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Building Cluster Images Based on Binary Files

This document primarily details how to use the sealos tool to package a single binary file (like helm or kustomize) into a cluster image and install them by deploying the cluster image on the master node. Using helm as an example, we will thoroughly discuss how to package a binary file into a cluster image.

Create a Build Workspace​

Firstly, create a base directory to serve as a build workspace:

$ mkdir ~/cluster-images

In the workspace, create an opt directory for storing the binary files:

$ cd cluster-images
$ mkdir opt/

Prepare the Binary File​

Next, we prepare the helm binary file. Here, we download from github release:

wget https://get.helm.sh/helm-v3.10.1-linux-amd64.tar.gz
tar -zxvf helm-v3.10.1-linux-amd64.tar.gz
chmod a+x linux-amd64/helm
mv linux-amd64/helm opt/

Create the Sealfile Required for Building the Image​

Create a file named Sealfile, with the following content:

FROM scratch
COPY opt ./opt
CMD ["cp opt/helm /usr/bin/"]

The current directory structure is as follows:

.
├── Sealfile
└── opt
    └── helm

Build the Cluster Image​

Now, everything is ready, and you can begin building the cluster image:

sealos build -t labring/helm:v3.10.1 .

Note: Firstly, you need to install the sealos command on the local host.

You can view the build log to understand the building process.

root@ubuntu:~/cluster-images# sealos build -t labring/helm:v3.10.1 .
...

View the built image, and now all the dependent binary files have been built into the cluster image:

root@ubuntu:~/cluster-images# sealos images
labring/helm                      v3.10.1          19ed4a24f0fe   3 minutes ago       45.1 MB

Push the Image​

You can push the image to any Docker image repository, the following command pushes the image to DockerHub:

sealos push labring/helm:v3.10.1

Note: Please use the sealos command to operate the cluster image; Docker commands are not supported.

If you are using a private image repository, you can use the sealos login command to log into your image repository, then push or pull the image.