drunk.charts

Drunk-lib Library Chart Reference

The drunk-lib Helm chart library provides a comprehensive collection of reusable templates for Kubernetes applications. It serves as the foundation for the drunk-app chart and can be used by any Helm chart that needs standardized, production-ready Kubernetes resources.

Overview
Architecture
Available Templates
Template Reference
Usage Examples
Extending the Library
Contributing

Overview

Purpose

Drunk-lib eliminates the need to write repetitive Kubernetes resource templates by providing:

Standardized Templates: Production-ready templates following best practices
Flexible Configuration: Comprehensive configuration options for all use cases
Consistency: Uniform resource generation across all applications
Maintainability: Centralized template management and updates

Key Benefits

🔄 Reusability: Use the same templates across multiple charts
📋 Standards: Built-in Kubernetes best practices
🛠 Flexibility: Extensive configuration options
🧩 Modularity: Include only the resources you need
🔧 Maintainability: Single source of truth for templates

Architecture

Library Chart Structure

drunk-lib/
├── Chart.yaml                 # Chart metadata (type: library)
├── values.yaml               # Default configuration values
└── templates/
    ├── _helpers.tpl          # Helper functions and labels
    ├── _deployment.tpl       # Deployment template
    ├── _statefulset.tpl      # StatefulSet template
    ├── _service.tpl          # Service template
    ├── _ingress.tpl          # Ingress template
    ├── _gateway.tpl          # Gateway API Gateway template
    ├── _httproute.tpl        # Gateway API HTTPRoute template
    ├── _configMap.tpl        # ConfigMap template
    ├── _secrets.tpl          # Secret template
    ├── _secretprovider.tpl   # Azure Key Vault SecretProviderClass
    ├── _serviceAccount.tpl   # ServiceAccount template
    ├── _volumes.tpl          # PersistentVolumeClaim templates
    ├── _cronjob.tpl          # CronJob template
    ├── _job.tpl              # Job template
    ├── _hpa.tpl              # HorizontalPodAutoscaler template
    └── _tls-secrets.tpl      # TLS Secret template

Template Naming Convention

All templates follow the naming pattern: drunk-lib.<resource-type>

Examples:

drunk-lib.deployment
drunk-lib.service
drunk-lib.configMap

Available Templates

Core Resources

Template	Purpose	Template Name
Deployment	Standard application deployment	`drunk-lib.deployment`
StatefulSet	Stateful application deployment	`drunk-lib.statefulSet`
Service	Service discovery and load balancing	`drunk-lib.service`
Ingress	External access routing (traditional)	`drunk-lib.ingress`
Gateway	External access via Gateway API	`drunk-lib.gateway`
HTTPRoute	HTTP routing rules for Gateway API	`drunk-lib.httpRoute`

Configuration Resources

Template	Purpose	Template Name
ConfigMap	Application configuration	`drunk-lib.configMap`
Secret	Sensitive configuration	`drunk-lib.secrets`
SecretProviderClass	Azure Key Vault integration	`drunk-lib.secretProvider`
TLS Secret	TLS certificate storage	`drunk-lib.tlsSecrets`

Storage Resources

Template	Purpose	Template Name
PersistentVolumeClaim	Persistent storage	`drunk-lib.volumes`

Batch Resources

Template	Purpose	Template Name
CronJob	Scheduled jobs	`drunk-lib.cronJobs`
Job	One-time jobs	`drunk-lib.jobs`

Scaling & Security

Template	Purpose	Template Name
HPA	Horizontal Pod Autoscaler	`drunk-lib.hpa`
ServiceAccount	Pod identity	`drunk-lib.serviceAccount`
ImagePullSecret	Registry authentication	`drunk-lib.imagePullSecret`
NetworkPolicy	Network access control	`drunk-lib.networkPolicies`

Template Reference

Helper Templates

`app.name`

Returns the application name based on chart name or nameOverride.

`app.fullname`

Returns the full application name including release name.

`app.labels`

Returns standard Kubernetes labels for resources.

labels:

`app.selectorLabels`

Returns selector labels for matching pods.

selector:
  matchLabels:

Deployment Template

Template: drunk-lib.deployment

Creates a Kubernetes Deployment with comprehensive configuration options.

Key Features:

Multi-container support (main + init containers)
Flexible port configuration
Health checks (liveness/readiness probes)
Resource management
Volume mounting
Environment variable injection
Security contexts

Configuration:

deployment:
  enabled: true
  replicaCount: 1
  command: []
  args: []
  ports:
    http: 8080
    https: 8443
  liveness: "/health"
  readiness: "/ready"
  podAnnotations: {}
  
global:
  image: "myapp/image"
  tag: "latest"
  imagePullPolicy: "IfNotPresent"
  imagePullSecret: "registry-secret"

resources:
  limits:
    cpu: 500m
    memory: 512Mi
  requests:
    cpu: 100m
    memory: 128Mi

StatefulSet Template

Template: drunk-lib.statefulSet

Creates a Kubernetes StatefulSet for stateful applications.

