KubeSphere Extension Management

---

Architecture

┌──────────────────────┐        ┌─────────────────────────────┐        ┌──────────────────────┐        ┌──────────────────────┐
│  Extension Museum    │        │  Extension                  │        │  InstallPlan         │        │  Deployed Extension  │
│  (Local Chart Repo)  │───────▶│  - description              │───────▶│  - extension         │───────▶│                      │
│                      │ (sync) │  - status                   │        │  - config            │        │  Namespace: <target> │
└──────────────────────┘        │  ExtensionVersion           │        │  - clusterScheduling │        │  └── Pods, Services   │
                                │  - version                  │        └──────────────────────┘        └──────────────────────┘
                                │  - chartURL                 │              │ (reconcile)
                                │  - externalDependencies     │              |
                                │  - installationMode         │              |
                                └─────────────────────────────┘              ▼
                                                                    ┌──────────────────────┐
                                                                    │  Job                 │
                                                                    │  helm-upgrade-<name> │
                                                                    │  - helm install/     │
                                                                    │    upgrade/uninstall │
                                                                    └──────────┬───────────┘
                                                                               │
                                                                               ▼
                                                                    ┌──────────────────────┐
                                                                    │  Pod                 │
                                                                    │  (Helm execution)    │
                                                                    └──────────────────────┘

Core Concepts

Extension

Metadata and status for available/installed extensions.

Field	Description	Example
metadata.name	Extension name	whizard-monitoring
spec.versions[]	Available versions	[1.2.0, 1.2.1]
status.state	Current state	Installed/Upgrading/Failed
status.enabled	Enabled status	true/false
status.installedVersion	Installed version	1.2.1

---

ExtensionVersion

Version-specific details: Helm chart location, dependencies, requirements.

Field	Description	Example
metadata.name	Version resource name	whizard-monitoring-1.2.1
spec.version	Version number	1.2.1
spec.chartURL	Helm chart URL	https://extensions-museum.../whizard-monitoring-1.2.1.tgz
spec.namespace	Target namespace	kubesphere-monitoring-system
spec.installationMode	Install mode	Multicluster/HostOnly
spec.ksVersion	Required KS version	>=4.2.0-0
spec.externalDependencies[]	Required extensions	[name: whizard-telemetry]

---

InstallPlan

Trigger for install/upgrade/uninstall. Creates Helm Job to deploy components.

Spec:

Field	Type	Required	Description
metadata.name	string	✅	Must match spec.extension.name
spec.extension.name	string	✅	Extension name
spec.extension.version	string	✅	Exact version to install
spec.enabled	bool	✅	Enable extension
spec.upgradeStrategy	string	✅	Use Manual for production
spec.config	string	❌	Custom YAML config
spec.clusterScheduling	object	❌	Multi-cluster config (Multicluster mode only)

Status:

Field	Description
status.state	Installed/Installing/Upgrading/Failed
status.jobName	Helm upgrade Job name
status.targetNamespace	Target namespace
status.conditions[]	Status conditions with messages

⚠️ CRITICAL:

• metadata.name = spec.extension.name
• Use EXACT version from user request
• Set enabled: true and upgradeStrategy: Manual

Step-by-Step Workflow

1. List and Inspect Extensions

# List all extensions
kubectl get extensions

# List by category
for c in $(kubectl get categories.kubesphere.io -o jsonpath='{.items[*].metadata.name}'); do
 exts=$(kubectl get extensions.kubesphere.io -l kubesphere.io/category="$c" -o jsonpath='{range .items[*]}{.metadata.name}{"\n"}{end}')
 [ -n "$exts" ] && echo -e "$c:\n$exts"
done

# List extension available versions
kubectl get extensionversions.kubesphere.io -l kubesphere.io/extension-ref=<extension-name>

# View extension details
kubectl describe extension <extension-name>
kubectl describe extensionversion.kubesphere.io <extension-name>-<version>

2. Install Extension

⚠️ CRITICAL:

• InstallPlan metadata.name MUST match spec.extension.name
• Use EXACT version from user request (not recommendedVersion or latest)

2.1 Verify Version Exists

# Verify the extension and version exist before creating InstallPlan
kubectl get extension <extension-name>
kubectl get extensionversion <extension-name>-<version>

# Get version details (check installationMode, namespace, dependencies, etc.)
kubectl describe extension <extension-name>
kubectl describe extensionversion <extension-name>-<version>

2.2 Create InstallPlan

Based on the extension details above:

