interLink Helm Chart

The official Helm chart for deploying interLink virtual nodes in Kubernetes clusters. interLink enables hybrid cloud deployments by creating virtual nodes that can execute workloads on remote computing resources while appearing as regular nodes to the Kubernetes scheduler.

Table of Contents

• Prerequisites
• Installation
• Deployment Modes
• Configuration
• Examples
• Post-Installation
• Troubleshooting
• Development

Prerequisites

• Kubernetes cluster (v1.20+)
• Helm 3.8+
• Appropriate RBAC permissions for virtual node operations
• For REST mode: OAuth2 provider configured
• For socket mode: SSH access to remote resources

Installation

From OCI Registry (Recommended)

# Add the repository
# Will be available once published:
# helm repo add interlink https://intertwin-eu.github.io/interlink-helm-chart/

# Update repositories
helm repo update

# Install with custom values
helm install --create-namespace -n interlink virtual-node \
  interlink/interlink --values my-values.yaml

From OCI Registry (Alternative)

helm install --create-namespace -n interlink virtual-node \
  oci://ghcr.io/intertwin-eu/interlink-helm-chart/interlink \
  --values my-values.yaml

Local Development

git clone https://github.com/interTwin-eu/interlink-helm-chart.git
cd interlink-helm-chart
helm install --create-namespace -n interlink virtual-node \
  ./interlink --values my-values.yaml

Deployment Modes

1. Edge-node Service (REST Communication)

Architecture: Virtual kubelet + OAuth2 token refresher in cluster, plugin + interLink API server + OAuth2 proxy on remote side.

Use Case: Secure communication over HTTPS with OAuth2 authentication.

# values-rest.yaml
nodeName: interlink-rest-node

interlink:
  address: https://your-remote-endpoint.com
  port: 443

OAUTH:
  enabled: true
  TokenURL: "https://your-oauth-provider.com/token"
  ClientID: "your-client-id"
  ClientSecret: "your-client-secret"
  RefreshToken: "your-refresh-token"
  Audience: "your-audience"

virtualNode:
  resources:
    CPUs: 16
    memGiB: 64
    pods: 200

2. Edge-node with Socket (SSH Communication)

Architecture: interLink + virtual kubelet + SSH bastion in cluster, only plugin on remote side.

Use Case: Secure communication via SSH tunnels using Unix sockets.

# values-socket.yaml
nodeName: interlink-socket-node

interlink:
  enabled: true
  socket: unix:///var/run/interlink.sock

plugin:
  socket: unix:///var/run/plugin.sock

sshBastion:
  enabled: true
  clientKeys:
    authorizedKeys: "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAI..."
  port: 31022

virtualNode:
  resources:
    CPUs: 8
    memGiB: 32
    pods: 100

3. In-cluster Mode

Architecture: All components (virtual kubelet, interLink, plugin) deployed in cluster with socket communication.

Use Case: Testing, development, or when remote resources support direct API access.

# values-incluster.yaml
nodeName: interlink-incluster-node

interlink:
  enabled: true
  socket: unix:///var/run/interlink.sock

plugin:
  enabled: true
  image: "ghcr.io/intertwin-eu/interlink/plugin-docker:latest"
  socket: unix:///var/run/plugin.sock
  config: |
    InterlinkURL: "unix:///var/run/interlink.sock"
    SidecarURL: "unix:///var/run/plugin.sock"
    VerboseLogging: true

virtualNode:
  resources:
    CPUs: 4
    memGiB: 16
    pods: 50

Configuration

Core Values

Parameter	Description	Default
nodeName	Name of the virtual node	virtual-node
virtualNode.image	Virtual kubelet image	ghcr.io/interlink-hq/interlink/virtual-kubelet-inttw:latest
virtualNode.resources.CPUs	Node CPU capacity	8
virtualNode.resources.memGiB	Node memory capacity in GiB	49
virtualNode.resources.pods	Maximum pods per node	100
interlink.enabled	Deploy interLink API server	false
plugin.enabled	Deploy plugin component	false

Advanced Configuration

Accelerators Support

virtualNode:
  resources:
    accelerators:
    - resourceType: nvidia.com/gpu
      model: a100
      available: 2
    - resourceType: xilinx.com/fpga
      model: u55c
      available: 1

Node Labels and Taints

virtualNode:
  nodeLabels:
    - "node-type=virtual"
    - "accelerator=gpu"
  nodeTaints:
    - key: "virtual-node"
      value: "true"
      effect: "NoSchedule"

Examples

Complete examples are available in the examples/ directory:

• edge_with_rest.yaml - REST communication setup
• edge_with_socket.yaml - Socket communication setup

Post-Installation

Verify Deployment

# Check virtual node status
kubectl get node <nodeName>

# Check pod status
kubectl get pods -n interlink

# View virtual node details
kubectl describe node <nodeName>

# Check logs
kubectl logs -n interlink deployment/<nodeName>-node -c vk

Testing the Virtual Node

# test-pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: test-workload
spec:
  nodeSelector:
    kubernetes.io/hostname: <nodeName>
  containers:
  - name: test
    image: busybox
    command: ["sleep", "3600"]

kubectl apply -f test-pod.yaml
kubectl get pod test-workload -o wide

Troubleshooting

Common Issues

Virtual Node Not Ready

# Check node conditions
kubectl describe node <nodeName>

# Check virtual kubelet logs
kubectl logs -n interlink deployment/<nodeName>-node -c vk

# Verify interLink connectivity
kubectl logs -n interlink deployment/<nodeName>-node -c interlink

Pod Scheduling Issues

# Check node resources
kubectl describe node <nodeName>

# Verify taints and tolerations
kubectl get node <nodeName> -o yaml | grep -A5 taints

# Check scheduler logs
kubectl logs -n kube-system deployment/kube-scheduler

Authentication Problems (REST mode)

# Check OAuth token refresh
kubectl logs -n interlink deployment/<nodeName>-node -c refresh-token

# Verify token file
kubectl exec -n interlink deployment/<nodeName>-node -c vk -- cat /opt/interlink/token

SSH Connection Issues (Socket mode)

# Check SSH bastion logs
kubectl logs -n interlink deployment/<nodeName>-node -c ssh-bastion

# Test SSH connectivity
kubectl exec -n interlink deployment/<nodeName>-node -c ssh-bastion -- ssh -T interlink@remote-host

Debug Mode

Enable verbose logging:

virtualNode:
  debug: true

Health Checks

The chart includes readiness and liveness probes. Check their status:

kubectl get pods -n interlink -o wide
kubectl describe pod <pod-name> -n interlink

Development

Chart Development

# Lint the chart
helm lint interlink/

# Template and preview
helm template virtual-node ./interlink --values examples/edge_with_socket.yaml

# Test installation
helm install --dry-run --debug virtual-node ./interlink --values my-values.yaml

Chart Versioning

This chart uses chartpress for automated versioning:

# Update version and publish
chartpress --push

# Reset to development
chartpress --reset

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly
5. Submit a pull request

For detailed contribution guidelines, see CONTRIBUTING.md.

Resources

• interLink Documentation
• Official Cookbook
• GitHub Repository
• Chart Repository (GitHub Pages coming soon)

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.