We can all agree that containerization technology has been highly adopted in the past decade. This is due to the fact that almost all organizations around the world have decided to modernize their existing applications for cloud use. Containerization is the packaging software code with all the required dependencies in a lightweight executable. Containers can be run using tools like docker, Podman, Kubernetes e.t.c
Kubernetes(k8s) is a free and open-source container orchestration tool that works by distributing the workload across a cluster of hosts. It also automates the container networking needs, storage, and persistent volumes while maintaining the desired container state.
When a Kubernetes environment grows, it can be hard to manage. This creates a high need for Kubernetes management tools. The available tools in the market include K9s, Weave scope, Dashboard + Kubectl + Kubeadm, KubeSpray, Kontena Lens, WKSctl, Rancher, Portainer, Headlamp, Konstellate e.t.c
KubeSphere is a distributed operating system that has a commitment to providing a plug-and-play architecture for cloud-native application management with Kubernetes as its kernel. This multi-tenant enterprise-grade platform has full-stack automated IT operations and streamlined DevOps workflows. It has a user-friendly web UI to help users build robust and feature-rich platforms. It also makes common functions such as resource management, DevOps (CI/CD), monitoring, logging, service mesh, multi-tenancy, auditing, alerting and notification, application lifecycle management, multi-cluster deployment, access control, storage and networking, autoscaling, registry management, and security management more effortless.
One of the fantastic features is that it allows third-party applications to integrate seamlessly into its ecosystem. Other features include:
- Open Source: with its open-source model, developments can be easily enhanced. Its source code is available on GitHub
- O&M Friendly: It hides the details of underlying infrastructure and helps modernize migrate, deploy and manage existing deployments
- Run KubeSphere Everywhere: this lightweight platform is more friendly to different cloud ecosystems. It can be installed on cloud platforms such as Alibaba Cloud, QingCloud, Tencent Cloud, AWS, Huawei Cloud e.t.c
- Landscape: KubeSphere is a member of the Kubernetes Conformance Certified platform and enriches the CNCF CLOUD NATIVE Landscape.
Today, we will learn how to install and use KubeSphere on an existing Kubernetes cluster.
Prerequisites
For this guide to work best, you need to have the following:
- CPU: 1 Core and above,
- Memory: 2 GB and above
- Kubernetes Version: 1.20.x, 1.21.x, 1.22.x, 1.23.x (experimental). This can be achieved using any of the guides below:
- Deploy HA Kubernetes Cluster on Rocky Linux 8 using RKE2
- Run Kubernetes on Debian with Minikube
- Deploy Kubernetes Cluster on Linux With k0s
- Install Kubernetes Cluster on Ubuntu using K3s
- Install Kubernetes Cluster on Rocky Linux 8 with Kubeadm & CRI-O
- Deploy k0s Kubernetes on Rocky Linux 9 using k0sctl
- Install Minikube Rocky Linux 9 and Create Kubernetes Cluster
Also, ensure that kubectl is installed.
curl -LO "https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl"
chmod +x kubectl
sudo mv kubectl /usr/local/bin
To be able to use the tool, export the admin config:
##For RKE2
export PATH=$PATH:/var/lib/rancher/rke2/bin export KUBECONFIG=/etc/rancher/rke2/rke2.yaml
##For K0s
export KUBECONFIG=/var/lib/k0s/pki/admin.confCheck the available nodes in the cluster
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready control-plane 3m38s v1.25.2+k0s
worker1 Ready <none> 100s v1.25.2+k0s
worker2 Ready <none> 92s v1.25.2+k0sStep 1 – Create Persistent Volumes For KubeSphere
One of the requirements of KubeSphere is to have a persistent volume set-up. We need to create a storage class in the cluster and set it as the default storage class.
Refer to our articles below on how to configure persistent storage for your Kubernetes cluster:
- Configure NFS as Kubernetes Persistent Volume Storage
- Dynamic hostPath PV Creation in Kubernetes using Local Path Provisioner
- How To Deploy Rook Ceph Storage on Kubernetes Cluster
- Deploy and Manage MinIO Storage on Kubernetes
Check if you have storage class configured and working.
$ kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
local-path (default) rancher.io/local-path Delete WaitForFirstConsumer false 13m
$ kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
kubesphere-sc (default) kubernetes.io/no-provisioner Delete WaitForFirstConsumer false 2m31s
Once the configurations have been made accordingly, apply the manifest.
kubectl create -f Kubevious-pv.ymlStep 2 – Deploy KubeSphere on Kubernetes
Once the cluster meets all the requirements, you can install KubeSphere. In this guide, we will use kubectl to install KubeSphere with the default minimal package.
Download installation manifest files.
