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README

The Encyclopedia of Kubernetes clusters

Clusterpedia

This name Clusterpedia is inspired by Wikipedia. It is an encyclopedia of multi-cluster to synchronize, search for, and simply control multi-cluster resources.

Clusterpedia can synchronize resources with multiple clusters and provide more powerful search features on the basis of compatibility with Kubernetes OpenAPI to help you effectively get any multi-cluster resource that you are looking for in a quick and easy way.

The capability of Clusterpedia is not only to search for and view but also simply control resources in the future, just like Wikipedia that supports for editing entries.

Clusterpedia is a Cloud Native Computing Foundation sandbox project.

If you want to join the clusterpedia channel on CNCF slack, please get invite to CNCF slack and then join the #clusterpedia channel.

Why Clusterpedia

Clusterpedia can be deployed as a standalone platform or integrated with Cluster API, Karmada, Clusternet, vCluster, KubeVela and other multi-cloud platforms

Automatic synchronization of clusters managed by multi-cloud platforms

The clusterpedia can automatically synchronize the resources within the cluster managed by the multi-cloud platform.

Users do not need to maintain Clusterpedia manually, Clusterpedia can work as well as the internal components of the multi-cloud platforms.

Lean More About Interfacing to Multi-Cloud Platforms

More retrieval features and compatibility with Kubernetes OpenAPI

Support for retrieving resources using kubectl, client-go or controller-runtime/client, client-go example
The resource metadata can be retrived via API or client-go/metadata
Rich retrieval conditions: Filter by cluster/namespace/name/creation, Search by parent or ancestor owner,Multi-Cluster Label Selector, Enhanced Field Selector, Custom Search Conditions, etc.

Support for importing Kubernetes 1.10+

Automic conversion of different versions of Kube resources and support for multiple version of resources

Even if you import different version of Kube, we can still use the same resource version to retrieve resources

For example, we can use v1, v1beta2, v1beta1 version to retrieve the Deployments resources in different clusters.

>

Notes: The version of deployments is v1beta1 in Kubernetes 1.10 and it is v1 in Kubernetes 1.24.

$ 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"
  }
}

A single API can be used to retrieve different types of resources

Use Collection Resource to retrieve different types of resources, such as Deployment, DaemonSet, StatefulSet.

$ kubectl get collectionresources
NAME            RESOURCES
any             *
workloads       deployments.apps,daemonsets.apps,statefulsets.apps
kuberesources   .,.admission.k8s.io,.admissionregistration.k8s.io,.apiextensions.k8s.io,.apps,.authentication.k8s.io,.authorization.k8s.io,.autoscaling,.batch,.certificates.k8s.io,.coordination.k8s.io,.discovery.k8s.io,.events.k8s.io,.extensions,.flowcontrol.apiserver.k8s.io,.imagepolicy.k8s.io,.internal.apiserver.k8s.io,.networking.k8s.io,.node.k8s.io,.policy,.rbac.authorization.k8s.io,.scheduling.k8s.io,*.storage.k8s.io

Diverse policies and intelligent synchronization

Wildcards can be used to sync all types of resources within a specified group or cluster.
Support for synchronizing all custom resources
The type and version of resources that Clusterpedia is synchroizing with can be adapted to you CRD and AA changes

Unify the search entry for master clusters and multi-cluster resources

Based on Aggregated API, the entry portal for multi-cluster retrieval is the same as that of the master cluster(IP:PORT)

Very low memory usage and weak network optimization

Optimized caches used by informer, so the memory usage is very low for resource synchronization.
Automatic start/stop synchronization based on cluster health status

High availability

No dependency on specific storage components

Clusterpedia does not care about storage components and uses the storage layer to attach specific storage components, and will also add storage layers for graph databases and ES in the future

Architecture

The architecture consists of four parts:

Clusterpedia APIServer: Register to Kubernetes APIServer by the means of Aggregated API and provide services through a unified entrance
ClusterSynchro Manager: Manage the cluster synchro that is used to synchronize cluster resources
Storage Layer: Connect with a specific storage component and then register to Clusterpedia APIServer and ClusterSynchro Manager via a storage layer interface
Storage Component: A specific storage facility such as MySQL, PostgreSQL, Redis or other Graph Databases

In addition, Clusterpedia will use the Custom Resource - PediaCluster to implement cluster authentication and configure resources for synchronization.

