2. Common commands for docker image containers

The operating environment and software and hardware reference configuration are as follows:

• Reference model: ROSMASTER X3

• Robot hardware configuration: Arm series main control, Silan A1 lidar, AstraPro Plus depth camera

• Robot system: Ubuntu (no version required) + docker (version 20.10.21 and above)

• PC virtual machine: Ubuntu (18.04) + ROS (Melodic)

• Usage scenario: Use on a relatively clean 2D plane

   

2.1. Do not use sudo command

Normally, to operate docker commands, you need to prefix sudo, as follows:

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sudo docker version

But after adding the docker user group, you don't 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 automatically resolve to the currently logged in user
newgrp docker # Update docker user group

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

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pi@ubuntu:~$ 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 on the host machine to solve the problem:

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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. Mirror command

1. docker pull download image

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# Download image
jetson@ubuntu:~$ docker pull ubuntu
Using default tag: latest # Do not write tag, the 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
jetson@ubuntu:~$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
yahboomtechnology/ros-melodic 1.4.1 f8c914ba3cff 7 weeks ago 23.1GB
hello-world latest 46331d942d63 13 months ago 9.14kB

# explain
REPOSITORY mirrored warehouse source
TAG The tag of the image
IMAGE ID ID of the image
CREATED Image creation time
SIZE image size

# The same warehouse source can have multiple TAGs, representing different versions of the warehouse 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: only display image id
--digests: Display summary information of the image

3. docker search search image

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# Search for images
jetson@ubuntu:~$ 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 warehouse
#optional
--filter=stars=50: List the images whose collection number is not less than the specified value.

4. docker rmi deletes the 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

A container can only be created if you have a mirror. We use the ubuntu mirror to test here. Download the mirror:

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docker pull ubuntu

1. docker run runs the image to start the container

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# Order
docker run [OPTIONS] IMAGE [COMMAND][ARG...]
# Common parameter descriptions
--name="Name" # Specify a name for the container
-d # Run the container in background mode 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 it
ip:hostPort:containerPort
ip::containerPort
hostPort:containerPort (commonly used)
containerPort

#test
jetson@ubuntu:~$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
yahboomtechnology/ros-melodic 1.4.1 f8c914ba3cff 7 weeks ago 23.1GB
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!
jetson@ubuntu:~$ 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
jetson@ubuntu:~$

2. docker ps lists all running containers

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# Order
docker ps [OPTIONS]
# Common parameter descriptions
-a # List all currently running containers + historically run containers
-l # Display recently created containers
-n=? # Display the last n created containers
-q # Silent mode, only the container number is displayed.

#test
jetson@ubuntu:~$ 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

3. Exit the container

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exit # Container stops exiting
ctrl+P+Q # Container exits without stopping

4. Enter the running container from multiple terminals

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# Command 1
docker exec -it container id bashShell

# test
jetson@ubuntu:~$ 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
jetson@ubuntu:~$ 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
jetson@ubuntu:~$ 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
jetson@ubuntu:~$ docker attach c5 # The ID of the container can be abbreviated, as long as it can uniquely identify the container.
root@c54bf9efae47:/#

# the difference
# exec opens a new terminal in the container and can start a new process
# attach directly enters the terminal of the container startup command and will not start a new process.

5. Start and stop the container

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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

6. 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

1. View the process information running in the container and support ps command parameters.

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# Order
docker top container id

# test
jetson@ubuntu:~$ 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
jetson@ubuntu:~$ docker top c5
UID PID PPID C STIME TTY TIME CMD
root 9667 9647 0 14:20 pts/0 00:00:00 /bin/bash

2. View the metadata of the container/image

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# Order
docker inspect container id

#Test to view container metadata
jetson@ubuntu:~$ 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
jetson@ubuntu:~$ 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 to view image metadata
jetson@ubuntu:~$ 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
jetson@ubuntu:~$ 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"
         }
     }
]

2.6. Command summary