在用docker pull ubuntu:20.04时遇到如下错误：

$ docker pull ubuntu:20.04         
Error response from daemon:
 Get "https://registry-1.docker.io/v2/": net/http: request canceled while waiting for connection 
 (Client.Timeout exceeded while awaiting headers) 

似乎是网络的问题，找了很多方法都解决不了，于是想绕过docker pull，直接下载image, 然后本地load.

python文件docker_pull_image.py放在这里

 python docker_pull.py ubuntu:20.04 -o ubuntu_20_04.tar
Multi-architecture image detected. Selecting appropriate manifest...
Total uncompressed size of all layers: 24.77 MB
Layer 0 verified successfully.
ubuntu:20.04 image (arm64) downloaded and saved as ubuntu_20_04.tar
Compressed tar size: 24.79 MB
Load the image using: docker load -i ubuntu_20_04.tar

再试一下hello-world

$ python docker_pull_image.py hello-world
No tag specified, using latest tag: latest
Multi-architecture image detected. Selecting appropriate manifest...
Total uncompressed size of all layers: 0.00 MB
Layer 0 verified successfully.
hello-world:latest image (amd64) downloaded and saved as hello-world_latest.tar
Compressed tar size: 0.01 MB
Load the image using: docker load -i hello-world_latest.tar

$ docker load -i hello-world_latest.tar
Loaded image: hello-world:latest

$ docker run -it hello-world

Hello from Docker!
This message shows that your installation appears to be working correctly.