Clusterpedia also provides a Default Storage Layer that can connect with MySQL and PostgreSQL.

Clusterpedia does not care about the specific storage components used by users,

you can choose or implement the storage layer according to your own needs,

and then register the storage layer in Clusterpedia as a plug-in

Installation | Import Clusters | Sync Cluster Resources

Search Label and URL Query

|Role| Search label key|URL query| | -- | --------------- | ------- | |Filter cluster names|search.clusterpedia.io/clusters|clusters| |Filter namespaces|search.clusterpedia.io/namespaces|namespaces| |Filter resource names|search.clusterpedia.io/names|names| |Fuzzy Search by resource name|internalstorage.clusterpedia.io/fuzzy-name|-| |Since creation time|search.clusterpedia.io/since|since| |Before creation time|search.clusterpedia.io/before|before| |Specified Owner UID|search.clusterpedia.io/owner-uid|ownerUID| |Specified Owner Seniority|search.clusterpedia.io/owner-seniority|ownerSeniority| |Specified Owner Name|search.clusterpedia.io/owner-name|ownerName| |Specified Owner Group Resource|search.clusterpedia.io/owner-gr|ownerGR| |Order by fields|search.clusterpedia.io/orderby|orderby| |Set page size|search.clusterpedia.io/size|limit| |Set page offset|search.clusterpedia.io/offset|continue| |Response include Continue|search.clusterpedia.io/with-continue|withContinue |Response include remaining count|search.clusterpedia.io/with-remaining-count|withRemainingCount |Custom Where SQL|-|whereSQL| |Get only the metadata of the collection resource | - |onlyMetadata | |Specify the groups of any collectionresource | - | groups | |Specify the resources of any collectionresource | - | resources |

Both Search Labels and URL Query support same operators as Label Selector:

exist, not exist
=, ==, !=
in, notin

More information about Search Conditions, Label Selector and Field Selector

Usage Samples

You can search for resources configured in PediaCluster, Clusterpedia supports two types of resource search:

Resources that are compatible with Kubernetes OpenAPI
Collection Resource

$ kubectl api-resources | grep clusterpedia.io
collectionresources     clusterpedia.io/v1beta1  false   CollectionResource
resources               clusterpedia.io/v1beta1  false   Resources

Use a compatible way with Kubernetes OpenAPI

It is possible to search resources via URL, but using kubectl may be more convenient if you configured the cluster shortcuts for kubectl.

We can use kubectl --cluster <cluster name> to specify the cluster, if <cluster name> is clusterpedia, it meas it is a multi-cluster search operation.

First check which resources are synchronized. We cannot find a resource until it is properly synchronized:

$ kubectl --cluster clusterpedia api-resources NAME SHORTNAMES APIVERSION NAMESPACED KIND configmaps cm v1 true ConfigMap events ev v1 true Event namespaces ns v1 false Namespace nodes no v1 false Node pods po v1 true Pod services svc v1 true Service daemonsets ds apps/v1 true DaemonSet deployments deploy apps/v1 true Deployment replicasets rs apps/v1 true ReplicaSet statefulsets sts apps/v1 true StatefulSet cronjobs cj batch/v1 true CronJob jobs batch/v1 true Job clusters cluster.kpanda.io/v1alpha1 false Cluster ingressclasses networking.k8s.io/v1 false IngressClass ingresses ing networking.k8s.io/v1 true Ingress clusterrolebindings rbac.authorization.k8s.io/v1 false ClusterRoleBinding clusterroles rbac.authorization.k8s.io/v1 false ClusterRole roles rbac.authorization.k8s.io/v1 true Role

$ kubectl --cluster cluster-1 api-resources ...

