The Encyclopedia of Kubernetes clusters
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 can be deployed as a standalone platform or integrated with Cluster API, Karmada, Clusternet and other multi-cloud platforms
In the next, Clusterpedia will implemente the feature of automatically synchronizing resources within clusters managed by
Cluster API,Karmada,Clusternetand other multi-cloud platforms.
- Support for retrieving resources using
kubectl,client-goorcontroller-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.
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,v1beta1version to retrieve the Deployments resources in different clusters.Notes: The version of deployments is
v1beta1in Kubernetes 1.10 and it isv1in 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"
}
}- Use
Collection Resourceto retrieve different types of resources, such asDeployment,DaemonSet,StatefulSet.
$ kubectl get collectionresources
NAME RESOURCES
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- 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
- Based on Aggregated API, the entry portal for multi-cluster retrieval is the same as that of the the master cluster(IP:PORT)
- Optimized caches used by informer, so the memory usage is very low for resource synchronization.
- Automatic start/stop synchronization based on cluster health status
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
- Clusterpedia APIServer: Register to
Kubernetes APIServerby 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
| 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 |
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
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 ResourcesIt 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
...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 64dGet 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 41dGet 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 41dGet 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 41dUsage 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 68dExcept 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-dnsFind 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 7d21hUse 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
workloads deployments.apps,daemonsets.apps,statefulsets.appsBy 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 109dAdd 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.
The resource used to represent the cluster in Clusterpedia is called PediaCluster, not a simple Cluster.
This is because Clusterpedia was originally designed to build on the existing multi-cluster management platform.
In order to keep the original intention, the first issue is that Clusterpedia should not conflict with the resources in the existing multi-cluster platform. Cluster is a very common resource name that represents a cluster.
In addition, in order to better connect with the existing multi-cluster platform and enable the connected clusters automatically complete resource synchronization, we need a new mechanism to discover clusters. This discovery mechanism needs to solve the following issues:
- Get the authentication info to access the cluster
- Configure conditions that trigger the lifecycle of PediaCluster
- Set the default policy and prefix name for resource synchronization
This feature will be discussed and implemented in detail in Q1 or Q2 2022.
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
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.
If you have any question, feel free to reach out to us in the following ways:
Thanks go to these wonderful people (emoji key):
 Paco Xu |
 Shiming Zhang |
Copyright 2022 the Clusterpedia Authors. All rights reserved.
Licensed under the Apache License, Version 2.0.