# Create a directory to hold the chart project
mkdir workload-helm
# Create a workload-helm/Chart.yaml
cat <<EOF > workload-helm/Chart.yaml
apiVersion: v2
appVersion: 0.3.0
description: A helm chart to provision standard workloads.
name: workload
type: application
version: 0.3.0
EOF
# Create a workload-helm/values.yaml
cat <<EOF > workload-helm/values.yaml
service:
  type: ClusterIP
  ports:
    - name: www
      protocol: TCP
      port: 80
      targetPort: 80

containers:
  my-container:
    image:
      name: busybox:latest
    command: ["/bin/echo"]
    args: 
      - "-c"
      - "Hello World!"
    resources:
      limits:
        cpu: 100m
        memory: 128Mi
      requests:
        cpu: 100m
        memory: 128Mi
EOF

# Create a directory to hold templates
mkdir workload-helm/templates
# Create a workload-helm/templates/helpers.tpl
cat <<EOF > workload-helm/templates/helpers.tpl
{{/*
Expand the name of the chart.
*/}}
{{- define "workload.name" -}}
{{- default .Release.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 "workload.fullname" -}}
{{- \$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 }}
{{/*
Create chart name and version as used by the chart label.
*/}}
{{- define "workload.chart" -}}
{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" }}
{{- end }}
{{/*
Common labels
*/}}
{{- define "workload.labels" -}}
helm.sh/chart: {{ include "workload.chart" . }}
{{ include "workload.selectorLabels" . }}
{{- if .Chart.AppVersion }}
app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
{{- end }}
app.kubernetes.io/managed-by: {{ .Release.Service }}
{{- end }}
{{/*
Selector labels
*/}}
{{- define "workload.selectorLabels" -}}
app.kubernetes.io/name: {{ include "workload.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
{{- end }}
EOF
cat <<EOF > workload-helm/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "workload.name" . }}
  labels:
    {{- include "workload.labels" . | nindent 4 }}
spec:
  selector:
    matchLabels:
      {{- include "workload.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      labels:
        {{- include "workload.selectorLabels" . | nindent 8 }}
    spec:
      containers:
        {{- range \$name, \$container := .Values.containers }}
        - name: {{ \$name }}
          image: "{{ $container.image.name }}"
          {{- with \$container.command }}
          command:
            {{- toYaml \$container.command | nindent 12 }}
          {{- end }}
          {{- with \$container.args }}
          args:
            {{- toYaml \$container.args | nindent 12 }}
          {{- end }}
          {{- with \$container.env }}
          env:
            {{- toYaml \$container.env | nindent 12 }}
          {{- end }}
          {{- with \$container.volumeMounts }}
          volumeMounts:
            {{- toYaml \$container.volumeMounts | nindent 12 }}
          {{- end }}
          {{- with \$container.livenessProbe }}
          livenessProbe:
            {{- toYaml \$container.livenessProbe | nindent 12 }}
          {{- end }}
          {{- with \$container.readinessProbe }}
          readinessProbe:
            {{- toYaml \$container.readinessProbe | nindent 12 }}
          {{- end }}
          {{- with \$container.resources }}
          resources:
            {{- toYaml \$container.resources | nindent 12 }}
          {{- end }}
        {{- end }}
EOF
cat <<EOF > workload-helm/templates/service.yaml
{{ if .Values.service }}
apiVersion: v1
kind: Service
metadata:
  name: {{ include "workload.name" . }}
  labels:
    {{- include "workload.labels" . | nindent 4 }}
spec:
  type: {{ .Values.service.type }}
  selector:
    {{- include "workload.selectorLabels" . | nindent 4 }}
  {{- with .Values.service.ports }}
  ports:
    {{- toYaml . | nindent 4 }}
  {{- end }}
{{- end }}
EOF

helm template workload-helm

# Create a directory to hold the KCL project
mkdir workload-kcl
# Create a workload-kcl/kcl.yaml
cat <<EOF > workload-kcl/kcl.yaml
kcl_options:
  - key: containers
    value:
      my-container:
        image:
          name: busybox:latest
        command: ["/bin/echo"]
        args: 
          - "-c"
          - "Hello World!"
        resources:
          limits:
            cpu: 100m
            memory: 128Mi
          requests:
            cpu: 100m
            memory: 128Mi

  - key: service
    value:
      type: ClusterIP
      ports:
        - name: www
          protocol: TCP
          port: 80
          targetPort: 80
EOF

# Create a workload-kcl/deployment.k
cat <<EOF > workload-kcl/deployment.k
apiVersion = "apps/v1"
kind = "Deployment"
metadata = {
    name = "release-name"
    labels = {
        "app.kubernetes.io/name" = "release-name"
        "app.kubernetes.io/instance" = "release-name"
    }
}
spec = {
    selector.matchLabels = metadata.labels
    template.metadata.labels = metadata.labels
    template.spec.containers = [
        {
            name = name
            image = container.image.name
            command = container.command
            command = container.args
            env = container.env
            resources = container.resources
        } for name, container in option("containers") or {}
    ]
}
EOF
cat <<EOF > workload-kcl/service.k
apiVersion = "v1"
kind = "Service"
metadata = {
    name = "release-name"
    labels = {
        "app.kubernetes.io/name" = "release-name"
        "app.kubernetes.io/instance" = "release-name"
    }
}
spec = {
    selector.matchLabels = metadata.labels
    type = option("service", default={})?.type
    ports = option("service", default={})?.ports
}
EOF

# Create a directory to hold the base
mkdir base
# Create a base/deployment.yaml
cat <<EOF > base/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ldap
  labels:
    app: ldap
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ldap
  template:
    metadata:
      labels:
        app: ldap
    spec:
      containers:
        - name: ldap
          image: osixia/openldap:1.1.11
          args: ["--copy-service"]
          volumeMounts:
            - name: ldap-data
              mountPath: /var/lib/ldap
          ports:
            - containerPort: 389
              name: openldap
      volumes:
        - name: ldap-data
          emptyDir: {}
EOF
# Create a base/kustomization.yaml
cat <<EOF > base/kustomization.yaml
resources:
- deployment.yaml
EOF

# Create a directory to hold the prod overlay
mkdir prod
# Create a prod/deployment.yaml
cat <<EOF > prod/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ldap
spec:
  replicas: 6
  template:
    spec:
      volumes:
        - name: ldap-data
          emptyDir: null
          gcePersistentDisk:
            readOnly: true
            pdName: ldap-persistent-storage
EOF
cat <<EOF > prod/kustomization.yaml
resources:
  - ../base
patchesStrategicMerge:
  - deployment.yaml
EOF

diff \
  <(kcl main.k) \
  <(kcl main.k -D env=prod) |\
  more

# Generate base deployment
kcl main.k -o deployment.yaml
# Generate prod deployment
kcl main.k -o prod-deployment.yaml -D env=prod
# Diff prod deployment and base deployment
diff prod-deployment.yaml deployment.yaml