Configuration:

statefulset:
  enabled: true
  serviceName: "my-stateful-service"
  volumeClaimTemplates:
    - name: "data"
      storage: "10Gi"
      storageClassName: "fast-ssd"
      accessModes: ["ReadWriteOnce"]

Service Template

Template: drunk-lib.service

Creates a Kubernetes Service for pod discovery and load balancing.

Configuration:

service:
  type: "ClusterIP"  # ClusterIP, NodePort, LoadBalancer
  ports:
    - name: "http"
      port: 80
      targetPort: 8080

ConfigMap Template

Template: drunk-lib.configMap

Creates a ConfigMap for application configuration.

Configuration:

configMap:
  app.properties: |
    server.port=8080
    logging.level=INFO
  config.json: |
    {"feature": "enabled"}

# Reference external ConfigMaps
configFrom:
  - "shared-config"
  - "environment-config"

Secrets Template

Template: drunk-lib.secrets

Creates a Secret for sensitive configuration.

Configuration:

secrets:
  DATABASE_PASSWORD: "secret-password"
  API_KEY: "your-api-key"

# Reference external Secrets
secretFrom:
  - "database-credentials"
  - "api-keys"

SecretProviderClass Template

Template: drunk-lib.secretProvider

Creates a SecretProviderClass for Azure Key Vault integration using the Secrets Store CSI driver.

Configuration:

secretProvider:
  enabled: true
  name: "my-key-vault-spc"
  tenantId: "your-tenant-id"
  vaultName: "your-key-vault"
  usePodIdentity: false
  useWorkloadIdentity: true
  objects:
    - objectName: "database-password"
      objectType: "secret"
    - objectName: "api-certificate"
      objectType: "cert"
  secretObjects:
    - secretName: "app-secrets"
      type: "Opaque"
      data:
        - key: "DATABASE_PASSWORD"
          objectName: "database-password"

CronJob Template

Template: drunk-lib.cronJobs

Creates CronJob resources for scheduled tasks.

Configuration:

cronJobs:
  - name: "backup"
    schedule: "0 2 * * *"
    command: ["/app/backup.sh"]
    args: ["--verbose"]
    restartPolicy: "OnFailure"
    concurrencyPolicy: "Forbid"
  - name: "cleanup"
    schedule: "0 4 * * 0"
    command: ["/app/cleanup.sh"]

Job Template

Template: drunk-lib.jobs

Creates Job resources for one-time tasks.

Configuration:

jobs:
  - name: "migration"
    command: ["/app/migrate.sh"]
    args: ["--force"]
    restartPolicy: "Never"

Volumes Template

Template: drunk-lib.volumes

Creates PersistentVolumeClaim resources for storage.

Configuration:

volumes:
  data:
    size: "10Gi"
    storageClass: "fast-ssd"
    accessMode: "ReadWriteOnce"
    mountPath: "/app/data"
  logs:
    size: "5Gi"
    mountPath: "/var/log/app"
    readOnly: false
  # EmptyDir volumes
  tmp:
    mountPath: "/tmp"
    emptyDir: true

Ingress Template

Template: drunk-lib.ingress

Creates Ingress resources for external access.

Configuration:

ingress:
  enabled: true
  className: "nginx"
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: "/"
  hosts:
    - host: "myapp.example.com"
      paths:
        - path: "/"
          pathType: "Prefix"
          port: 8080
  tls:
    - secretName: "myapp-tls"
      hosts:
        - "myapp.example.com"

HPA Template

Template: drunk-lib.hpa

Creates HorizontalPodAutoscaler for automatic scaling.

Configuration:

autoscaling:
  enabled: true
  minReplicas: 2
  maxReplicas: 10
  targetCPUUtilizationPercentage: 70
  targetMemoryUtilizationPercentage: 80

NetworkPolicy Template

Template: drunk-lib.networkPolicies

Creates NetworkPolicy resources to control network access to pods. Supports both legacy single policy and modern multiple policies configurations.

Note: Requires a CNI plugin that supports NetworkPolicy (e.g., Calico, Cilium, Weave Net).

Legacy Single Policy Configuration:

networkPolicy:
  policyTypes:
    - Ingress
  podSelector:
    app: my-app
  ingress:
    - from:
      - podSelector:
          matchLabels:
            app: frontend
      ports:
      - protocol: TCP
        port: 8080

Multiple Policies Configuration (Recommended):

networkPolicies:
  # Allow traffic from private IP ranges
  - name: allow-private-ips
    enabled: true
    policyTypes:
      - Ingress
    ingress:
      - from:
        - ipBlock:
            cidr: 10.0.0.0/8
        - ipBlock:
            cidr: 172.16.0.0/12
        - ipBlock:
            cidr: 192.168.0.0/16
        ports:
        - protocol: TCP
          port: 8080
  
  # Allow traffic from same namespace
  - name: allow-same-namespace
    enabled: true
    policyTypes:
      - Ingress
    ingress:
      - from:
        - podSelector: {}
  
