Build Docker Image in a Pod in Kubernetes

利用 kaniko 在 kubernetes 集群中使用 pod 来进行镜像构建,并 push 到镜像仓库中。

pre-request Link to heading

  • kubernetes cluster
  • kaniko-executor image

构建 Link to heading

具体用法可以阅读 kaniko 项目的 README 文档,项目本身支持GCS BucketS3 BucketLocal DirectoryGit Repository四种 buildcontext 存储方案,在实际的使用中,感觉使用内部的文件服务器更加方便,添加了对直接 http/https 下载链接的支持,https://github.com/maoqide/kaniko。

quick start Link to heading

build yourself a image for kaniko executor Link to heading

# build yourself a image for kaniko executor
cd $GOPATH/src/github.com/GoogleContainerTools
git clone https://github.com/maoqide/kaniko
make images

start a file server if using http/https for buildcontext Link to heading

kaniko's build context is very similar to the build context you would send your Docker daemon for an image build; it represents a directory containing a Dockerfile which kaniko will use to build your image. For example, a COPY command in your Dockerfile should refer to a file in the build context.    

using minio as file server:

docker run -p 9000:9000 minio/minio server /data

create context.tar.gz Link to heading

# tar your build context including Dockerfile into context.tar.gz
tar -C <path to build context> -zcvf context.tar.gz .

upload to minio and generate a download url.

create secret on kubernetes Link to heading

# registry can also be a harbor or other registry.
kubectl create secret docker-registry regcred --docker-server=<your-registry-server> --docker-username=<your-name> --docker-password=<your-pword> --docker-email=<your-email>

create pod Link to heading

apiVersion: v1
kind: Pod
metadata:
  name: kaniko
spec:
  containers:
  - name: kaniko
    env:
    - name: DOCKER_CONFIG
      value: /root/.docker/
    image: harbor.guahao-inc.com/mqtest/executor
    args: [ "--context=http://download_url/context.tar.gz",
            "--destination=maoqide/test:latest",
            "--verbosity=debug",
		]
    volumeMounts:
      - name: kaniko-secret
        mountPath: /root
      - name: context
        mountPath: /kaniko/buildcontext/
  restartPolicy: Never
  volumes:
    - name: context
      emptyDir: {}
    - name: kaniko-secret
      secret:
        secretName: regcred
        items:
          - key: .dockerconfigjson
            path: .docker/config.json

env DOCKER_CONFIG is required for regidtry authorization, otherwise you would get an UNAUTHORIZED error.

kubectl create -f pod.yaml
[root@centos10 ~]$ kubectl get po
NAME                      READY     STATUS      RESTARTS   AGE
kaniko                    0/1       Completed   0          5h

and you can find your image pushed.