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The Docker client is very simple, we can directly input the docker command to see all the command options of the Docker client.
w3codebox@w3codebox:~# docker
You can use the command docker command --help To gain a deeper understanding of the usage method of the specified Docker command.
For example, we want to view docker stats The specific usage of the command:
w3codebox@w3codebox:~# docker stats --help
If we do not have the ubuntu image locally, we can use the docker pull command to load the ubuntu image:
$ docker pull ubuntu
The following command uses the ubuntu image to start a container with the parameter to enter the container in command line mode:
$ docker run -it ubuntu /bin/bash
Parameter description:
-i: interactive operation.
-t: terminal.
ubuntu: ubuntu image.
/bin/bashThe command placed after the image name is the command, here we want an interactive Shell, so we use /bin/bash.
To exit the terminal, directly enter exit:
root@ed09e4490c57:/# exit
The command to view all containers is as follows:
$ docker ps -a
Click the image to view the full size:
Use docker start to start a stopped container:
$ docker start b750bbbcfd88
In most scenarios, we hope that Docker's service runs in the background, so we can pass -The d parameter specifies the container's running mode.
$ docker run -itd --name ubuntu-test ubuntu /bin/bash
Click the image to view the full size:
Note:added -The d parameter does not enter the container by default. To enter the container, you need to use the command docker exec(This will be introduced later).
The command to stop a container is as follows:
$ docker stop <container ID>
Stopped containers can be restarted with docker restart:
$ docker restart <container ID>
When using -d When the parameter is specified, the container will enter the background after starting. At this time, if you want to enter the container, you can use the following command to enter:
docker attach
docker execIt is recommended to use the docker exec command because it exits the container terminal without stopping the container.
attach command
The following demonstrates the use of the docker attach command.
$ docker attach 1e560fca3906
Note: If you exit this container, it will cause the container to stop.
exec command
The following demonstrates the use of the docker exec command.
docker exec -it 243c32535da7 /bin/bash
Note: If you exit this container, the container will not stop, which is why it is recommended that everyone use docker exec reason.
For more parameter descriptions, please use docker exec --Use the help command to view.
Export container
If you want to export a local container, you can use docker export Command.
$ docker export 1e560fca3906 > ubuntu.tar
Export container 1e560fca3906 Snapshot to local file ubuntu.tar.
This will export the container snapshot to a local file.
Import container snapshot
You can use docker import to import a container snapshot file as an image. The following example imports the snapshot file ubuntu.tar into the image test./ubuntu:v1:
$ cat docker/ubuntu.tar | docker import - test/ubuntu:v1
In addition, it can also be imported by specifying a URL or a directory, for example:
$ docker import http://example.com/exampleimage.tgz example/imagerepo
Usage for deleting a container docker rm Command:
$ docker rm -f 1e560fca3906
The following command can clean up all containers in a terminated state.
$ docker container prune
The container we ran earlier doesn't have any special use.
Next, let's try to build a web application using docker.
We will run a Python Flask application in the docker container to run a web application.
w3codebox@w3codebox:~# docker pull training/webapp # Load the image w3codebox@w3codebox:~# docker run -d -P training/webapp python app.py
Parameter Description:
-d:Run the container in the background.
-P:Randomly map the network ports used internally by the container to the host we use.
Use docker ps to view the containers we are running:
w3codebox@w3codebox:~# docker ps Use docker ps to view the containers we are running: d3d5e39ed9d3 training/CONTAINER ID ... IMAGE ... COMMAND ... ... PORTS32769->5000/tcp
webapp "python app.py" ... 0.0.0.0:
Here is more port information. 0.0.0.0:32769->5000/tcp
PORTS 5Docker has opened 32769 000 port (default Python Flask port) mapped to the host port
.
We can also access the WEB application through the browser at this time -p parameter to set a different port:
w3codebox@w3codebox:~$ docker run -d -p 5000:5000 training/webapp python app.py
docker psView the running containers
w3codebox@w3codebox:~# docker ps CONTAINER ID IMAGE PORTS NAMES bf08b7f2cd89 training/webapp ... 0.0.0.0:5000->5000/tcp wizardly_chandrasekhar d3d5e39ed9d3 training/webapp ... 0.0.0.0:32769->5000/tcp xenodochial_hoov
inside the container 5000 port mapped to our local host 5000 port.
through docker ps The command can view the port mapping of the containerdocker it also provides another shortcut docker port, using docker port can view the specific port mapping of the host port of the container (ID or name).
Above, the ID of the web application container we created is bf08b7f2cd89 The name is wizardly_chandrasekhar.
I can use docker port bf08b7f2cd89 or docker port wizardly_chandrasekhar to view the port mapping of the container.
w3codebox@w3codebox:~$ docker port bf08b7f2cd89 5000/tcp -> 0.0.0.0:5000
w3codebox@w3codebox:~$ docker port wizardly_chandrasekhar 5000/tcp -> 0.0.0.0:5000
docker logs [ID or name] can view the standard output inside the container.
w3codebox@w3codebox:~$ docker logs -f bf08b7f2cd89 * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit) 192.168.239.1 - - [09/May/2016 16:30:37] "GET / HTTP/1.1" 200 - 192.168.239.1 - - [09/May/2016 16:30:37] "GET /favicon.ico HTTP/1.1" 404 -
-f: lets docker logs like using tail -f to output the standard output inside the container.
From above, we can see that the application uses 5000 端口并且能够查看到应用程序的访问日志。
我们还可以使用 docker top 来查看容器内部运行的进程
w3codebox@w3codebox:~$ docker top wizardly_chandrasekhar UID PID PPID ... TIME CMD root 23245 23228 ... 00:00:00 python app.py
使用 docker inspect 来查看 Docker 的底层信息。它会返回一个 JSON 文件记录着 Docker 容器的配置和状态信息。
w3codebox@w3codebox:~$ docker inspect wizardly_chandrasekhar
[
{
"Id": "bf08b7f2cd897b5964943134aa6d373e355c286db9b9885b1f60b6e8f82b2b85",
"Created": "2018-09-17T01:41:26.174228707Z",
"Path": "python",
"Args": [
"app.py"
],
"State": {
"Status": "running",
"Running": true,
"Paused": false,
"Restarting": false,
"OOMKilled": false,
"Dead": false,
"Pid": 23245,
"ExitCode": 0,
"Error": "",
"StartedAt": "2018-09-17T01:41:26.494185806Z",
"FinishedAt": "0001-01-01T00:00:00Z"
},
......w3codebox@w3codebox:~$ docker stop wizardly_chandrasekhar wizardly_chandrasekhar
已经停止的容器，我们可以使用命令 docker start 来启动。
w3codebox@w3codebox:~$ docker start wizardly_chandrasekhar wizardly_chandrasekhar
docker ps -l 查询最后一次创建的容器：
# docker ps -l CONTAINER ID IMAGE PORTS NAMES bf08b7f2cd89 training/webapp ... 0.0.0.0:5000->5000/tcp wizardly_chandrasekhar
For running containers, we can use the docker restart command to restart them.
We can use the docker rm command to delete unnecessary containers
w3codebox@w3codebox:~$ docker rm wizardly_chandrasekhar wizardly_chandrasekhar
The container must be in a stopped state when deleting a container, otherwise the following error will be reported
w3codebox@w3codebox:~$ docker rm wizardly_chandrasekhar Error response from daemon: You cannot remove a running container bf08b7f2cd897b5964943134aa6d373e355c286db9b9885b1f60b6e8f82b2b85Stop the container before attempting removal or force remove