VER=$( curl --silent "https://api.github.com/repos/kubesphere/ks-installer/releases/latest"| grep '"tag_name"'|sed -E 's/.*"([^"]+)".*/\1/')
wget https://github.com/kubesphere/ks-installer/releases/download/$VER/kubesphere-installer.yaml
wget https://github.com/kubesphere/ks-installer/releases/download/$VER/cluster-configuration.yamlApply to create kubernetes objects:
$ kubectl apply -f kubesphere-installer.yaml
customresourcedefinition.apiextensions.k8s.io/clusterconfigurations.installer.kubesphere.io created
namespace/kubesphere-system created
serviceaccount/ks-installer created
clusterrole.rbac.authorization.k8s.io/ks-installer created
clusterrolebinding.rbac.authorization.k8s.io/ks-installer created
deployment.apps/ks-installer created
$ kubectl apply -f cluster-configuration.yaml
clusterconfiguration.installer.kubesphere.io/ks-installer created
After running the two commands, you will have a namespace kubesphere-system created and several other resources started. You can follow through the deployment with the command:
kubectl logs -n kubesphere-system $(kubectl get pod -n kubesphere-system -l 'app in (ks-install, ks-installer)' -o jsonpath='{.items[0].metadata.name}') -fSample Output:
....
TASK [ks-core/prepare : KubeSphere | Getting installation init files] **********
changed: [localhost] => (item=ks-init)
TASK [ks-core/prepare : KubeSphere | Initing KubeSphere] ***********************
changed: [localhost] => (item=role-templates.yaml)
TASK [ks-core/prepare : KubeSphere | Generating kubeconfig-admin] **************
skipping: [localhost]
PLAY RECAP *********************************************************************
localhost : ok=29 changed=21 unreachable=0 failed=0 skipped=16 rescued=0 ignored=0
Start installing monitoring
Start installing multicluster
Start installing openpitrix
Start installing network
**************************************************
Waiting for all tasks to be completed ...
task network status is successful (1/4)
task openpitrix status is successful (2/4)
task multicluster status is successful (3/4)
....Check if all pods are running:
kubectl get pod --all-namespacesSample Output:
You can verify the status of the created PVs:
$ kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
kubesphere-pv 20Gi RWO Retain Bound kubesphere-monitoring-system/prometheus-k8s-db-prometheus-k8s-0 kubesphere-sc 27m
kubesphere-pv2 20Gi RWO Retain Bound kubesphere-monitoring-system/prometheus-k8s-db-prometheus-k8s-1 kubesphere-sc 15mFrom the output, the two PVs have been bound. This means that they are under use. You can also view PVCs created:
$ kubectl get pvc -A
NAMESPACE NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
kubesphere-monitoring-system prometheus-k8s-db-prometheus-k8s-0 Bound kubesphere-pv 20Gi RWO kubesphere-sc 26m
kubesphere-monitoring-system prometheus-k8s-db-prometheus-k8s-1 Bound kubesphere-pv2 20Gi RWO kubesphere-sc 25mNow we can proceed and get the port for the ks-console. The default port is 30880
$ kubectl get svc/ks-console -n kubesphere-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ks-console NodePort 10.110.224.204 <none> 80:30880/TCP 30mWe have confirmed that we have a NodePort service running on port 30880. You might need to allow this port through the firewall.
Step 3 – Access KubeSphere Web UI
Using the port, you can then access the KubeSphere Web UI using the URL http://node_IP:30880
Login using the default account and password (admin/P@88w0rd). You will be required to set a preferred password. Thereafter, you will be authenticated to the below dashboard.
Now there are several ways to proceed. We will first look at the Platform information. We have one cluster configured as shown:
You can view the available nodes and their health.
View metrics for the various resources under monitoring and alerting.
You can also view the workspaces and the projects in the workspaces:
Navigate into any of the workspaces and view the workloads, storage, configurations etc.
Step 4 – Deploy an Ingress Controller Using KubeSphere
To deploy an Ingress Controller, first create a gateway under cluster settings as shown:
Once created, we need to get a Load Balancer IP. This can be achieved by first installing MetalLB on the Kubernetes cluster:
Once applied, you should have a Loadbalancer IP address for the gateway:
$ kubectl get svc -A
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 105m
kube-system kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 104m
kube-system kubelet ClusterIP None <none> 10250/TCP,10255/TCP,4194/TCP 85m
kube-system metrics-server ClusterIP 10.99.27.215 <none> 443/TCP 104m
kubesphere-controls-system default-http-backend ClusterIP 10.106.36.230 <none> 80/TCP 88m
kubesphere-controls-system kubesphere-router-kubesphere-system LoadBalancer 10.109.128.248 192.168.205.40 80:30422/TCP,443:30652/TCP 8m13s
kubesphere-controls-system kubesphere-router-kubesphere-system-metrics ClusterIP 10.102.198.248 <none> 10254/TCP 8m13s
.....Now proceed and create an ingress under application workloads.
Add a sample routing rule for the KubeSphere console service:
Finish creating the ingress controller.
After mapping the Load Balancer IP address to the domain name in /etc/hosts, try accessing the service to verify if the Ingress Controller is working:
Books For Learning Kubernetes Administration:
Verdict
Today, we have learned how to install and use KubeSphere on an existing Kubernetes cluster. We have only covered a few use scenarios for KubeSphere. We can now agree that simplifies the complexity of Kubernetes and makes it more accessible to developers and other users. It allows users to easily manage multiple clusters and deploy applications with just a few clicks. It also provides tools for monitoring and scaling applications, which helps to ensure that they are running smoothly and efficiently.
Interested in more?
- Managing Kubernetes Cluster using Portainer Web Dashboard
- How To Install and Use Headlamp Kubernetes Web UI
- Build container images from Dockerfile using kaniko in Kubernetes
- Build container images on Kubernetes using img image builder
