## Installation Example
+
+```bash
+helm install dns-canary ./dns-canary -f values.yaml

charts/dns-canary/templates/_helpers.tpl

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+{{/*
+Expand the name of the chart.
+*/}}
+{{- define "dns-canary.name" -}}
+{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Create a default fully qualified app name.
+We truncate at 63 chars because some Kubernetes name fields are limited to this (by the DNS naming spec).
+If release name contains chart name it will be used as a full name.
+*/}}
+{{- define "dns-canary.fullname" -}}
+{{- if .Values.fullnameOverride }}
+{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- $name := default .Chart.Name .Values.nameOverride }}
+{{- if contains $name .Release.Name }}
+{{- .Release.Name | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
+{{- end }}
+{{- end }}
+{{- end }}
+
+{{/*
+Create chart name and version as used by the chart label.
+*/}}
+{{- define "dns-canary.chart" -}}
+{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Common labels
+*/}}
+{{- define "dns-canary.labels" -}}
+helm.sh/chart: {{ include "dns-canary.chart" . }}
+{{ include "dns-canary.selectorLabels" . }}
+{{- if .Chart.AppVersion }}
+app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
+{{- end }}
+app.kubernetes.io/managed-by: {{ .Release.Service }}
+{{- end }}
+
+{{/*
+Selector labels
+*/}}
+{{- define "dns-canary.selectorLabels" -}}
+app.kubernetes.io/name: {{ include "dns-canary.name" . }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+{{- end }}
+
+{{/*
+Create the name of the service account to use
+*/}}
+{{- define "dns-canary.serviceAccountName" -}}
+{{- if .Values.serviceAccount.create }}
+{{- default (include "dns-canary.fullname" .) .Values.serviceAccount.name }}
+{{- else }}
+{{- default "default" .Values.serviceAccount.name }}
+{{- end }}
+{{- end }}

charts/dns-canary/templates/cronjob.yaml

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+apiVersion: batch/v1
+kind: CronJob
+metadata:
+  name: {{ include "dns-canary.fullname" . }}
+  labels:
+    {{- include "dns-canary.labels" . | nindent 4 }}
+    app: {{ .Values.name }}
+spec:
+  schedule: {{ .Values.schedule | quote }}
+  concurrencyPolicy: Allow
+  failedJobsHistoryLimit: 1
+  successfulJobsHistoryLimit: 3
+  suspend: false
+  jobTemplate:
+    spec:
+      backoffLimit: 6
+      completions: 1
+      parallelism: 1
+      template:
+        metadata:
+          labels:
+            {{- include "dns-canary.selectorLabels" . | nindent 12 }}
+            app: {{ .Values.name }}
+        spec:
+          restartPolicy: OnFailure
+          {{- with .Values.imagePullSecrets }}
+          imagePullSecrets:
+            {{- toYaml . | nindent 12 }}
+          {{- end }}
+          serviceAccountName: {{ include "dns-canary.serviceAccountName" . }}
+          securityContext:
+            {{- toYaml .Values.podSecurityContext | nindent 12 }}
+          containers:
+            - name: {{ .Chart.Name }}
+              securityContext:
+                {{- toYaml .Values.securityContext | nindent 16 }}
+              image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
+              imagePullPolicy: {{ .Values.image.pullPolicy }}
+              command:
+                - /bin/sh
+                - -c
+                - |
+                  set -e
+                  TARGET="{{ .Values.targetService }}"
+                  echo "$(date) Checking DNS resolution for $TARGET"
+
+                  if nslookup $TARGET; then
+                    echo "$(date) DNS Canary check passed for $TARGET"
+                  else
+                    echo "$(date) DNS Canary check failed for $TARGET" >&2
+
+                    if [ -n "{{`{{ .Values.cloudwatchLogGroup }}`}}" ]; then
+                      echo "Sending failure log to CloudWatch"
+                      aws logs put-log-events \
+                        --log-group-name "{{`{{ .Values.cloudwatchLogGroup }}`}}" \
+                        --log-stream-name "dns-canary-{{`{{ .Values.name }}`}}" \
+                        --log-events "timestamp=$(date +%s%3N),message=\"DNS Canary failure: $TARGET\""
+                    fi
+
+                    if [ -n "{{`{{ .Values.alertSnsTopicArn }}`}}" ]; then
+                      echo "Triggering SNS alert"
+                      aws sns publish \
+                        --topic-arn "{{`{{ .Values.alertSnsTopicArn }}`}}" \
+                        --message "DNS Canary failure detected for $TARGET in cluster {{`{{ .Values.clusterName }}`}}"
+                    fi
+                  fi
+              resources:
+                {{- toYaml .Values.resources | nindent 16 }}
+              {{- with .Values.volumeMounts }}
+              volumeMounts:
+                {{- toYaml . | nindent 16 }}
+              {{- end }}
+          {{- with .Values.volumes }}
+          volumes:
+            {{- toYaml . | nindent 12 }}
+          {{- end }}
+          {{- with .Values.nodeSelector }}
+          nodeSelector:
+            {{- toYaml . | nindent 12 }}
+          {{- end }}
+          {{- with .Values.affinity }}
+          affinity:
+            {{- toYaml . | nindent 12 }}
+          {{- end }}
+          {{- with .Values.tolerations }}
+          tolerations:
+            {{- toYaml . | nindent 12 }}
+          {{- end }}

