sealer

# Quick start

This guide covers how you can quickly get started using Sealer.

# Prerequisites for kubernetes

  1. Install the sealer locally.
  2. Prepare six hosts and record their IPs and passwords, the following conditions are recommended:
    1. Hardware: 4C8G + 50G(System Disk)
    2. OS: CentOS/RHEL 7.5、CentOS/RHEL 7.6、CentOS/RHEL 7.7、CentOS/RHEL 7.8、CentOS/RHEL 7.9
    3. Kernel: 4.18.*（Recommend）、4.19.* 、 3.10.*（>=3.10.0-1160）

# Install a kubernetes cluster

# run a kubernetes cluster
sealer run docker.io/sealerio/kubernetes:v1-22-15-sealerio-2  \
  --masters 192.168.0.2,192.168.0.3,192.168.0.4 \
  --nodes 192.168.0.5,192.168.0.6,192.168.0.7 --passwd xxx

Password reminder

The password cannot contain the $ environment variable character, as cobra cannot recognize it. You can run Sealer using one of the following methods: user \$、 '1234$a' OR "1234\$a"

[root@iZm5e42unzb79kod55hehvZ ~]# kubectl get node
NAME                    STATUS ROLES AGE VERSION
izm5e42unzb79kod55hehvz Ready master 18h v1.22.15
izm5ehdjw3kru84f0kq7r7z Ready master 18h v1.22.15
izm5ehdjw3kru84f0kq7r8z Ready master 18h v1.22.15
izm5ehdjw3kru84f0kq7r9z Ready <none> 18h v1.22.15
izm5ehdjw3kru84f0kq7raz Ready <none> 18h v1.22.15
izm5ehdjw3kru84f0kq7rbz Ready <none> 18h v1.22.15

# PREREQUISITES for k0s

  1. Install the sealer locally.
  2. prepare four hosts and record their IPs and passwords, the condition you should refer System-requirements

# Install a k0s cluster

sealer run docker.io/sealerio/k0s:v1-24-10-sealerio-1 \
  --masters 192.168.0.2 \
  --nodes 192.168.0.5,192.168.0.6,192.168.0.7 --passwd xxx

[root@iZm5e42unzb79kod55hehvZ ~]# kubectl get node
NAME                    STATUS ROLES AGE VERSION
izm5ehdjw3kru84f0kq7r9z Ready <none> 18h v1.24.10-k0s.0
izm5ehdjw3kru84f0kq7raz Ready <none> 18h v1.24.10-k0s.0
izm5ehdjw3kru84f0kq7rbz Ready <none> 18h v1.24.10-k0s.0

# Build an app image

To build an app image, start by creating a nginx.yaml file with the following content:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
  namespace: default
spec:
  replicas: 1
  selector:
    matchLabels:
      run: my-nginx
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
        - name: my-nginx
          image: nginx
          ports:
            - containerPort: 80

Next, create a Kubefile with the following content:

FROM scratch
APP nginx local://nginx.yaml
LAUNCH ["nginx"]

Finally, run the following command to build the app image:

sealer build -f Kubefile -t sealer-io/nginx:latest --type app-installer

# Run the app image

To run the app image, use the following command:

sealer run sealer-io/nginx:latest

You can check the pod by running the following command:

kubectl get pod -A

# Push the app image to the registry

To push the app image to the registry, use the following command:

sealer tag sealer-io/nginx:latest {registryDomain}/sealer-io/nginx:latest
sealer push {registryDomain}/sealer-io/nginx:latest

You can push the app image to Docker Hub, Ali ACR, or Harbor.

# Clean the cluster

If you want to clean the cluster, run the following command:

sealer delete -a

Please note that some information of the basic settings will be written to the cluster and stored in /root/.sealer/Clusterfile locally.

# SEE ALSO

← Installing Sealer →