Search in Multiple Clusters

Usage of multi-cluster search in documents

Get deployments in the kube-system namespace of all clusters:

$ kubectl --cluster clusterpedia get deployments -n kube-system CLUSTER     NAME                      READY   UP-TO-DATE   AVAILABLE   AGE cluster-1   coredns                   2/2     2            2           68d cluster-2   calico-kube-controllers   1/1     1            1           64d cluster-2   coredns                   2/2     2            2           64d

Get deployments in the two namespaces kube-system and default of all clusters:

$ kubectl --cluster clusterpedia get deployments -A -l "search.clusterpedia.io/namespaces in (kube-system, default)" NAMESPACE     CLUSTER     NAME                      READY   UP-TO-DATE   AVAILABLE   AGE kube-system   cluster-1   coredns                   2/2     2            2           68d kube-system   cluster-2   calico-kube-controllers   1/1     1            1           64d kube-system   cluster-2   coredns                   2/2     2            2           64d default       cluster-2   dd-airflow-scheduler      0/1     1            0           54d default       cluster-2   dd-airflow-web            0/1     1            0           54d default       cluster-2   hello-world-server        1/1     1            1           27d default       cluster-2   openldap                  1/1     1            1           41d default       cluster-2   phpldapadmin              1/1     1            1           41d

Get deployments in the kube-system and default namespaces in cluster-1 and cluster-2:

$ kubectl --cluster clusterpedia get deployments -A -l "search.clusterpedia.io/clusters in (cluster-1, cluster-2),\      search.clusterpedia.io/namespaces in (kube-system,default)" NAMESPACE     CLUSTER     NAME                      READY   UP-TO-DATE   AVAILABLE   AGE kube-system   cluster-1   coredns                   2/2     2            2           68d kube-system   cluster-2   calico-kube-controllers   1/1     1            1           64d kube-system   cluster-2   coredns                   2/2     2            2           64d default       cluster-2   dd-airflow-scheduler      0/1     1            0           54d default       cluster-2   dd-airflow-web            0/1     1            0           54d default       cluster-2   hello-world-server        1/1     1            1           27d default       cluster-2   openldap                  1/1     1            1           41d default       cluster-2   phpldapadmin              1/1     1            1           41d

Get deployments in the kube-system and default namespaces in cluster-1 and cluster-2:

$ kubectl --cluster clusterpedia get deployments -A -l "search.clusterpedia.io/clusters in (cluster-1, cluster-2),\     search.clusterpedia.io/namespaces in (kube-system,default),\     search.clusterpedia.io/orderby=name" NAMESPACE     CLUSTER     NAME                      READY   UP-TO-DATE   AVAILABLE   AGE kube-system   cluster-2   calico-kube-controllers   1/1     1            1           64d kube-system   cluster-1   coredns                   2/2     2            2           68d kube-system   cluster-2   coredns                   2/2     2            2           64d default       cluster-2   dd-airflow-scheduler      0/1     1            0           54d default       cluster-2   dd-airflow-web            0/1     1            0           54d default       cluster-2   hello-world-server        1/1     1            1           27d default       cluster-2   openldap                  1/1     1            1           41d default       cluster-2   phpldapadmin              1/1     1            1           41d

Search a specific cluster

Usage of specified cluster search in documents

If you want to search a specific cluster for any resource therein, you can add --cluster to specify the cluster name:

$ kubectl --cluster cluster-1 get deployments -A NAMESPACE                           CLUSTER     NAME                                            READY   UP-TO-DATE   AVAILABLE   AGE calico-apiserver                    cluster-1   calico-apiserver                                1/1     1            1           68d calico-system                       cluster-1   calico-kube-controllers                         1/1     1            1           68d calico-system                       cluster-1   calico-typha                                    1/1     1            1           68d capi-system                         cluster-1   capi-controller-manager                         1/1     1            1           42d capi-kubeadm-bootstrap-system       cluster-1   capi-kubeadm-bootstrap-controller-manager       1/1     1            1           42d capi-kubeadm-control-plane-system   cluster-1   capi-kubeadm-control-plane-controller-manager   1/1     1            1           42d capv-system                         cluster-1   capv-controller-manager                         1/1     1            1           42d cert-manager                        cluster-1   cert-manager                                    1/1     1            1           42d cert-manager                        cluster-1   cert-manager-cainjector                         1/1     1            1           42d cert-manager                        cluster-1   cert-manager-webhook                            1/1     1            1           42d clusterpedia-system                 cluster-1   clusterpedia-apiserver                          1/1     1            1           27m clusterpedia-system                 cluster-1   clusterpedia-clustersynchro-manager             1/1     1            1           27m clusterpedia-system                 cluster-1   clusterpedia-internalstorage-mysql              1/1     1            1           29m kube-system                         cluster-1   coredns                                         2/2     2            2           68d tigera-operator                     cluster-1   tigera-operator                                 1/1     1            1           68d

Except for search.clusterpedia.io/clusters, the support for other complex queries is same as that for multi-cluster search.

