Access the Clusterpedia

  4 minute read  

Clusterpedia has two main components:

  • ClusterSynchroManager manages the PediaCluster resource in the master cluster, connects to the specified cluster through the PediaCluster authentication information, and synchronizes the corresponding resources in real time.
  • APIServer also listens to the PediaCluster resource in the master cluster and provides complex search for resources in a compatible Kubernetes OpenAPI manner based on the resources synchronized by the cluster.
  • Controller Manager

Also, the Clusterpedia APIServer will be registered to the master cluster APIServer in the way of Aggregation API, so that we can access Clusterpedia through the same entry as the master cluster.

Resources and Collection Resource

Clusterpedia APIServer will provide two different resources to search under Group - clusterpedia.io:

kubectl api-resources | grep clusterpedia.io

# Output:
NAME                 SHORTNAMES    APIVERSION                 NAMESPACED   KIND
collectionresources                clusterpedia.io/v1beta1    false        CollectionResource
resources                          clusterpedia.io/v1beta1    false        Resources
  • Resources is used to specify a resource type to search for, compatible with Kubernetes OpenAPI
  • CollectionResource is used to search for new resource aggregated by different types to find multiple resource types at one time

For concepts and usage about Collection Resource, refer to What is Collection Resource and Search for Collection Resource.

Access the Clusterpedia resources

When searching for a resource of a specific type, you can request it according to the Get/List specification of Kubernetes OpenAPI. In this way we can not only use the URL to access Clusterpedia resources, but also directly use kubectl or client-go to search for the resources.

Clusterpedia uses URL Path to distinguish whether the request is a multi-cluster resource or a specific cluster:

Multi-cluster resource path, directly prefix the Resources path:

/apis/clusterpedia.io/v1beta1/resources

kubectl get --raw="/apis/clusterpedia.io/v1beta1/resources/version"

Specific cluster resource path, specify a cluster by setting the resource name based on the Resources path /apis/clusterpedia.io/v1beta1/resources/clusters/

kubectl get --raw="/apis/clusterpedia.io/v1beta1/resources/clusters/cluster-1/version"

Regardless of a resource path of multiple clusters or a specific cluster, the path can be spliced and followed by Kubernetes Get/List Path

Configure the cluster shortcut for kubectl

Although we can use URLs to access Clusterpedia resources, if we want to use kubectl to query more conveniently, we need to configure the kubeconfig cluster.

Clusterpedia provides a simple script to generate cluster config in the kubeconfig.

curl -sfL https://raw.githubusercontent.com/clusterpedia-io/clusterpedia/v0.7.0/hack/gen-clusterconfigs.sh | sh -

# Output:
Current Context: kubernetes-admin@kubernetes
Current Cluster: kubernetes
        Server: https://10.6.100.10:6443
        TLS Server Name:
        Insecure Skip TLS Verify:
        Certificate Authority:
        Certificate Authority Data: ***

Cluster "clusterpedia" set.
Cluster "cluster-1" set.
Cluster "cluster-2" set.

Check the script from hack/gen-clusterconfigs.sh

The script prints the current cluster information and configures the PediaCluster into kubeconfig.

