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Building Cluster Images Based on the Image List

This document will guide you on how to build cluster images using the image list, including how to build a single image (based on pre-existing Kubernetes images) or build an application image from scratch.

Directory Structure​

.
├── Kubefile
├── cni
│   ├── custom-resources.yaml
│   └── tigera-operator.yaml
├── images
│   └── shim
│       └── CalicoImageList
└── registry
    └── docker
        └── registry

Dockerfile Building​

We can build all content into a single image (FROM labring/kubernetes) or use FROM scratch to build the image from scratch.

Single Image​

FROM labring/kubernetes:v1.24.0
COPY cni ./cni
COPY images ./images
COPY registry ./registry
CMD ["kubectl apply -f cni/tigera-operator.yaml","kubectl apply -f cni/custom-resources.yaml"]

Application Image​

This image does not include Kubernetes, so it should run in a cluster where Kubernetes is already installed.

FROM scratch
COPY cni ./cni
COPY images ./images
COPY registry ./registry
COPY manifests ./manifests
CMD ["kubectl apply -f cni/tigera-operator.yaml","kubectl apply -f cni/custom-resources.yaml"]

Notes:

  1. CalicoImageList: Docker image list file.
  2. cni: Configuration files for kubectl apply.
  3. registry: Directory for storing container registry data.
  4. sealos build -t kubernetes-calico:1.24.0-amd64 --platform linux/amd64 -f Kubefile .: Command for building the OCI image.
  5. manifests: Resolve images in the yaml file to a Docker image list.

Building Calico Image​

Directory Structure​

.
├── Kubefile
├── cni
│   ├── custom-resources.yaml
│   └── tigera-operator.yaml

Dockerfile Building​

All Together​

This image includes both Kubernetes and Calico.

FROM labring/kubernetes:v1.24.0-amd64
COPY cni ./cni
CMD ["kubectl apply -f cni/tigera-operator.yaml","kubectl apply -f cni/custom-resources.yaml"]

Application Image​

This image only contains Calico.

FROM scratch
COPY cni ./cni
CMD ["kubectl apply -f cni/tigera-operator.yaml","kubectl apply -f cni/custom-resources.yaml"]

Notes:

  1. cni: Configuration files for kubectl apply.
  2. sealos build -t kubernetes-calico:1.24.0-amd64 --platform linux/amd64 -f Kubefile .: Command for building the OCI image.

Building OpenEBS Image​

Directory Structure​

.
├── Kubefile
├── cni
│   ├── custom-resources.yaml
│   └── tigera-operator.yaml
└── manifests
    └── openebs-operator.yaml

Dockerfile Building​

All Together​

FROM labring/oci-kubernetes-calico:1.24.0-amd64
COPY cni ./cni
COPY manifests ./manifests
CMD ["kubectl apply -f cni/tigera

-operator.yaml","kubectl apply -f cni/custom-resources.yaml","kubectl apply -f manifests/openebs-operator.yaml"]

Application Image​

FROM scratch
COPY cni ./cni
COPY manifests ./manifests
CMD ["kubectl apply -f manifests/openebs-operator.yaml"]

Notes:

  1. cni: Configuration files for kubectl apply.
  2. sealos build -t labring/kubernetes-calico-openebs:1.24.0-amd64 --platform linux/amd64 -f Kubefile .: Command for building the OCI image.

Recommendation: You need to add the CMD of Calico to the CMD layer of OpenEBS because the Dockerfile will overwrite older layers.