Docker layered download understanding and docker submit its own image

1. Docker layered download understanding

All docker images originate from a basic image. When the image is modified or new content is added, a new image layer will be created on top of the current image layer.

The following example:


as shown in the figure, the tomcat image has 10 layers.

2. Docker submits its own image

1. Download an official tomcat mirror

Code:

docker pull tomcat

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2. Start the image in the background

Code:

docker run -d --name tomcat -p 8003:8080 tomcat

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3. Enter the container

Code:

docker exec -it tomcat /bin/bash

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4. Copy webapps.dist to webapps

Code:

cp -r webapps.dist/* webapps

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Test:
There is nothing in the official mirror webapps, and access will report that the resource cannot be found, but after I copy the things in webapps.dist to webapps, visit it again and the default interface of tomcat will appear, as shown below

5. Submit our modified image

Code:

docker commit -a="作者" -m="描述" 容器id 目标名字:版本

Screenshot: