Docker Command

save image to .tar file:

docker save -o exportName.tar imageName

docker save imageName > exportName.tar

load .tar to image:

docker load -i image.tar

list images:

docker image ls

docker images

make container: 实例：制作自己的 Docker 容器

docker container run -p pcSidePort:containerSidePort -it imageName

check docker version:

docker version

check the state of docker:

docker ps -a

restart the container:

docker restart IDNumber

show front 100 line logs:

docker logs IDNumber -f --tail 100

start docker:

systemctl start docker

RHEL/CentOS 8 Preparation for Installation:

sudo dnf -y install iptables --nobest ||:
sudo dnf -y install iptables-services --nobest
sudo systemctl disable firewalld ||:
sudo systemctl disable nftables ||:
sudo systemctl enable --now iptables.service
sudo dnf rm -y podman
sudo dnf config-manager \
--add-repo=https://download.docker.com/linux/centos/docker-ce.repo
sudo sed -i '/ˆgpgkey=https:\/\/download.docker.com\/linux\/centos\/gpg/a module_hotfixes=True' \
/etc/yum.repos.d/docker-ce.repo
sudo dnf install -y --nobest docker-ce
yum erase podman buildah
sudo yum install docker-ce docker-ce-cli containerd.io
sudo systemctl enable --now docker
sudo systemctl status docker

Create docker user group:
sudo groupadd docker
set group password and make user become group administrator:
sudo gpasswd -a $USER docker
put user into a group:
sudo usermod -aG docker $USER
Switch the current non-root user group to the docker user group:
exec newgrp docker
veryfy it:
docker run hello-world

Installation of docker-compose:

ver1:

binary="docker-compose-$(uname -s)-$(uname -m)"
compose=/usr/local/bin/docker-compose
sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/$binary" -o $compose
sudo chmod +x $compose
sudo restorecon -v $compose

ver2:

sudo curl -L "https://github.com/docker/compose/releases/download/v2.29.2/$binary" -o $compose

The restorecon command is only needed in an SELinux environment.

check all the output log of the containers in docker:

docker-compose logs

show the node in cluster:

docker node ls

show the network in docker:

docker network ls

show current stack:

docker stack ls

then show task in the stack:

docker stack ps stackName

show docker system information:

docker info

get container’s metadata:

docker inspect IDname

about docker plugin:

docker plugin命令

docker plugin COMMAND

how to change docker network setting(docker0):

docker のネットワーク (docker0) 設定変更

check docker config:

docker config ls

get into the container:

docker exec -it ContainerID bash

set proxy for docker:

sudo vi /etc/systemd/system/docker.service.d/http-proxy.conf

Then fill in the proxy server content:

[Service]
Environment="HTTP_PROXY=http://xxx:PortNumber"
Environment="HTTPS_PROXY=http://xxx:PortNumber"

then restart docker and test the content:

sudo systemctl daemon-reload
sudo systemctl restart docker
sudo systemctl show --property=Environment docker

How to save all Docker images and copy to another machine

start docker container, load from local otherwise from docker hub(-d means run background, -it means keep running):

docker run --restart=always --name containerName -p hostPort:containerPort -e firstEnvironmentVariable=xxx -it -d imageName:tagVersion

down load the container image: docker pull imageName

stop the container: docker stop containerID

start the container: docker start containerID

delete the container: docker rm containerID

delete the container image: docker rmi containerID:version

Dockerfile example(use ubuntu 20.04, as root, set env variable envVariableName, set work directory, use add to copy the file from internet, execute script.py then end container):

FROM ubuntu:20.04
USER root

RUN apt update
RUN apt install -y python3.9
RUN apt install -y python3-pip

COPY requirements.txt .
RUN python3.9 -m pip install -r requirements.txt

ENV envVariableName=xxx

WORKDIR /absolutePath
ADD https://xxx.xxx .

COPY script.py .
ENTRYPOINT ["python3.9", "script.py"]

create a docker image: docker build -t imageName:version -f Dockerfile .

Cannot install docker in a RHEL server —-> slirp4netns >= 0.4

check container automatically start status:

docker inspect -f "{{.Name}} {{.HostConfig.RestartPolicy.Name}}" $(docker ps -aq)

clear all the docker images:

docker stop $(sudo docker ps -aq)
docker rm $(sudo docker ps -aq)
docker rmi $(sudo docker images -q)
docker system prune -a

resource usage statistics:
docker stats
docker stats container_id_or_name

clean unused Docker resources:

docker system prune -a