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kubernetes simple multi-cluster solution

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Introduction

Project background: In the current cloud native architecture, there are often scenarios where "multiple clusters" need to be operated at the same time, whether it is multi-cluster "query" or "resource distribution" operations. This project uses informer + operator performs extended encapsulation, Implement multi-cluster and multi-resource solutions.

Supported functions:

  1. Support "multi-cluster" configuration
  2. Support "multi-resource" configuration
  3. Support skipping restconfig tls authentication
  4. Implement http server support query interface
  5. Support querying multi-cluster command line plug-ins (list, describe)
  6. Support multiple clusters to deliver resources
  7. Support multi-cluster differentiated configuration

Configuration file

  • Important The configuration file can refer to the configuration in config.yaml. here
  • The caller only needs to pay attention to the content in the configuration file.
clusters:                     # Cluster list
  - metadata:
      clusterName: tencent1   # Custom cluster name
      insecure: false         # Whether to enable skipping tls certificate authentication
      configPath: /Users/zhenyu.jiang/.kube/config # kubeconfig configuration file address
  - metadata:
      clusterName: tencent2
      insecure: true
      isMaster: true          # master cluster
      configPath: /Users/zhenyu.jiang/go/src/golanglearning/new_project/multi_resource/multiclusterresource/config1 # kube config 

Multi-cluster ctl query (also supports http server query)

Query for most k8s resources is currently supported. You need to enter the GVR of the resource object, such as: v1.pods or batch.v1.jobs or v1.apps.deployments

  • (Except for special resources, such as metrics.k8s.io authentication.k8s.io authorization.k8s.io, these groups are currently not supported)
  • The resource object of the core group supports input in two forms: core.v1.pods or v1.pods. Core can be written or not.

Suffix parameter:

  • --namespace:Query by namespace. If not filled in, all namespaces will be queried by default.
  • --clusterName:Query by cluster name. If not filled in, all clusters will be queried by default.
  • --name: Query by name, if not filled in, query all by default
➜  cmd git:(main) ✗ go run ctl_plugin/main.go list v1.configmaps --clusterName=tencent2      
集群名称          NAME                                   NAMESPACE               DATA 
tencent2        test-scheduling-config                  kube-system             1       
tencent2        loki-loki-stack-test                    loki-stack              1       
tencent2        kube-root-ca.crt                        loki-stack              1       
tencent2        loki-loki-stack                         loki-stack              1       
tencent2        kube-root-ca.crt                        etcd01                  1       
tencent2        kube-root-ca.crt                        mycsi                   1  

➜  cmd git:(main) ✗ go run ctl_plugin/main.go v1.configmaps --clusterName=tencent2 --name=coredns --namespace=kube-system       
集群名称        CONFIGMAP       NAMESPACE       DATA 
tencent2        coredns         kube-system     1       

Query multi-cluster pods resources

➜  cmd git:(main) ✗ go run ctl_plugin/main.go list core.v1.pods --clusterName=tencent2                                   
集群名称         NAME                                                    NAMESPACE               POD IP          状态             容器名                           容器静像                                                                        
tencent2        virtual-kubelet-pod-test-bash                           default                                 Running         ngx1                            nginx:1.18-alpine                                                                    
tencent2        testpod1                                                default                                 Running         mytest                          nginx:1.18-alpine                                                                    
tencent2        loki-promtail-zxpvg                                     loki-stack                              Running         promtail                        docker.io/grafana/promtail:2.7.4                                                     
tencent2        node-exporter-srqk4                                     prometheus                              Running         node-exporter                   bitnami/node-exporter:1.4.0                                                          
tencent2        node-exporter-m5whb                                     prometheus                              Running         node-exporter                   bitnami/node-exporter:1.4.0                                                          
tencent2        loki-promtail-fcpsb                                     loki-stack                              Running         promtail                        docker.io/grafana/promtail:2.7.4                                                     
tencent2        testpod                                                 default                                 Pending         mytest                          nginx:1.18-alpine                                                                    
tencent2        nginx-kubelet                                           default                                 Running         nginx                           nginx:1.18-alpine                                                                    
tencent2        dep-test-8b4fcc97-pzbqd                                 default                 10.244.0.124    Running         dep-test-container              nginx:1.18-alpine                                                                    
tencent2        dep-test-8b4fcc97-jkkx7                                 default                 10.244.0.127    Running         dep-test-container              nginx:1.18-alpine                                                                    
tencent2        dep-test-8b4fcc97-wl6td                                 default                 10.244.0.128    Running         dep-test-container              nginx:1.18-alpine                                               

