Kubernetes Development Practice: Code Compilation and Image Building

1. Environment Preparation

Hardware requirements: 8 GB+ memory, 50 GB+ disk, CentOS 8, kernel 5.10.23.

Software setup:

Install development tools: sudo dnf update sudo dnf groupinstall "Development Tools"

Install Docker: yum install docker-ce-20.10.7 docker-ce-cli-20.10.7 containerd.io

Install jq: sudo dnf install jq

Install PyYAML: pip install pyyaml

Install etcd (optional for testing): export PATH="$GOPATH/src/k8s.io/kubernetes/third_party/etcd:${PATH}"

Install Go (required version depends on Kubernetes version – see table below)

Compatibility table:

Kubernetes

requires Go

1.0 - 1.2

1.4.2

1.3, 1.4

1.6

1.5, 1.6

1.7 - 1.7.5

1.7

1.8.1

1.8

1.8.3

1.9

1.9.1

1.10

1.9.1

1.11

1.10.2

1.12

1.10.4

1.13

1.11.13

1.14 - 1.16

1.12.9

1.17 - 1.18

1.13.15

1.19 - 1.20

1.15.5

1.21 - 1.22

1.16.7

1.23

1.17

1.24

1.18

1.25+

1.19

2. Clone Code and Branch Preparation

Clone the Kubernetes repository and checkout the desired tag (e.g., v1.20.8):

git clone https://github.com/kubernetes/kubernetes.git

git fetch --tags origin v1.20.8

Modify the source as needed (not detailed here).

3. Build Preparation

Prepare the required build images for the selected Kubernetes version:

k8s.gcr.io/build-image/kube-cross:v1.15.13-legacy-1
k8s.gcr.io/build-image/go-runner:v2.3.1-go1.15.13-buster.0
k8s.gcr.io/build-image/debian-iptables:buster-v1.6.1

These images can be pre‑downloaded to the build node.

4. Compilation and Image Build

Run the make command with specific build parameters:

KUBE_BUILD_PLATFORMS=linux/amd64 WHAT="cmd/kube-controller-manager" KUBE_BUILD_CONFORMANCE=n
KUBE_BUILD_HYPERKUBE=n KUBE_BUILD_PULL_LATEST_IMAGES=n make release-images

Explanation of parameters:

KUBE_BUILD_PLATFORMS – target architecture (linux/amd64).

WHAT – component to build (may be ignored, building all components).

KUBE_BUILD_CONFORMANCE – run conformance tests.

KUBE_BUILD_HYPERKUBE – create a hyperkube image.

KUBE_BUILD_PULL_LATEST_IMAGES – pull the latest base images.

After about ten minutes, the built image tarballs appear in _output/release-images/amd64/ :

kube-apiserver.tar  kube-controller-manager.tar  kube-proxy.tar  kube-scheduler.tar

5. Image Extraction

Load a specific component image into Docker:

docker load -i kube-controller-manager.tar

The image will then be visible via docker images .

6. Using the Custom Image

Update the static pod manifest (e.g., /etc/kubernetes/manifests/kube-controller-manager.yaml ) to reference the newly built image:

image:k8s.gcr.io/kube-controller-manager:v1.20.8
==>
image: k8s.gcr.io/kube-controller-manager-amd64:v1.20.8-2_a16dce2b0c61ed

After editing, the pod restarts with the new image, allowing verification that code changes are effective.

References

https://github.com/kubernetes/community/blob/master/contributors/devel/development.md

https://juejin.cn/post/6844903918720270350