2. Common commands for docker image containers

2. Common commands for docker image containers2.1. Do not use sudo command2.2, Help command2.3, Image command2.4. Container command2.5, other commonly used commands2.6 Command Summary

2.1. Do not use sudo command

Usually, you need to add the prefix sudo to operate the docker command, as follows:


sudo docker version

However, after adding the docker user group, you do not need to add the sudo prefix. How to add the docker user group (run the command in the host running docker):


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sudo groupadd docker # Add docker user group
sudo gpasswd -a $USER docker # Add the current user to the docker user group, where $USER can be automatically resolved to the currently logged in user
newgrp docker # Update the docker user group

After adding the above command, use the [docker images] command to test. If there is no error, it means that the sudo command can no longer be used. If the following error is reported:


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pi@yahboom:~$ docker images
WARNING: Error loading config file: /home/pi/.docker/config.json: open /home/pi/.docker/config.json: permission denied

Then execute the following command in the host to solve it:


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sudo chown "$USER":"$USER" /home/"$USER"/.docker -R
sudo chmod g+rwx "/home/$USER/.docker" -R

2.2, Help command


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docker info # Display Docker system information, including the number of images and containers. 。
docker --help # Help

2.3, Image command

1, docker pull download image


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# Download image
pi@yahboom:~$ docker pull ubuntu
Using default tag: latest # No tag, default is latest
latest: Pulling from library/ubuntu
cd741b12a7ea: Pull complete # Layered download
Digest: sha256:67211c14fa74f070d27cc59d69a7fa9aeff8e28ea118ef3babc295a0428a6d21
Status: Downloaded newer image for ubuntu:latest
docker.io/library/ubuntu:latest # Real location

2, docker images list images


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# List the images on the local host pi@yahboom:~$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE yahboomtechnology/ros-foxy 3.4.0 49581aa78b6b About an hour ago 24.3GB yahboomtechnology/ros-foxy 3.3.9 cefb5ac2ca02 3 days ago 20.5GB yahboomtechnology/ros-f oxy 3.3.8 49996806c64a 4 days ago 20.5GB yahboomtechnology/ros-foxy 3.3.7 8989b8860d17 4 days ago 17.1GB yahboomtechnology/ros-foxy 3.3.6 326531363d6e 5 days ago 16.1GB hello-world latest 46331d942d63 13 months ago 9.14kB

# Explanation
REPOSITORY The repository source of the image
TAG The tag of the image
IMAGE ID The ID of the image
CREATED The image creation time
SIZE The image size

# The same repository source can have multiple TAGs, representing different versions of this repository source. We use REPOSITORY: TAG to define different images. If you do not define the tag version of the image, docker will use the lastest image by default!

# Optional
-a: List all local images
-q: Display image ID only
--digests: Display image summary information

docker search Search image


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# Search image
pi@yahboom:~$ docker search ros2
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
osrf/ros2 **Experimental** Docker Images for ROS2 deve… 60 [OK]
tiryoh/ros2-desktop-vnc A Docker image to provide HTML5 VNC interfac… 11
althack/ros2 An assortment of development containers for … 7
tiryoh/ros2 unofficial ROS2 image 6
athackst/ros2 [Deprecated-> use althack/ros2] 5
uobflightlabstarling/starling-mavros2 ROS2 version of MAVROS 2
theosakamg7/ros2_java_docker Image base 1 [OK]

# docker search The name of a certain image corresponds to the image in the DockerHub repository

# Optional
--filter=stars=50: List images with a collection count not less than the specified value.

docker rmi delete image


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# Delete image
docker rmi -f image id # Delete a single
docker rmi -f image name: tag image name: tag # Delete multiple
docker rmi -f $(docker images -qa) # Delete all