# If clusterName is not specified, all clusters will be queried by default.
➜  multi_resource git:(main) ✗ go run cmd/ctl_plugin/main.go list core.v1.pods                           
集群名称         NAME                                                            NAMESPACE                               NODE                    POD IP          状态             容器名                        容器静像                                                                            
tencent1        patch-deployment-7877dfff-975bn                                 default                                 minikube                10.244.1.40     Running         nginx                        nginx:1.15.2                                                                            
tencent1        patch-deployment-7877dfff-dwpxj                                 default                                 minikube                10.244.1.39     Running         nginx                        nginx:1.15.2                                                                            
tencent2        virtual-kubelet-pod-test-bash                                   default                                 mynode                                  Running         ngx1                         nginx:1.18-alpine                                                                       
tencent1        kueue-controller-manager-56987d8f8c-69gr7                       kueue-system                            minikube                10.244.1.16     Running         manager                      registry.k8s.io/kueue/kueue:v0.4.1                                                      
tencent2        testpod1                                                        default                                 my-sample-kubelet                       Running         mytest                       nginx:1.18-alpine                                                                       
tencent2        loki-promtail-zxpvg                                             loki-stack                              my-sample-kubelet                       Running         promtail                     docker.io/grafana/promtail:2.7.4                                                        
tencent2        node-exporter-srqk4                                             prometheus                              my-sample-kubelet                       Running         node-exporter                bitnami/node-exporter:1.4.0                                                             
tencent2        node-exporter-m5whb                                             prometheus                              myk8s                                   Running         node-exporter                bitnami/node-exporter:1.4.0                                                             
tencent2        loki-promtail-fcpsb                                             loki-stack                              myk8s                                   Running         promtail                     docker.io/grafana/promtail:2.7.4                                                        
tencent2        testpod                                                         default                                 myjtthink                               Pending         mytest                       nginx:1.18-alpine                                                                       
tencent2        nginx-kubelet                                                   default                                 myjtthink                               Running         nginx                        nginx:1.18-alpine                                                                       
tencent2        dep-test-8b4fcc97-pzbqd                                         default                                 vm-0-16-centos          10.244.0.124    Running         dep-test-container           nginx:1.18-alpine                                                                       
tencent2        dep-test-8b4fcc97-jkkx7                                         default                                 vm-0-16-centos          10.244.0.127    Running         dep-test-container           nginx:1.18-alpine                                                                       
tencent2        dep-test-8b4fcc97-wl6td                                         default                                 vm-0-16-centos          10.244.0.128    Running         dep-test-container           nginx:1.18-alpine                                                                       
tencent2        dep-test-8b4fcc97-znlp5                                         default                                 vm-0-16-centos          10.244.0.125    Running         dep-test-container           nginx:1.18-alpine                                                                       
tencent2        dep-test-8b4fcc97-vxf55                                         default                                 vm-0-16-centos          10.244.0.126    Running         dep-test-container           nginx:1.18-alpine                                                                       
tencent2        inspect-script-task-task3--1-fjxm9                              default                                 vm-0-16-centos          10.244.0.94     Pending         default                      inspect-operator/script-engine:v1