charts/dns-canary/templates/serviceaccount.yaml

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+{{- if .Values.serviceAccount.create -}}
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ include "dns-canary.serviceAccountName" . }}
+  labels:
+    {{- include "dns-canary.labels" . | nindent 4 }}
+  {{- with .Values.serviceAccount.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+automountServiceAccountToken: {{ .Values.serviceAccount.automount }}
+{{- end }}

charts/dns-canary/values.yaml

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+# Default values for dns-canary.
+# This is a YAML-formatted file.
+# Declare variables to be passed into your templates.
+
+targetService: kubernetes.default.svc.cluster.local
+
+# Scheduled to run cronjob every 20 minutes.
+schedule: "*/20 * * * *"
+
+# This will set the replicaset count more information can be found here: https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/
+replicaCount: 1
+
+# This sets the container image more information can be found here: https://kubernetes.io/docs/concepts/containers/images/
+image:
+  repository: busybox
+  # This sets the pull policy for images.
+  pullPolicy: IfNotPresent
+  # Overrides the image tag whose default is the chart appVersion.
+  tag: "1.37"
+
+# This is for the secretes for pulling an image from a private repository more information can be found here: https://kubernetes.io/docs/tasks/configure-pod-container/pull-image-private-registry/
+imagePullSecrets: []
+# This is to override the chart name.
+nameOverride: ""
+fullnameOverride: ""
+
+# This section builds out the service account more information can be found here: https://kubernetes.io/docs/concepts/security/service-accounts/
+serviceAccount:
+  # Specifies whether a service account should be created
+  create: true
+  # Automatically mount a ServiceAccount's API credentials?
+  automount: true
+  # Annotations to add to the service account
+  annotations: {}
+  # The name of the service account to use.
+  # If not set and create is true, a name is generated using the fullname template
+  name: ""
+
+# This is for setting Kubernetes Annotations to a Pod.
+# For more information checkout: https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/
+podAnnotations: {}
+# This is for setting Kubernetes Labels to a Pod.
+# For more information checkout: https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/
+podLabels: {}
+
+podSecurityContext: {}
+  # fsGroup: 2000
+
+securityContext: {}
+  # capabilities:
+  #   drop:
+  #   - ALL
+  # readOnlyRootFilesystem: true
+  # runAsNonRoot: true
+  # runAsUser: 1000
+
+resources: {}
+  # We usually recommend not to specify default resources and to leave this as a conscious
+  # choice for the user. This also increases chances charts run on environments with little
+  # resources, such as Minikube. If you do want to specify resources, uncomment the following
+  # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
+  # limits:
+  #   cpu: 100m
+  #   memory: 128Mi
+  # requests:
+  #   cpu: 100m
+  #   memory: 128Mi
+
+# Additional volumes on the output Deployment definition.
+volumes: []
+# - name: foo
+#   secret:
+#     secretName: mysecret
+#     optional: false
+
+# Additional volumeMounts on the output Deployment definition.
+volumeMounts: []
+# - name: foo
+#   mountPath: "/etc/foo"
+#   readOnly: true
+
+nodeSelector: {}
+
+tolerations: []
+
+affinity: {}