  # Restrict egress to specific services
  - name: allow-egress-database
    enabled: true
    policyTypes:
      - Egress
    egress:
      - to:
        - podSelector:
            matchLabels:
              app: postgres
        ports:
        - protocol: TCP
          port: 5432

Configuration Options:

Parameter	Description	Default
`name`	Policy name	Required
`enabled`	Enable/disable this policy	`true`
`nameSuffix`	Custom suffix for resource name	`-{name}`
`podSelector`	Pod selector (defaults to app labels)	App labels
`labels`	Additional labels	`{}`
`policyTypes`	Policy types (`Ingress`, `Egress`)	Required
`ingress`	Ingress rules	`[]`
`egress`	Egress rules	`[]`

Usage Examples

Creating a Chart that Uses drunk-lib

1. Chart.yaml

apiVersion: v2
name: my-app
description: My application chart
type: application
version: 0.1.0
appVersion: "1.0"

dependencies:
  - name: drunk-lib
    version: "1.0.7"
    repository: "https://baoduy.github.io/drunk.charts/drunk-lib"

2. Template Usage

templates/deployment.yaml

templates/service.yaml

templates/configmap.yaml

3. Values Configuration

global:
  image: "myapp/image"
  tag: "v1.0.0"

deployment:
  enabled: true
  ports:
    http: 8080

configMap:
  app.properties: |
    server.port=8080
    
service:
  type: "ClusterIP"

Advanced Usage: Custom Templates

You can create custom templates that extend drunk-lib templates:

Environment-Specific Configurations

values-dev.yaml

global:
  tag: "dev"

deployment:
  replicaCount: 1

ingress:
  hosts:
    - host: "dev.myapp.example.com"

values-prod.yaml

global:
  tag: "v1.0.0"

deployment:
  replicaCount: 3

autoscaling:
  enabled: true
  minReplicas: 3
  maxReplicas: 10

ingress:
  hosts:
    - host: "myapp.example.com"
  tls:
    - secretName: "myapp-prod-tls"
      hosts:
        - "myapp.example.com"

Extending the Library

Adding New Templates

Create a new template file in templates/:
```
touch templates/_myresource.tpl
```
Define the named template: yamlapiVersion: v1 kind: MyResource metadata: name: labels: spec: # Your resource specification
Document the template in this README.

Template Best Practices

Naming: Use the drunk-lib. prefix for all templates
Conditionals: Always check if features are enabled before rendering
Defaults: Provide sensible defaults in values.yaml
Documentation: Document all configuration options
Testing: Add unit tests for new templates

Testing Templates

Use helm template to test template rendering:

# Test basic rendering
helm template test-release . --debug

# Test with custom values
helm template test-release . -f test-values.yaml --debug

# Test specific templates
helm template test-release . --show-only templates/deployment.yaml

Contributing

Development Setup

Clone the repository
Make changes to templates
Test with helm template
Update documentation
Submit a pull request

Template Guidelines

Follow existing naming conventions
Add comprehensive configuration options
Include proper error handling
Document all features
Test thoroughly

Versioning

The library follows semantic versioning:

Major: Breaking changes to template interfaces
Minor: New templates or non-breaking feature additions
Patch: Bug fixes and improvements

Changelog

v1.0.7

Added SecretProviderClass template for Azure Key Vault
Improved StatefulSet template
Enhanced volume mounting options

v1.0.6

Added HPA template
Improved resource management
Bug fixes in service template

Support

Issues: GitHub Issues
Documentation: Main Documentation
Author: Steven Hoang

This library is the foundation of the drunk-app chart and enables consistent, production-ready deployments across all applications.

drunk.charts

Drunk-lib Library Chart Reference

Table of Contents

Overview

Purpose

Key Benefits

Architecture

Library Chart Structure

Template Naming Convention

Available Templates

Core Resources

Configuration Resources

Storage Resources

Batch Resources

Scaling & Security

Template Reference

Helper Templates

app.name

app.fullname

app.labels

app.selectorLabels

Deployment Template

Key Features:

Configuration:

StatefulSet Template

Configuration:

Service Template

Configuration:

ConfigMap Template

Configuration:

Secrets Template

Configuration:

SecretProviderClass Template

Configuration:

CronJob Template

Configuration:

Job Template

Configuration:

Volumes Template

Configuration:

Ingress Template

Configuration:

HPA Template

Configuration:

NetworkPolicy Template

Legacy Single Policy Configuration:

Multiple Policies Configuration (Recommended):

Configuration Options:

Usage Examples

Creating a Chart that Uses drunk-lib

1. Chart.yaml

2. Template Usage

3. Values Configuration

Advanced Usage: Custom Templates

Environment-Specific Configurations

Extending the Library

Adding New Templates

Template Best Practices

Testing Templates

Contributing

Development Setup

Template Guidelines

Versioning

Changelog

v1.0.7

v1.0.6

Support

`app.name`

`app.fullname`

`app.labels`

`app.selectorLabels`