Query multi-cluster deployments resources

➜  cmd git:(main) ✗ go run ctl_plugin/main.go list apps.v1.deployments --clusterName=cluster2
集群名称         NAME                                    NAMESPACE               TOTAL   AVAILABLE       READY 
tencent1        dep-test                                default                 5       5               5       
tencent1        testngx                                 default                 10      10              10      
tencent1        test-pod-maxnum-scheduler               kube-system             1       1               1       
tencent1        myingress-controller                    default                 1       1               1       
tencent1        myapi                                   default                 1       1               1       

Query multi-cluster pods resource details

➜  multi_resource git:(main) ✗ go run cmd/ctl_plugin/main.go describe core.v1.pods --clusterName=tencent2 --namespace=default --name=myredis-0
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: "2023-01-18T15:14:48Z"
  managedFields:
  - apiVersion: v1
...  

Deploy Ctl tool

➜  ctl_plugin git:(main) ✗ pwd
/xxxxx/multi_resource/cmd/ctl_plugin
➜  ctl_plugin git:(main) ✗ go build -o kubectl-multicluster .
➜  ctl_plugin git:(main) ✗ chmod 777 kubectl-multicluster                     
➜  ctl_plugin git:(main) ✗ mv kubectl-multicluster ~/go/bin/ 
➜  ~ kubectl-multicluster list pods --clusterName=tencent1 --name=multiclusterresource-deployment-75d98bb7bd-xj5z5
集群名称        NAME                                                    NAMESPACE       NODE            POD IP          状态    容器名                  容器镜像            
tencent1        multiclusterresource-deployment-75d98bb7bd-xj5z5        default         vm-0-12-centos  10.244.29.32    Running example-container       nginx:1.19.0-alpine   

Note: The default command line of this project will read the ~/.multi-cluster-operator/config configuration, which will be automatically created when the project starts. If there are related errors when using the command line, you can handle the relevant parts yourself.

➜  .multi-cluster-operator pwd
/Users/zhenyu.jiang/.multi-cluster-operator
➜  .multi-cluster-operator cat config                
server: 31888

Delivering resources to multiple clusters

Idea: The above configuration file will specify the main cluster (isMaster) field. The main cluster is used to deploy the operator controller. That is, only the main cluster in multiple clusters can deliver resources and delete resources, and other clusters can only passively receive them.

  • The crd resource object is as follows. For more information, please refer to Reference
    • template field: resource template, fill in the required k8s original resources internally
    • placement field: select the cluster to be distributed
    • customize field: differentiated configuration between clusters
apiVersion: mulitcluster.practice.com/v1alpha1
kind: MultiClusterResource
metadata:
  name: mypod.pod
  namespace: default
spec:
   # Resource template, fill in the required k8s original resources
   template:
     apiVersion: v1
     kind: Pod
     metadata:
       name: multicluster-pod
       namespace: default
     spec:
       containers:
         - image: busybox
           command:
             - sleep
             - "3600"
           imagePullPolicy: IfNotPresent
           name: busybox
       restartPolicy: Always
   # You can choose different clusters for delivery. If modified,
   # Resources for specific clusters will also be added or deleted accordingly.
   # Note: If placement is deleted, the corresponding cluster of customize also needs to be deleted! !
   placement:
     clusters:
       - name: tencent1
       - name: tencent2
       - name: tencent4
   # Can be blank
   # Differentiated configuration between multiple clusters
   customize:
     clusters:
       - name: tencent1
         action:
           # Replace image
           - path: "/spec/containers/0/image"
             op: "replace"
             value:
               - "nginx:1.19.0-alpine"
       - name: tencent2
         action:
           # add annotations
           - path: "/metadata/annotations/example"
             value:
               - "example"
             op: "add"
  • usage

It can be seen that after a CRD is created in the main cluster, it will be automatically distributed to other clusters.