If you want to learn about the details of a resource, you need to specify which cluster it is:

$ kubectl --cluster cluster-1 -n kube-system get deployments coredns -o wide CLUSTER     NAME      READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                   SELECTOR cluster-1   coredns   2/2     2            2           68d   coredns      registry.aliyuncs.com/google_containers/coredns:v1.8.4   k8s-app=kube-dns

Find the related pods by the name of the deployment

First view the deployments in default namespace

$ kubectl --cluster cluster-1 get deployments NAME                      READY   UP-TO-DATE   AVAILABLE   AGE fake-pod                  3/3     3            3           104d test-controller-manager   0/0     0            0           7d21h

Use owner-name to specify Owner Name and use owner-seniority to promote the Owner's seniority.

$ kubectl --cluster cluster-1 get pods -l "search.clusterpedia.io/owner-name=fake-pod,search.clusterpedia.io/owner-seniority=1"  NAME                                                 READY   STATUS      RESTARTS         AGE fake-pod-698dfbbd5b-74cjx                            1/1     Running     0                12d fake-pod-698dfbbd5b-tmcw7                            1/1     Running     0                3s fake-pod-698dfbbd5b-wvtvw                            1/1     Running     0                3s

Lean More About Search by Parent or Ancestor Owner

Search for Collection Resource

Clusterpedia can also perform more advanced aggregation of resources. For example, you can use Collection Resource to get a set of different resources at once.

Let's first check which Collection Resource currently Clusterpedia supports:

$ kubectl get collectionresources NAME        RESOURCES any             * workloads       deployments.apps,daemonsets.apps,statefulsets.apps kuberesources   .,.admission.k8s.io,.admissionregistration.k8s.io,.apiextensions.k8s.io,.apps,.authentication.k8s.io,.authorization.k8s.io,.autoscaling,.batch,.certificates.k8s.io,.coordination.k8s.io,.discovery.k8s.io,.events.k8s.io,.extensions,.flowcontrol.apiserver.k8s.io,.imagepolicy.k8s.io,.internal.apiserver.k8s.io,.networking.k8s.io,.node.k8s.io,.policy,.rbac.authorization.k8s.io,.scheduling.k8s.io,*.storage.k8s.io

By getting workloads, you can get a set of resources aggregated by deployments, daemonsets, and statefulsets, and Collection Resource also supports for all complex queries.

kubectl get collectionresources workloads will get the corresponding resources of all namespaces in all clusters by default:

$ kubectl get collectionresources workloads CLUSTER     GROUP   VERSION   KIND         NAMESPACE                     NAME                                          AGE cluster-1   apps    v1        DaemonSet    kube-system                   vsphere-cloud-controller-manager              63d cluster-2   apps    v1        Deployment   kube-system                   calico-kube-controllers                       109d cluster-2   apps    v1        Deployment   kube-system                   coredns-coredns                               109d

Add the collection of Daemonset in cluster-1 and some of the above output is cut out

Due to the limitation of kubectl, you cannot use complex queries in kubectl and can only be queried by URL Query.

Lean More

Proposals

Perform more complex control over resources

In addition to resource search, similar to Wikipedia, Clusterpedia should also have simple capability of resource control, such as watch, create, delete, update, and more.

In fact, a write action is implemented by double write + warning response.

We will discuss this feature and decide whether we should implement it according to the community needs

Notes

Multi-cluster network connectivity

Clusterpedia does not actually solve the problem of network connectivity in a multi-cluster environment. You can use tools such as tower to connect and access sub-clusters, or use submariner or skupper to solve cross-cluster network problems.