• config: Omit if user didn't request custom configuration
• clusterScheduling: Only include if installationMode=Multicluster, specify clusters in placement.clusters

apiVersion: kubesphere.io/v1alpha1
kind: InstallPlan
metadata:
  name: <extension-name>
spec:
  # clusterScheduling:    # Only for Multicluster extensions.
  #   placement:
  #     clusters:
  #     - <cluster-name>
  #   overrides:
  #     host: |-
  #       # Extension agent configuration: custom settings for the extension agent in the current cluster, with higher priority than the global extension configuration.
  #
  #       custom:
  #         key: override-value
  # config: |  ## Omit if user didn't request custom config
  #   # Custom configuration for the extension, serving as a global extension configuration that can override default settings.
  #
  #   custom:
  #     key: override-value
  enabled: true
  extension:
    name: <extension-name>     # CRITICAL: MUST match metadata.name
    version: <version>         # CRITICAL: Use EXACT version requested
  upgradeStrategy: Manual

kubectl apply -f installplan-<extension-name>.yaml

3. Track & Verify Installation

# Watch status
kubectl get installplan <extension-name> -w

# Get details
kubectl describe installplan <extension-name>

# Verify extension status
kubectl describe extension <extension-name>

# Check deployed resources
NAMESPACE=$(kubectl get installplan <extension-name> -o jsonpath='{.status.targetNamespace}')
kubectl get pods,svc -n $NAMESPACE

4. Update & Upgrade Extension

⚠️ CRITICAL: InstallPlan metadata.name MUST match spec.extension.name

• Update: Modify spec.config or spec.clusterScheduling (version unchanged)
• Upgrade: Modify spec.extension.version to new version

# Get current InstallPlan as template
kubectl get installplan <extension-name> -o yaml > installplan-<extension-name>.yaml

# Edit and apply:
# - For Update: modify spec.config or spec.clusterScheduling
# - For Upgrade: change spec.extension.version to target version
kubectl apply -f installplan-<extension-name>.yaml
kubectl get installplan <extension-name> -w

5. Uninstall Extension

kubectl delete installplan <extension-name>

Best Practices

• Use default config (omit spec.config) unless custom values are needed
• Always use upgradeStrategy: Manual for production
• Use exact version (not recommendedVersion or latest)
• Test in staging before production
• Review changelogs before upgrades
• Document custom configurations

Troubleshooting

Issue 1: InstallPlan Failed (Job Execution Failed)

Symptoms: InstallPlan stuck in "Installing"/"Upgrading", Job pod shows Error/Failed

Diagnosis:

# Step 1: Check InstallPlan status
kubectl describe installplan <extension-name>
# Check status.state and status.conditions

# Step 2: Check Job pod logs
NAMESPACE=$(kubectl get installplan <extension-name> -o jsonpath='{.status.targetNamespace}')
JOB_NAME=$(kubectl get installplan <extension-name> -o jsonpath='{.status.jobName}')
kubectl logs -n $NAMESPACE -l job-name=$JOB_NAME --tail=100

# Step 3: For Multicluster - check cluster scheduling status
kubectl get installplan <extension-name> -o jsonpath='{.status.clusterSchedulingStatuses}' | jq .
# Check each cluster's state and conditions, then get job name and logs

Solutions:

• Verify extension version exists
• Check dependencies are installed
• Check config syntax

---

Issue 2: InstallPlan Status Not Updated (Job Completed)

Symptoms: Job pod completed successfully, but InstallPlan stays in "Installing"/"Upgrading"

Diagnosis:

# Check if job completed
NAMESPACE=$(kubectl get installplan <extension-name> -o jsonpath='{.status.targetNamespace}')
JOB_NAME=$(kubectl get installplan <extension-name> -o jsonpath='{.status.jobName}')
kubectl get pods -n $NAMESPACE -l job-name=$JOB_NAME

# Check job completion time vs current time
kubectl get job $JOB_NAME -n $NAMESPACE -o jsonpath='{.status.completionTime}'

Cause: Clock skew between nodes (NTP not synchronized)

Solution: Check and synchronize NTP across all cluster nodes

Quick Reference

Action	Command
List all extensions	kubectl get extensions
List extension versions	kubectl get extensionversions.kubesphere.io -l kubesphere.io/extension-ref=<name>
View extension details	kubectl describe extension <name>
View version details	kubectl describe extensionversion <name>-<version>
Install extension	kubectl apply -f installplan-<name>.yaml
Track installation	kubectl get installplan <name> -w
Upgrade extension	Modify version in InstallPlan, then kubectl apply
Uninstall extension	kubectl delete installplan <name>

References

• KubeSphere Extensions Documentation
• KubeSphere Extensions Marketplace

Related Skills

• kubesphere-core - Core platform architecture
• kubesphere-cluster-management - Cluster operations