The basic docker operation part includes docker installation, docker startup, docker operation, docker shutdown, and docker deletion. It is mainly aimed at ordinary users and recommends systematic learning for those who need in-depth understanding.
docker basics
From the rookie tutorial [https://www.runoob.com/docker/docker-tutorial.html]
Docker is an open source application container engine, based on the Go language and open source following the Apache 2.0 protocol.
Docker allows developers to package their applications and dependent packages into a lightweight, portable container, and then publish to any popular Linux machine, it can also be virtualized.
Containers use the sandbox mechanism completely, and there will be no interfaces between them (apps similar to iPhone), and more importantly, the container performance overhead is extremely low.
Docker has been divided into CE (Community Edition: Community Edition) and EE (Enterprise Edition: Enterprise Edition) since version 17.03, we can use the Community Edition.
docker installation
Under the centos system, docker only supports version 7 and above. This article takes centos8 as an example.
Add a docker-ce repo source, and then install the dependencies, it may be prompted to add some command parameters to install the dependencies, just follow the prompts.
yum-config-manager \
--add-repo \
https://download.docker.com/linux/centos/docker-ce.repo
Then install docker
yum install -y https://download.docker.com/linux/fedora/30/x86_64/stable/Packages/containerd.io-1.2.13-3.2.fc30.x86_64.rpm
yum install docker-ce docker-ce-cli
If no error is reported, the installation is completed!
docker start
systemctl start docker
In this way, the docker service is started and you can start using the docker command
docker operation
There are many docker operations, and the more commonly used ones are downloading mirrors, loading mirrors, entering mirrors as administrators, copying from mirrors, copying into mirrors, mirroring internal updates, etc.
Docker download and install the image
In the winter of installing docker, I just simply wanted to download a deployed collaboration online service from the Internet for the online office browsing of nextcloud. Here is an example.
docker pull collabora/code
Through the above command, the image is downloaded to the local.
Run/start the image and generate a container
docker run -t -d -p 0.0.0.0:9980:9980 -e 'domain=192\\.168\\.1\\.110|192\\.168\\.33\\.145' -e "username=admin" -e "password=123456" --restart always --cap-add MKNOD collabora/code
The above code comes from the short book: https://www.jianshu.com/p/4082f998a05b
To run the image, mainly use docker run. Refer to the tutorial for specific usage: https://www.runoob.com/docker/docker-run-command.html
In addition, docker stop/stats/ps/restart… and so on are commonly used, not to explain them one by one.
Enter the container
When we run a container, we need to obtain the container ID (container ID) in order to operate on the specific container
docker ps -a
[External link image transfer failed. The source site may have an anti-leech link mechanism. It is recommended to save the image and upload it directly (img-YCUKOMJ7-1607782879159)(https://i.loli.net/2020/12/12/DRaxkCwoQh3iEFH.png )]
As shown in the last line of the above figure, you can see the container ID, and then we enter this container
docker exec -it 1e560fca3906 /bin/bash
Or enter the container as an administrator, so that you can modify the content in the container
docker exec -it --user root 1e560fca3906 /bin/bash
But for my container, the vim command is deleted, and I can't do anything, so the administrator needs to install commands on the container after logging in. To update, you first need to know the docker system type, the operation here is the operation of linux.
cat /etc/issue
Then I found that this docker is Ubuntu, and we also need to start from adding the source. Since vim cannot be used, we can do the following and add the source directly.
echo deb http://archive.ubuntu.com/ubuntu/ trusty main universe restricted multiverse >> /etc/apt/sources.list
Update the management toolkit and install vim
apt-get update
apt-get install vim
In this way, you will find that the container is actually another linux world, just a doll.
docker copy
Initially, I used this command because there was no vim command. I wanted to copy it out and put it back in. It turned out that even the user was not the same for this operation, which finally caused insufficient permissions. It is not recommended, but it may be useful, so let’s briefly talk about it for record.
Native-"docker
docker cp copy.txt 1e560fca3906:/usr/local/
docker-》local
docker cp 1e560fca3906:/usr/local/copy.txt /home/
Close the container, delete the container
docker stop 1e560fca3906
docker rm 1e560fca3906
There can also be batch methods to stop and delete all containers
docker stop $(docker ps -a -q) // stop停止所有容器
docker rm $(docker ps -a -q) // remove删除所有容器