cat ~/.kube/config

# .kube/config
- cluster:
    certificate-authority-data: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUMvakNDQWVhZ0F3SUJBZ0lCQURBTkJna3Foa2lHOXcwQkFRc0ZBREFWTVJNd0VRWURWUVFERXdwcmRXSmwKY201bGRHVnpNQjRYRFRJeE1Ea3lOREV3TVRNeU5Gb1hEVE14TURreU1qRXdNVE15TkZvd0ZURVRNQkVHQTFVRQpBeE1LYTNWaVpYSnVaWFJsY3pDQ0FTSXdEUVlKS29aSWh2Y05BUUVCQlFBRGdnRVBBRENDQVFvQ2dnRUJBTy9TCnZta1U5bk1uUlRIT3lvK3hjdFRJY0lPYnMzc0F5cTI2djRQYkVtb3ZWM2xPOVQwMTF2cE96S0pyOUFxeVZMRnYKVXFBRHBTakM3WXd3MnZwSld3bDEySlBvUm1xZ1FBSFNkYlJpU3BDTDRudjlvR25VOWI2dllWSy9iRitkUVFCSApnQ1h6NnZoTGY4Wmd2N2tUQ2JBdkFPaE9OSlU3MllYTE8zT0lZQjJva1NCRGFVUjNvNnpwZGVWTkt5V0EyNVA3CkRobk8yTk01QzlpRERqTTRLY2FTa3JPSkJvbUlsSHFZRjRwVXdTTlFvcGVGRVRyZ3ZzcTkwSks2YUJVS0t5ajYKK2NGdjI3S0k4K1ZMUEtaSTE2c25Mbng2RXRTazZtZjJXTHdJZlhyQlgwREsvYXBEQ015R2pEb2dCaGpJSVhoVAp2bjVQZndFWUNsdGZFTEhKSkdVQ0F3RUFBYU5aTUZjd0RnWURWUjBQQVFIL0JBUURBZ0trTUE4R0ExVWRFd0VCCi93UUZNQU1CQWY4d0hRWURWUjBPQkJZRUZJVDhLRHdCbUVvMHladUFEZkhkKzQ1L3ZFYzdNQlVHQTFVZEVRUU8KTUF5Q0NtdDFZbVZ5Ym1WMFpYTXdEUVlKS29aSWh2Y05BUUVMQlFBRGdnRUJBT0F5VHQ4S3ZFN0dvREhQT09pdgoyR2I2WWVsUU5KcUMza1dIOXc1NTFNaGZvS3ZiM21VaUV6ZVMwOUNwZUQrTFh5ZnlqQzhZYkJxQjZXSFhNZWMrCnpPdDNPazRYV0FmZVVZTXhOQ1FJblc4cjI4cmZnblErc1NCdHQyeERQN1RZY09oNVZGZkI2K3JtTmFTblZ1NjgKSFFxdlFMNEFXbVhkR09jRWNBRThYdkdiOWhwSjVNckRHdzQ0UTYyOG9YazZ0N01aWTFOMUNQdW9HZ1VmS1N3bgo1MUFWRTFOVVdNV0tEQXhaa2I4bEhvR3VWaDFzWmd3SnJRQjR5clh1cmxGN0Y2bVRlYm4rcDVKM0toT0V4KzlsCjFXdkwwbWkxL1J2bVJKNm11YmtjWUwzN1FJWjI1YXdyaEZMN0Z1ejNRSTFqTTdYMHZET2VUM2VuVUFCZW5SMS8KUnlnPQotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
    server: https://10.6.100.10:6443/apis/clusterpedia.io/v1beta1/resources/clusters/cluster-1
  name: cluster-1
- cluster:
    certificate-authority-data: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1JSUMvakNDQWVhZ0F3SUJBZ0lCQURBTkJna3Foa2lHOXcwQkFRc0ZBREFWTVJNd0VRWURWUVFERXdwcmRXSmwKY201bGRHVnpNQjRYRFRJeE1Ea3lOREV3TVRNeU5Gb1hEVE14TURreU1qRXdNVE15TkZvd0ZURVRNQkVHQTFVRQpBeE1LYTNWaVpYSnVaWFJsY3pDQ0FTSXdEUVlKS29aSWh2Y05BUUVCQlFBRGdnRVBBRENDQVFvQ2dnRUJBTy9TCnZta1U5bk1uUlRIT3lvK3hjdFRJY0lPYnMzc0F5cTI2djRQYkVtb3ZWM2xPOVQwMTF2cE96S0pyOUFxeVZMRnYKVXFBRHBTakM3WXd3MnZwSld3bDEySlBvUm1xZ1FBSFNkYlJpU3BDTDRudjlvR25VOWI2dllWSy9iRitkUVFCSApnQ1h6NnZoTGY4Wmd2N2tUQ2JBdkFPaE9OSlU3MllYTE8zT0lZQjJva1NCRGFVUjNvNnpwZGVWTkt5V0EyNVA3CkRobk8yTk01QzlpRERqTTRLY2FTa3JPSkJvbUlsSHFZRjRwVXdTTlFvcGVGRVRyZ3ZzcTkwSks2YUJVS0t5ajYKK2NGdjI3S0k4K1ZMUEtaSTE2c25Mbng2RXRTazZtZjJXTHdJZlhyQlgwREsvYXBEQ015R2pEb2dCaGpJSVhoVAp2bjVQZndFWUNsdGZFTEhKSkdVQ0F3RUFBYU5aTUZjd0RnWURWUjBQQVFIL0JBUURBZ0trTUE4R0ExVWRFd0VCCi93UUZNQU1CQWY4d0hRWURWUjBPQkJZRUZJVDhLRHdCbUVvMHladUFEZkhkKzQ1L3ZFYzdNQlVHQTFVZEVRUU8KTUF5Q0NtdDFZbVZ5Ym1WMFpYTXdEUVlKS29aSWh2Y05BUUVMQlFBRGdnRUJBT0F5VHQ4S3ZFN0dvREhQT09pdgoyR2I2WWVsUU5KcUMza1dIOXc1NTFNaGZvS3ZiM21VaUV6ZVMwOUNwZUQrTFh5ZnlqQzhZYkJxQjZXSFhNZWMrCnpPdDNPazRYV0FmZVVZTXhOQ1FJblc4cjI4cmZnblErc1NCdHQyeERQN1RZY09oNVZGZkI2K3JtTmFTblZ1NjgKSFFxdlFMNEFXbVhkR09jRWNBRThYdkdiOWhwSjVNckRHdzQ0UTYyOG9YazZ0N01aWTFOMUNQdW9HZ1VmS1N3bgo1MUFWRTFOVVdNV0tEQXhaa2I4bEhvR3VWaDFzWmd3SnJRQjR5clh1cmxGN0Y2bVRlYm4rcDVKM0toT0V4KzlsCjFXdkwwbWkxL1J2bVJKNm11YmtjWUwzN1FJWjI1YXdyaEZMN0Z1ejNRSTFqTTdYMHZET2VUM2VuVUFCZW5SMS8KUnlnPQotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
    server: https://10.6.100.10:6443/apis/clusterpedia.io/v1beta1/resources/clusters/cluster-2
  name: cluster-2
- cluster:
    certificate-authority-data: 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
    server: https://10.6.100.10:6443/apis/clusterpedia.io/v1beta1/resources
  name: clusterpedia
- cluster:
    certificate-authority-data: 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
    server: https://10.6.100.10:6443
  name: kubernetes

The script generates clusterpedia clusters for multi-cluster access and other cluster configs in the name of PediaCluster, and reuses the master cluster’s entry and authentication information when accessing Clusterpedia.

Compared with the master cluster entry, it only adds Clusterpedia Resources path.

After multi-cluster kubeconfig is generated, you can use kubectl --cluster to specify the cluster access

# Supported resources for multi-cluster search
kubectl --cluster clusterpedia api-resources

# Supported resources for cluster-1 search
kubectl --cluster cluster-1 api-resources

We can get the global and specific resource information according to the URL path.

Global resource information is the union of resource types that are synchronized across all clusters

Discovery API opened by Clusterpedia is similary compatible with Kubernetes OpenAPI. You can use kubectl, client-go/discovery, client-go/restmapper or controller-runtime/dynamic-restmapper to access it.

Use URL to get APIGroupList and APIGroup information

kubectl get --raw="/apis/clusterpedia.io/v1beta1/resources/apis" | jq

{
  "kind": "APIGroupList",
  "apiVersion": "v1",
  "groups": [
    {
      "name": "apps",
      "versions": [
        {
          "groupVersion": "apps/v1",
          "version": "v1"
        },
        {
          "groupVersion": "apps/v1beta2",
          "version": "v1beta2"
        },
        {
          "groupVersion": "apps/v1beta1",
          "version": "v1beta1"
        }
      ],
      "preferredVersion": {
        "groupVersion": "apps/v1",
        "version": "v1"
      }
    },
    {
      "name": "cert-manager.io",
      "versions": [
        {
          "groupVersion": "cert-manager.io/v1",
          "version": "v1"
        }
      ],
      "preferredVersion": {
        "groupVersion": "cert-manager.io/v1",
        "version": "v1"
      }
    }
  ]
}

kubectl get --raw="/apis/clusterpedia.io/v1beta1/resources/apis/apps" | jq

{
  "kind": "APIGroup",
  "apiVersion": "v1",
  "name": "apps",
  "versions": [
    {
      "groupVersion": "apps/v1",
      "version": "v1"
    },
    {
      "groupVersion": "apps/v1beta2",
      "version": "v1beta2"
    },
    {
      "groupVersion": "apps/v1beta1",
      "version": "v1beta1"
    }
  ],
  "preferredVersion": {
    "groupVersion": "apps/v1",
    "version": "v1"
  }
}

Use kubectl to get api-resources

kubectl --cluster clusterpedia api-resources

# Output:
NAME          SHORTNAMES   APIVERSION           NAMESPACED   KIND
configmaps    cm           v1                   true         ConfigMap
namespaces    ns           v1                   false        Namespace
nodes         no           v1                   false        Node
pods          po           v1                   true         Pod
secrets                    v1                   true         Secret
daemonsets    ds           apps/v1              true         DaemonSet
deployments   deploy       apps/v1              true         Deployment
replicasets   rs           apps/v1              true         ReplicaSet
issuers                    cert-manager.io/v1   true         Issuer