K8s Multicluster

Multi-Cluster Kubernetes Management

Cross-cluster operations and context management using kubectl-mcp-server's multi-cluster support.

When to Apply

Use this skill when:

• User mentions: "cluster", "context", "multi-cluster", "cross-cluster"
• Operations: switching contexts, comparing clusters, federated deployments
• Keywords: "different environment", "production vs staging", "all clusters"

Priority Rules

Quick Reference

Context Management

List Available Contexts

list_contexts_tool()

View Current Context

kubeconfig_view()

Switch Context

CLI: kubectl-mcp-server context <context-name>

Cross-Cluster Operations

All kubectl-mcp-server tools support the context parameter:

get_pods(namespace="default", context="production-cluster")

get_pods(namespace="default", context="staging-cluster")

Common Multi-Cluster Patterns

Compare Environments

compare_namespaces(
    namespace1="production",
    namespace2="staging",
    resource_type="deployment",
    context="production-cluster"
)

Parallel Queries

Query multiple clusters simultaneously:

get_pods(namespace="app", context="prod-us-east")
get_pods(namespace="app", context="prod-eu-west")

get_pods(namespace="app", context="development")

Cross-Cluster Health Check

for context in ["prod-1", "prod-2", "staging"]:
    get_nodes(context=context)
    get_pods(namespace="kube-system", context=context)

Cluster API (CAPI) Management

For managing cluster lifecycle:

List Managed Clusters

capi_clusters_list_tool(namespace="capi-system")

Get Cluster Details

capi_cluster_get_tool(name="prod-cluster", namespace="capi-system")

Get Workload Cluster Kubeconfig

capi_cluster_kubeconfig_tool(name="prod-cluster", namespace="capi-system")

Machine Management

capi_machines_list_tool(namespace="capi-system")
capi_machinedeployments_list_tool(namespace="capi-system")

Scale Cluster

capi_machinedeployment_scale_tool(
    name="prod-cluster-md-0",
    namespace="capi-system",
    replicas=5
)

See CONTEXT-SWITCHING.md for detailed patterns.

Multi-Cluster Helm

Deploy charts to specific clusters:

install_helm_chart(
    name="nginx",
    chart="bitnami/nginx",
    namespace="web",
    context="production-cluster"
)

list_helm_releases(
    namespace="web",
    context="staging-cluster"
)

Multi-Cluster GitOps

Flux Across Clusters

flux_kustomizations_list_tool(
    namespace="flux-system",
    context="cluster-1"
)

flux_reconcile_tool(
    kind="kustomization",
    name="apps",
    namespace="flux-system",
    context="cluster-2"
)

ArgoCD Across Clusters

argocd_apps_list_tool(namespace="argocd", context="management-cluster")

Federation Patterns

Secret Synchronization

get_secrets(namespace="app", context="source-cluster")

kubectl_apply(secret_manifest, namespace="app", context="target-cluster")

Cross-Cluster Service Discovery

With Cilium ClusterMesh or Istio multi-cluster:

cilium_nodes_list_tool(context="cluster-1")
istio_proxy_status_tool(context="cluster-2")

Best Practices

1. Naming Convention: Use descriptive context names (prod-us-east-1, staging-eu-west-1) 2. Access Control: Different kubeconfigs per environment 3. Always Specify Context: Avoid accidental cross-cluster operations 4. Cluster Groups: Organize by purpose (prod-*, staging-*, dev-*)

Related Skills

• k8s-troubleshoot - Debug across clusters
• k8s-gitops - GitOps multi-cluster
• k8s-capi - Cluster API management

Kubernetes Context Management

Patterns for managing multiple cluster contexts.

Understanding Contexts

A kubeconfig context combines:

• Cluster: API server URL and CA certificate
• User: Authentication credentials
• Namespace: Default namespace (optional)

Context Naming Conventions

By Environment

production-us-east-1
production-eu-west-1
staging-us-east-1
development

By Purpose

management-cluster
workload-cluster-1
workload-cluster-2
monitoring-cluster

By Team

team-a-dev
team-a-prod
team-b-dev
platform-admin

MCP Commands

# List all contexts
list_contexts_tool()

# View kubeconfig (sanitized)
kubeconfig_view()

Context in Every Command

All kubectl-mcp-server tools accept context parameter:

# Explicit context (recommended)
get_pods(namespace="default", context="production")
get_pods(namespace="default", context="staging")

# Current context (implicit)
get_pods(namespace="default")

Multi-Cluster Patterns

Compare Environments

# Get deployments from both clusters
prod_deps = get_deployments(namespace="app", context="production")
staging_deps = get_deployments(namespace="app", context="staging")

Cross-Cluster Secret Sync

# Read secret from source
secret = get_secrets(namespace="app", context="source-cluster")

# Apply to target (via manifest)
apply_manifest(secret_yaml, namespace="app", context="target-cluster")

Parallel Health Checks

contexts = ["prod-1", "prod-2", "staging"]
for ctx in contexts:
    nodes = get_nodes(context=ctx)
    pods = get_pods(namespace="kube-system", context=ctx)
    # Report status

Rolling Deployment Across Clusters

# Deploy to staging first
install_helm_chart(name="app", chart="./app",
                   namespace="prod", context="staging")

# Verify
get_pods(namespace="prod", label_selector="app=myapp", context="staging")

# Deploy to production regions sequentially
for region in ["us-east", "us-west", "eu-west"]:
    install_helm_chart(name="app", chart="./app",
                       namespace="prod", context=f"production-{region}")
    # Wait for healthy
    get_pods(namespace="prod", context=f"production-{region}")

Access Control Per Context

Separate Kubeconfigs

# Different files per environment
export KUBECONFIG=~/.kube/production.yaml
export KUBECONFIG=~/.kube/development.yaml

Service Account Per Cluster

# Different SAs for different access levels
# Production: read-only SA
get_pods(namespace="app", context="production-readonly")

# Development: full access SA
apply_manifest(manifest, namespace="app", context="development-admin")

Cluster API Management

For managing cluster lifecycle:

# List CAPI-managed clusters
capi_clusters_list_tool(namespace="capi-system")

# Get workload cluster kubeconfig
kubeconfig = capi_cluster_kubeconfig_tool(
    name="workload-cluster-1",
    namespace="capi-system"
)

# Use the kubeconfig to access workload cluster
# (save to file, add to contexts)

Federation Patterns

Kubefed Resources

Cross-cluster resource propagation with KubeFed.

Cluster Mesh (Cilium)

# Check Cilium cluster mesh status
cilium_nodes_list_tool(context="cluster-1")
cilium_nodes_list_tool(context="cluster-2")

Multi-Cluster Service Mesh (Istio)

istio_proxy_status_tool(context="primary")
istio_proxy_status_tool(context="remote")

Best Practices

1. Always Use Explicit Context

   # Good: explicit
   get_pods(context="production")

   # Risky: implicit
   get_pods()  # Which cluster?

2. Naming Convention

• Consistent format: <env>-<region>
• Short but descriptive

3. Read-Only for Production

• Default production context: read-only
• Separate admin context for changes

4. Audit Cross-Cluster Operations

• Log which clusters are accessed
• Track who made changes

5. Separate Credentials

• Different SAs per environment
• Shorter token lifetimes for prod

Troubleshooting

Context Not Found

list_contexts_tool()
# Verify context name is correct

Authentication Failure

# Check credentials
# Token expired?
# Certificate valid?

Network Issues

# API server reachable?
# VPN connected?
# Firewall rules?