【前言】 需求：离线部署提前下载镜像 环境：在一台可上网的服务器上安装了kubeadm 1.21.0 的机器上完成下载

1. 更换阿里镜像源

【报错】

直接用kubeadm下载报错如下：

[root@k8s-1-21 ~]#  kubeadm config images pull
W0706 10:55:11.149871    6561 version.go:102] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get "https://dl.k8s.io/release/stable-1.txt": dial tcp 34.107.204.206:443: connect: connection timed out
W0706 10:55:11.149926    6561 version.go:103] falling back to the local client version: v1.21.2
failed to pull image "k8s.gcr.io/kube-apiserver:v1.21.2": output: Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
, error: exit status 1
To see the stack trace of this error execute with --v=5 or higher

【分析】

国外的镜像下不下来也无所谓，反正我们初始化集群的时候可以指定镜像仓库。 所以我们此时也把镜像源的参数加上，下载阿里云的镜像。

【解决】

添加--image-repository registry.aliyuncs.com/google_containers 参数，指定镜像源

[root@k8s-1-21 ~]# kubeadm config images pull --image-repository registry.aliyuncs.com/google_containers
W0706 10:58:05.269162    6878 version.go:102] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get "https://dl.k8s.io/release/stable-1.txt": dial tcp 34.107.204.206:443: connect: connection timed out
W0706 10:58:05.269222    6878 version.go:103] falling back to the local client version: v1.21.2
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.21.2
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.21.2
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.21.2
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.21.2
[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.4.1
[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.4.13-0
failed to pull image "registry.aliyuncs.com/google_containers/coredns:v1.8.0": output: Error response from daemon: manifest for registry.aliyuncs.com/google_containers/coredns:v1.8.0 not found: manifest unknown: manifest unknown
, error: exit status 1
To see the stack trace of this error execute with --v=5 or higher

如上可见，除了coredns:v1.8.0 这个镜像没有其他镜像都成功下载了。 下边我们解决coredns:v1.8.0 这个镜像的问题。

2. coredns:v1.8.0 not found

阿里没有找到 coredns:v1.8.0这个镜像 我是去公网搜了一个，pull下来，改成registry.aliyuncs.com/google_containers/coredns:v1.8.0，试了是可以用的。

[root@master-01 ~]# docker search coredns:v1.8.0
NAME                       DESCRIPTION                              STARS               OFFICIAL            AUTOMATED
louwy001/coredns-coredns   k8s.gcr.io/coredns/coredns:v1.8.0        1

开始想用阿里云的latest版本，然后吧tag改成1.8.0 ，试了一下一直启动不起来 [root@edge-master ~]# kubectl get pod -n kube-system NAME READY STATUS RESTARTS AGE coredns-59d64cd4d4-78cz5 0/1 Running 0 9m30s coredns-59d64cd4d4-x4t45 0/1 Running 0 9m57s

3. 离线部署镜像使用

提供两个方案

【方案一】

把刚才下载的镜像传到每台服务器 init.yaml 文件修改为阿里云镜像仓库

imageRepository: registry.aliyuncs.com/google_containers

【方案二】

将刚才下载的镜像push到私有镜像仓库 init.yaml 文件修改为私有镜像仓库

imageRepository: harbocto.xxx.com.cn/kubernetes