2.4. Container command

docker run runs the image to start the container


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# Command
docker run [OPTIONS] IMAGE [COMMAND][ARG...]
# Common parameter description
--name="Name" # Assign a name to the container
-d # Run the container in the background and return the container id!
-i # Run the container in interactive mode, used with -t
-t # Reassign a terminal to the container, usually used with -i
-P # Random port mapping (uppercase)
-p # Specify port mapping (summary), generally there are four ways to write
ip:hostPort:containerPort
ip::containerPort
hostPort:containerPort (common)
containerPort

#test
pi@yahboom:~$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
yahboomtechnology/ros-foxy 3.4.0 49581aa78b6b 2 hours ago 24.3GB
yahboomtechnology/ros-foxy 3.3.9 cefb5ac2ca02 3 days ago 20.5GB
yahboomtechnology/ros-foxy 3.3.8 49996806c64a 4 days ago 20.5GB
yahboomtechnology/ros-foxy 3.3.7 8989b8860d17 4 days ago 17.1GB
yahboomtechnology/ros-foxy 3.3.6 326531363d6e 5 days ago 16.1GB
ubuntu latest bab8ce5c00ca 6 weeks ago 69.2MB
hello-world latest 46331d942d63 13 months ago 9.14kB

#Use ubuntu to start the container in interactive mode and execute the /bin/bash command in the container!
pi@yahboom:~$ docker run -it ubuntu:latest /bin/bash
root@c54bf9efae47:/# ls
bin boot dev etc home lib media mnt opt proc root run sbin srv sys tmp usr var
root@c54bf9efae47:/# exit # Use exit to exit the container and return to the host
exit
pi@yahboom:~$

docker ps lists all running containers


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# Command
docker ps [OPTIONS]
# Common parameter description
-a # List all currently running containers + historically run containers
-l # Display the most recently created container
-n=? # Display the most recently created n containers
-q # Silent mode, only display the container number.

#Test
pi@yahboom:~$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c54bf9efae47 ubuntu:latest "/bin/bash" 2 hours ago Up 4 seconds funny_hugle
3b9c01839579 hello-world "/hello" 3 hours ago Exited (0) 3 hours ago jovial_brown

Exit the container


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exit # Stop the container and exit
ctrl+P+Q # Do not stop the container and exit

Enter the running container from multiple terminals


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# Command 1
docker exec -it container id bashShell

# Test
pi@yahboom:~$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c54bf9efae47 ubuntu:latest "/bin/bash" 2 hours ago Up 4 seconds funny_hugle
3b9c01839579 hello-world "/hello" 3 hours ago Exited (0) 3 hours ago jovial_brown
pi@yahboom:~$ docker exec -it c5 /bin/bash # The container ID can be abbreviated as long as it can uniquely identify the container
root@c54bf9efae47:/#

# Command 2
docker attach container ID

# Test
pi@yahboom:~$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c54bf9efae47 ubuntu:latest "/bin/bash" 2 hours ago Up 35 seconds funny_hugle
3b9c01839579 hello-world "/hello" 3 hours ago Exited (0) 3 hours ago jovial_brown
pi@yahboom:~$ docker attach c5 # The container ID can be abbreviated as long as it can uniquely identify the container
root@c54bf9efae47:/#

# Difference
# exec opens a new terminal in the container and can start a new process
# attach directly enters the terminal of the container start command and does not start a new process

Start and stop containers


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docker start (container id or container name) # Start the container
docker restart (container id or container name) # Restart the container
docker stop (container id or container name) # Stop the container
docker kill (container id or container name) # Force stop the container

Delete the container


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docker rm container id # Delete the specified container
docker rm -f $(docker ps -a -q) # Delete all containers
docker ps -a -q|xargs docker rm # Delete all containers

2.5, other commonly used commands

View the process information running in the container, supporting ps command parameters.


