Add Helm Chart for MISP Kubernetes Deployment

[tobmes42]

Description

This PR adds a production-ready Helm chart for deploying MISP on Kubernetes with all required dependencies.

Features

Core Functionality

• Complete Helm chart with MariaDB and Valkey (Redis alternative) as dependencies
• Configurable deployment via values.yaml and example community-values.yaml
• Support for custom initialization scripts via ConfigMap
• Automatic secret generation for passwords and API keys

Security

• Security contexts with non-root containers
• Read-only root filesystems
• Network policies support
• Integration with Kubernetes Secrets
• Support for Vault secret management

Networking

• Ingress support with nginx-ingress-controller
• Automatic TLS certificate management via cert-manager
• Support for Istio service mesh (alternative to Ingress)
• Configurable service types (ClusterIP, NodePort, LoadBalancer)

Configuration

• OIDC/Keycloak authentication support
• Custom CA certificates mounting
• Environment variable configuration
• SOAR user creation
• Configurable resource limits and requests

Documentation

• Comprehensive deployment guide (DEPLOYMENT.md)
• Step-by-step installation instructions
• cert-manager setup guide
• Troubleshooting section
• Configuration examples

Prerequisites

• Kubernetes 1.19+
• Helm 3.0+
• Ingress Controller (e.g., nginx-ingress-controller)
• cert-manager for TLS certificate management
• StorageClass for persistent volumes

Testing

Tested on:

• ✅ OrbStack Kubernetes v1.33.5+orb1
• ✅ Local development environment
• ✅ nginx-ingress-controller v1.12.0-beta.0
• ✅ cert-manager v1.19.2

Installation Example

# 1. Install cert-manager
helm install cert-manager jetstack/cert-manager \
  --namespace cert-manager \
  --create-namespace \
  --set crds.enabled=true

# 2. Create ClusterIssuer
kubectl apply -f - <<EOF
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: selfsigned-issuer
spec:
  selfSigned: {}
EOF

# 3. Deploy MISP
helm upgrade --install misp ./kubernetes/helm-chart \
  -n misp \
  --create-namespace \
  -f ./kubernetes/helm-chart/community-values.yaml