# apply
➜  multi_resource git:(main) ✗ kubectl apply -f yaml/test.yaml    
multiclusterresource.mulitcluster.practice.com/mypod.pod created
# query
➜  multi_resource git:(main) ✗ kubectl get multiclusterresources.mulitcluster.practice.com    
NAME        AGE
mypod.pod   45m
➜  multi_resource git:(main) ✗ go run cmd/ctl_plugin/main.go list pods  --namespace=default --name=multicluster-pod
集群名称        NAME                    NAMESPACE       NODE            POD IP          状态    容器名  容器静像 
tencent4        multicluster-pod        default         vm-0-17-centos  10.244.167.193  Running busybox busybox         
tencent1        multicluster-pod        default         minikube        10.244.1.48     Running busybox busybox         
tencent2        multicluster-pod        default         vm-0-16-centos  10.244.0.142    Running busybox busybox   
# Use the customize field to achieve differentiated deployment
➜  cmd git:(main) ✗ go run ctl_plugin/main.go list deployments --name=multiclusterresource-deployment
集群名称        NAME                            NAMESPACE       TOTAL   AVAILABLE       READY 
tencent4        multiclusterresource-deployment default         3       3               3       
tencent1        multiclusterresource-deployment default         2       2               2       
tencent2        multiclusterresource-deployment default         1       1               1       

Deploy application

Note: The project depends on mysql. It is recommended to use the mariadb:10.5 image. The dependency configuration is set in the deploy.yaml args field. Note: Before deployment, you need to create the library and table corresponding to mysql. Please refer to the table structure. mysql tables

  1. docker image
[root@VM-0-16-centos multi_resource_operator]# docker build -t multi-cluster-operator:v1 .
Sending build context to Docker daemon  1.262MB
Step 1/17 : FROM golang:1.20.7-alpine3.17 as builder
 ---> 864c54ad9c0d
Step 2/17 : WORKDIR /app
 ---> Using cache
 ---> b1cd56e3903a
Step 3/17 : COPY go.mod go.mod
  1. Deploy application deployment
[root@VM-0-16-centos multi_resource_operator]# kubectl apply -f deploy/rbac.yaml
serviceaccount/multi-cluster-operator-sa unchanged
clusterrole.rbac.authorization.k8s.io/multi-cluster-operator-clusterrole unchanged
clusterrolebinding.rbac.authorization.k8s.io/multi-cluster-operator-ClusterRoleBinding unchanged
[root@VM-0-16-centos multi_resource_operator]# kubectl apply -f deploy/deploy.yaml
deployment.apps/multi-cluster-operator unchanged
service/multi-cluster-operator-svc unchanged
  1. use kubectl log or exec check project application
[root@VM-0-16-centos ~]# kubectl get pods | grep multi-cluster-operator
multi-cluster-operator-7c477d7b58-z4bbd            1/1     Running            0          10d
[root@VM-0-16-centos ~]# kubectl logs multi-cluster-operator-7c477d7b58-z4bbd
I0928 07:29:45.956381       1 init_ctl_config.go:37] multi-cluster-ctl config file created successfully.
I0928 07:29:46.045113       1 multi_cluster.go:117] [tencent1] informer watcher start..
I0928 07:29:46.045147       1 handler.go:27] worker queue start...
I0928 07:29:46.146385       1 multi_cluster.go:117] [tencent2] informer watcher start..
I0928 07:29:46.146407       1 handler.go:27] worker queue start...
I0928 07:29:46.252256       1 multi_cluster.go:117] [tencent4] informer watcher start..
I0928 07:29:46.252275       1 handler.go:27] worker queue start...
I0928 07:29:46.353115       1 main.go:85] operator manager start...
[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
  1. Check whether the command line configuration file exists
[root@VM-0-16-centos multi_resource_operator]# cd
[root@VM-0-16-centos ~]# cd .multi-cluster-operator/
[root@VM-0-16-centos .multi-cluster-operator]# pwd
/root/.multi-cluster-operator
[root@VM-0-16-centos .multi-cluster-operator]# cat config
server: 31888
[root@VM-0-16-centos .multi-cluster-operator]#