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# Command
docker top container id

# Test
pi@yahboom:~$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c54bf9efae47 ubuntu:latest "/bin/bash" 2 hours ago Up 2 minutes funny_hugle
3b9c01839579 hello-world "/hello" 3 hours ago Exited (0) 3 hours ago jovial_brown
pi@yahboom:~$ docker top c5
UID PID PPID C STIME TTY TIME CMD
root 9667 9647 0 14:20 pts/0 00:00:00 /bin/bash

View the metadata of the container/image


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# command
docker inspect Container id

# Test to view container metadata
pi@yahboom:~$ docker ps -a
CONTAINER ID   IMAGE           COMMAND       CREATED       STATUS                   PORTS     NAMES
c54bf9efae47   ubuntu:latest   "/bin/bash"   2 hours ago   Up 4 minutes                       funny_hugle
3b9c01839579   hello-world     "/hello"      3 hours ago   Exited (0) 3 hours ago             jovial_brown
pi@yahboom:~$ docker inspect c54bf9efae47
[
    {
        # The complete ID, the container ID above, is the first few digits of the intercepted ID
        "Id": "c54bf9efae471071391202a8718b346d9af76cb1ff17741e206280603d6f0056",
        "Created": "2023-04-24T04:19:46.232822024Z",
        "Path": "/bin/bash",
        "Args": [],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 9667,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2023-04-24T06:20:58.508213216Z",
            "FinishedAt": "2023-04-24T06:19:45.096483592Z"
        },
    。。。。


# Test and view image metadata
pi@yahboom:~$ docker images
REPOSITORY                   TAG       IMAGE ID       CREATED         SIZE
ubuntu                       latest    bab8ce5c00ca   6 weeks ago     69.2MB
hello-world                  latest    46331d942d63   13 months ago   9.14kB
pi@yahboom:~$ docker inspect bab8ce5c00ca
[
    {
        "Id": "sha256:bab8ce5c00ca3ef91e0d3eb4c6e6d6ec7cffa9574c447fd8d54a8d96e7c1c80e",
        "RepoTags": [
            "ubuntu:latest"
        ],
        "RepoDigests": [
            "ubuntu@sha256:67211c14fa74f070d27cc59d69a7fa9aeff8e28ea118ef3babc295a0428a6d21"
        ],
        "Parent": "",
        "Comment": "",
        "Created": "2023-03-08T04:32:41.063980445Z",
        "Container": "094fd0c521be8c84d81524e4a5e814e88a2839899c56f654484d32d171c7195b",
        "ContainerConfig": {
            "Hostname": "094fd0c521be",
            .............
            "Labels": {
                "org.opencontainers.image.ref.name": "ubuntu",
                "org.opencontainers.image.version": "22.04"
            }
        },
        "DockerVersion": "20.10.12",
        "Author": "",
        "Config": {
            "Hostname": "",
            .........
            "Labels": {
                "org.opencontainers.image.ref.name": "ubuntu",
                "org.opencontainers.image.version": "22.04"
            }
        },
        "Architecture": "arm64",
        "Variant": "v8",
        "Os": "linux",
        "Size": 69212233,
        "VirtualSize": 69212233,
        "GraphDriver": {
            "Data": {
                "MergedDir": "/var/lib/docker/overlay2/8418b919a02d38a64ab86060969b37b435977e9bbdeb6b0840d4eb698280e796/merged",
                "UpperDir": "/var/lib/docker/overlay2/8418b919a02d38a64ab86060969b37b435977e9bbdeb6b0840d4eb698280e796/diff",
                "WorkDir": "/var/lib/docker/overlay2/8418b919a02d38a64ab86060969b37b435977e9bbdeb6b0840d4eb698280e796/work"
            },
            "Name": "overlay2"
        },
        "RootFS": {
            "Type": "layers",
            "Layers": [
                "sha256:874b048c963ab55b06939c39d59303fb975d323822a4ea48a02ac8dc635ea371"
            ]
        },
        "Metadata": {
            "LastTagTime": "0001-01-01T00:00:00Z"
        }
    }
]