Helm vs Kustomize vs ArgoCD: K8s Deployment Tools

# values.yaml - Configuration file
replicaCount: 3
image:
  repository: nginx
  tag: "1.21"
  pullPolicy: IfNotPresent

service:
  type: ClusterIP
  port: 80

ingress:
  enabled: true
  annotations:
    kubernetes.io/ingress.class: nginx
  hosts:
    - host: myapp.example.com
      paths:
        - path: /
          pathType: Prefix

resources:
  limits:
    cpu: 500m
    memory: 512Mi
  requests:
    cpu: 250m
    memory: 256Mi

# templates/deployment.yaml - Template file
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "myapp.fullname" . }}
  labels:
    {{- include "myapp.labels" . | nindent 4 }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      {{- include "myapp.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      labels:
        {{- include "myapp.selectorLabels" . | nindent 8 }}
    spec:
      containers:
      - name: {{ .Chart.Name }}
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
        imagePullPolicy: {{ .Values.image.pullPolicy }}
        ports:
        - name: http
          containerPort: 80
          protocol: TCP
        resources:
          {{- toYaml .Values.resources | nindent 12 }}

# base/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

resources:
- deployment.yaml
- service.yaml
- configmap.yaml

commonLabels:
  app: myapp
  version: "1.0"

images:
- name: nginx
  newTag: "1.21"

# overlays/production/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

namespace: production

resources:
- ../../base

patchesStrategicMerge:
- deployment-patch.yaml
- ingress.yaml

replicas:
- name: myapp
  count: 5

images:
- name: nginx
  newTag: "1.21.3"

# overlays/production/deployment-patch.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  template:
    spec:
      containers:
      - name: myapp
        resources:
          limits:
            cpu: 1000m
            memory: 1Gi
          requests:
            cpu: 500m
            memory: 512Mi

# application.yaml - ArgoCD Application
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: myapp-production
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/company/k8s-configs
    targetRevision: main
    path: apps/myapp/overlays/production
  destination:
    server: https://kubernetes.default.svc
    namespace: production
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
    - CreateNamespace=true
    retry:
      limit: 5
      backoff:
        duration: 5s
        factor: 2
        maxDuration: 3m

# Advanced Helm templating
{{- define "myapp.name" -}}
{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
{{- end }}

{{- define "myapp.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 }}

# Conditional resource creation
{{- if .Values.ingress.enabled -}}
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: {{ include "myapp.fullname" . }}
  {{- with .Values.ingress.annotations }}
  annotations:
    {{- toYaml . | nindent 4 }}
  {{- end }}
spec:
  {{- if .Values.ingress.tls }}
  tls:
    {{- range .Values.ingress.tls }}
    - hosts:
        {{- range .hosts }}
        - {{ . | quote }}
        {{- end }}
      secretName: {{ .secretName }}
    {{- end }}
  {{- end }}
  rules:
    {{- range .Values.ingress.hosts }}
    - host: {{ .host | quote }}
      http:
        paths:
          {{- range .paths }}
          - path: {{ .path }}
            pathType: {{ .pathType }}
            backend:
              service:
                name: {{ include "myapp.fullname" $ }}
                port:
                  number: {{ $.Values.service.port }}
          {{- end }}
    {{- end }}
{{- end }}

# Complex patch operations
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

patchesStrategicMerge:
- deployment-resources.yaml
- service-patch.yaml

patchesJson6902:
- target:
    group: apps
    version: v1
    kind: Deployment
    name: myapp
  path: deployment-patch.yaml

# JSON patch for complex modifications
- op: add
  path: /spec/template/spec/containers/0/env/-
  value:
    name: ENVIRONMENT
    value: production
- op: replace
  path: /spec/template/spec/containers/0/image
  value: myapp:v2.1.0

# ApplicationSet for multi-environment deployment
apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: myapp-environments
  namespace: argocd
spec:
  generators:
  - git:
      repoURL: https://github.com/company/k8s-configs
      revision: HEAD
      directories:
      - path: apps/myapp/overlays/*
  template:
    metadata:
      name: 'myapp-{{path.basename}}'
    spec:
      project: default
      source:
        repoURL: https://github.com/company/k8s-configs
        targetRevision: HEAD
        path: '{{path}}'
      destination:
        server: https://kubernetes.default.svc
        namespace: '{{path.basename}}'
      syncPolicy:
        automated:
          prune: true
          selfHeal: true

# Chart development and testing
helm create myapp
helm template myapp ./myapp --values values-dev.yaml
helm lint ./myapp

# Multi-environment deployment
helm upgrade --install myapp-dev ./myapp \
  --namespace development \
  --values values-dev.yaml \
  --dry-run

helm upgrade --install myapp-prod ./myapp \
  --namespace production \
  --values values-prod.yaml \
  --timeout 10m \
  --wait

# Release management
helm list --all-namespaces
helm history myapp-prod
helm rollback myapp-prod 3

# Build and preview configurations
kustomize build overlays/development
kustomize build overlays/production > manifests.yaml

