zephery / ks-installer

Install KubeSphere on existing kubernetes cluster

Install KubeSphere on Existing Kubernetes Cluster

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In addition to supporting deploy on VM and BM, KubeSphere also supports installing on cloud-hosted and on-premises Kubernetes clusters,

Prerequisites

• Kubernetes Version: >= 1.13.0
• Helm Version: >= 2.10.0

1. Make sure your Kubernetes version is greater than 1.13.0, run kubectl version in your cluster node. The output looks like the following:

root@kubernetes:~# kubectl version
Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.1", GitCommit:"4485c6f18cee9a5d3c3b4e523bd27972b1b53892", GitTreeState:"clean", BuildDate:"2019-07-18T09:09:21Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.1", GitCommit:"4485c6f18cee9a5d3c3b4e523bd27972b1b53892", GitTreeState:"clean", BuildDate:"2019-07-18T09:09:21Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}

Pay attention to Server Version line, if GitVersion is greater than v1.13.0, it's good. Otherwise you need to upgrade your kubernetes first. You can refer to Upgrading kubeadm clusters from v1.12 to v1.13.

2. Make sure you've already installed Helm, and it's version is greater than 2.10.0. You can run helm version to check, the output looks like below:

root@kubernetes:~# helm version
Client: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}

If you get helm: command not found, it means Helm is not installed yet. You can check this doc Install Helm to find out how to install Helm, and don't forget to run helm init first after installation.

If you use an older version (<2.10.0), you need to upgrade your helm first. Upgrading Tiller

3. Check the available resources in your cluster is meets the requirement. For allinone installation, means there is just one node in your cluster, you must have at least 10Gi memory left to finish installation. You can run free -g to get a roughly estimate.

root@kubernetes:~# free -g
              total        used        free      shared  buff/cache   available
Mem:              16          4          10           0           3           2
Swap:             0           0           0

4. (Optional) Check if there is default storage class in your class. This is not required, but it's highly recommended use a Persistent Volume (not local volume).

root@kubernetes:~$ kubectl get sc
NAME                      PROVISIONER               AGE
ceph                      kubernetes.io/rbd         3d4h
csi-qingcloud (default)   disk.csi.qingcloud.com    54d
glusterfs                 kubernetes.io/glusterfs   3d4h

If your Kubernetes cluster environment meets all above requirements, you are good to go.

Note:

• Make sure the remaining available memory in the cluster is 10G at least.
• It's recommended that the K8s cluster use persistent storage and has created default storage class.

To Start Deploying KubeSphere

1. First, you need to create 2 namespaces in Kubernetes cluster, named kubesphere-system and kubesphere-monitoring-system.

$ cat <<EOF | kubectl create -f -
---
apiVersion: v1
kind: Namespace
metadata:
    name: kubesphere-system
---
apiVersion: v1
kind: Namespace
metadata:
    name: kubesphere-monitoring-system
EOF

2. Create the Secret of CA certificate of your current Kubernetes cluster.

Note: Follow the certificate paths of ca.crt and ca.key of your current cluster to create this secret.

kubectl -n kubesphere-system create secret generic kubesphere-ca  \
--from-file=ca.crt=/etc/kubernetes/pki/ca.crt  \
--from-file=ca.key=/etc/kubernetes/pki/ca.key 

3. Create the Secret of certificate for ETCD in your Kubernetes cluster.

Note: Create with the actual ETCD certificate location of the cluster; If the ETCD does not have a configured certificate, an empty secret is created（The following command applies to the cluster created by Kubeadm）

Note: Create the secret according to the your actual path of ETCD for the k8s cluster;

• If the ETCD has been configured with certificates, refer to the following step:

$ kubectl -n kubesphere-monitoring-system create secret generic kube-etcd-client-certs  \
--from-file=etcd-client-ca.crt=/etc/kubernetes/pki/etcd/ca.crt  \
--from-file=etcd-client.crt=/etc/kubernetes/pki/etcd/healthcheck-client.crt  \
--from-file=etcd-client.key=/etc/kubernetes/pki/etcd/healthcheck-client.key

• If the ETCD has been not configured with certificates.

$ kubectl -n kubesphere-monitoring-system create secret generic kube-etcd-client-certs

4. Then we can start to install KubeSphere.

$ cd deploy

$ vim kubesphere.yaml   
# According to the parameter table at the bottom, replace the value of "kubesphere-config" in "kubesphere.yaml" file with your current Kubernetes cluster parameters (If the ETCD has no certificate, set etcd_tls_enable: False).

$ kubectl apply -f kubesphere.yaml

5. Inspect the logs of installation.

kubectl logs -n kubesphere-system $(kubectl get pod -n kubesphere-system -l job-name=kubesphere-installer -o jsonpath='{.items[0].metadata.name}') -f

6. Finally, you can access the Web UI via IP:NodePort, the default account is admin/P@88w0rd.

$ kubectl get svc -n kubesphere-system    
# Inspect the NodePort of ks-console, it's 30880 by default.

Configuration Table

Parameter		Description	Default
kube_apiserver_host		The address of kube-apiserver of your current Kubernetes cluster（i.e. IP:NodePort）
etcd_tls_enable		Whether to enable etcd TLS certificate authentication（True / False）	True
etcd_endpoint_ips		Etcd addresses, such as ETCD clusters, you need to separate IPs by commas（e.g.192.168.0.7,192.168.0.8,192.168.0.9）
etcd_port		ETCD Port (2379 by default, you can configure this parameter if you are using another port)	2379
disableMultiLogin		Whether to turn off multipoint login for accounts   （True / False）	True
elk_prefix		Logging index	logstash
keep_log_days		Log retention time (days)	7
metrics_server_enable		whether to install metrics_server    （True / False）	True
sonarqube_enable		whether to install Sonarqube           （True / False）	True
istio_enable		whether to install Istio           （True / False）	True
persistence	enable	Whether the persistent storage server is enabled   （True / False）（It is recommended tp enable persistent storage in a formal environment）
	storageClass	Enabling persistent storage requires that the storageClass has been created already in the cluster (The default value is empty, which means it'll use default StorageClass)	“”
containersLogMountedPath（Optional）		Mount path of container logs	"/var/lib/docker/containers"
external_es_url（Optional）		External Elasticsearch address, it supports integrate your external ES or install internal ES directly. If you have ES, you can directly integrate it into KubeSphere
external_es_port（Optional）		External ES port, supports integrate external ES
local_registry (Offline installation only)		Integrate with the local repository when deploy on offline environment（To use this parameter, import the installation image into the local repository using "scripts/downloader-docker-images.sh"）

Quick Start Guide

10 Quick Start guides of KubeSphere

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Installer RoadMap

• Support multiple public cloud and private cloud, network plug-ins and storage plug-ins.
• All components are designed to be loosely-coupled, and all features are pluggable. Installation will become very light and fast.