Kubernetes Cluster Deployment¶
Introduction¶
Sealos is a simple Go binary that can be installed on most Linux operating systems. It can be flexibly used to deploy Kubernetes clusters.
Prerequisites¶
- Each cluster node should have a different hostname. Hostnames should not contain underscores.
- Time synchronization across all nodes.
- All nodes must be able to SSH into each other using the root user, and all nodes must have the same root password.
- Run the
sealos runcommand on the first node of the Kubernetes cluster; currently, external nodes do not support cluster installation. - It is recommended to use a clean operating system to create the cluster. Do not install Docker manually.
- Supports most Linux distributions, such as Ubuntu, CentOS, Rocky Linux.
- Supports using containerd as the container runtime.
- Use private IPs in public clouds.
Basic Information and Compatibility¶
| Hostname | IP Address | Role | Configuration |
|---|---|---|---|
| k8s-master | 192.168.100.101 | master | 4 CPU, 16G MEM, 100G DISK |
| K8s-node01 | 192.168.100.102 | node01 | 4 CPU, 16G MEM, 100G DISK |
| K8s-node02 | 192.168.100.103 | node02 | 4 CPU, 16G MEM, 100G DISK |
| Name | Description |
|---|---|
| Offline Installation Support | Yes |
| Supported Architectures | amd64/arm64 |
Installation Steps¶
1. Set Hostnames¶
Run the following commands respectively:
hostnamectl set-hostname k8s-master
hostnamectl set-hostname k8s-node01
hostnamectl set-hostname k8s-node02
2. Synchronize Host Time¶
Run the following commands on each node:
# Install ntpdate
yum install ntpdate -y
# Synchronize local time
ntpdate time.windows.com
# Synchronize with network source
ntpdate cn.pool.ntp.org
You can also set up crontab:
* */1 * * * /usr/sbin/ntpdate cn.pool.ntp.org
3. Install Sealos Command¶
Run the following command to install:
Verify the installation:
$ sealos -h
simplest way install kubernetes tools.
Usage:
sealos [command]
Available Commands:
add add some node
apply apply a kubernetes cluster
build build an cloud image from a Kubefile
completion Generate the autocompletion script for the specified shell
create Create a cluster without running the CMD
delete delete some node
exec exec a shell command or script on all node.
gen Generate a Clusterfile
help Help about any command
images list cloud image
load load cloud image
login login image repository
logout logout image repository
prune prune image
pull pull cloud image
push push cloud image
reset Simplest way to reset your cluster
rmi Remove one or more cloud images
run Simplest way to run your kubernetes HA cluster
save save cloud image to a tar file
scp copy local file to remote on all node.
tag tag a image as a new one
version version
Flags:
--cluster-root string cluster root directory (default "/var/lib/sealos")
--debug enable debug logger
-h, --help help for sealos
Use "sealos [command] --help" for more information about a command.
Installation is only required on one machine.
4. Install the Cluster¶
sealos run pubrepo.guance.com/googleimages/kubernetes:v1.24.0 \
pubrepo.guance.com/googleimages/calico:v3.22.1 \
--masters 192.168.100.101 \
--nodes 192.168.100.102,192.168.100.103 \
--passwd [your-ssh-passwd]
Note: Modify the IP addresses and password in the command.
Ensure you are logged in as the root user, and ensure ports are open between nodes.
Parameter Description:
| Parameter Name | Example Value | Parameter Description |
|---|---|---|
| --masters | 192.168.100.101 | List of Kubernetes master node IP addresses |
| --nodes | 192.168.100.102,192.168.100.103 | List of Kubernetes node IP addresses |
| --passwd | [your-ssh-passwd] | SSH login password |
| kubernetes | pubrepo.guance.com/googleimages/kubernetes:v1.24.0 | Kubernetes image |