# Direct application
kubectl apply -k overlays/development
kubectl apply -k overlays/production

# Integration with kubectl
kubectl kustomize overlays/production | kubectl apply -f -
kubectl kustomize overlays/production | kubectl diff -f -

# Application management
argocd app create myapp-prod \
  --repo https://github.com/company/k8s-configs \
  --path apps/myapp/overlays/production \
  --dest-server https://kubernetes.default.svc \
  --dest-namespace production \
  --sync-policy automated

# Sync and monitoring
argocd app sync myapp-prod
argocd app get myapp-prod
argocd app diff myapp-prod
argocd app history myapp-prod

# Helm hooks for database migration
apiVersion: batch/v1
kind: Job
metadata:
  name: "{{ include "myapp.fullname" . }}-migration"
  annotations:
    "helm.sh/hook": pre-upgrade
    "helm.sh/hook-weight": "-5"
    "helm.sh/hook-delete-policy": before-hook-creation
spec:
  template:
    spec:
      restartPolicy: Never
      containers:
      - name: migration
        image: "{{ .Values.migration.image }}"
        command: ["migrate", "up"]

# Custom transformers
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

transformers:
- labelTransformer.yaml
- prefixSuffixTransformer.yaml

generators:
- secretGenerator.yaml
- configMapGenerator.yaml

# Label transformer
apiVersion: builtin
kind: LabelTransformer
metadata:
  name: labels
labels:
  environment: production
  team: platform
fieldSpecs:
- path: metadata/labels
  create: true

# Rollout strategy with ArgoCD
apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: myapp
spec:
  replicas: 10
  strategy:
    canary:
      steps:
      - setWeight: 10
      - pause: {duration: 60s}
      - setWeight: 50
      - pause: {duration: 60s}
      - analysis:
          templates:
          - templateName: success-rate
          args:
          - name: service-name
            value: myapp
      - setWeight: 100
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: myapp:{{.Values.image.tag}}

# Chart.yaml with security metadata
apiVersion: v2
name: myapp
version: 1.2.3
description: Secure application deployment
home: https://github.com/company/myapp
sources:
- https://github.com/company/myapp
maintainers:
- name: Platform Team
  email: platform@company.com
annotations:
  artifacthub.io/signKey: |
    -----BEGIN PGP PUBLIC KEY BLOCK-----
    ...
  artifacthub.io/license: MIT

# ArgoCD RBAC policy
apiVersion: v1
kind: ConfigMap
metadata:
  name: argocd-rbac-cm
  namespace: argocd
data:
  policy.default: role:readonly
  policy.csv: |
    p, role:admin, applications, *, */*, allow
    p, role:developer, applications, get, team-alpha/*, allow
    p, role:developer, applications, sync, team-alpha/*, allow
    g, team-alpha:admins, role:admin
    g, team-alpha:developers, role:developer

# GitHub Actions with Helm
name: Deploy with Helm
on:
  push:
    branches: [main]
jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v3
    - name: Configure AWS credentials
      uses: aws-actions/configure-aws-credentials@v2
    - name: Deploy with Helm
      run: |
        helm upgrade --install myapp ./chart \
          --namespace production \
          --values values-prod.yaml \
          --set image.tag=${{ github.sha }}

# GitLab CI with Kustomize
stages:
  - build
  - deploy

deploy:
  stage: deploy
  script:
    - cd overlays/production
    - kustomize edit set image myapp:$CI_COMMIT_SHA
    - kustomize build . | kubectl apply -f -
  only:
    - main

# ArgoCD with Prometheus metrics
apiVersion: v1
kind: ConfigMap
metadata:
  name: argocd-cmd-params-cm
data:
  application.instanceLabelKey: argocd.argoproj.io/instance
  server.metrics.enabled: "true"
  controller.metrics.enabled: "true"

# Helm excels in package management
helm repo add stable https://charts.helm.sh/stable
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm install monitoring prometheus-community/kube-prometheus-stack

# Kustomize integrates seamlessly with kubectl
kubectl apply -k overlays/production
kubectl diff -k overlays/production

# ArgoCD for comprehensive GitOps
apiVersion: argoproj.io/v1alpha1
kind: AppProject
metadata:
  name: production
spec:
  description: Production applications
  sourceRepos:
  - 'https://github.com/company/*'
  destinations:
  - namespace: 'production'
    server: https://kubernetes.default.svc
  clusterResourceWhitelist:
  - group: ''
    kind: Namespace
  roles:
  - name: admin
    policies:
    - p, proj:production:admin, applications, *, production/*, allow

# ArgoCD managing Helm charts
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: myapp-helm
spec:
  source:
    repoURL: https://github.com/company/helm-charts
    path: myapp
    targetRevision: HEAD
    helm:
      valueFiles:
      - values-production.yaml
      parameters:
      - name: image.tag
        value: v2.1.0

# ArgoCD with Kustomize builds
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: myapp-kustomize
spec:
  source:
    repoURL: https://github.com/company/k8s-manifests
    path: apps/myapp/overlays/production
    targetRevision: HEAD