source /dev/stdin <<< "$(curl -sSL https://raw.githubusercontent.com/fzinfz/scripts/master/linux/docker.sh)"

ENTRYPOINT [“exec_entry”, “p1_entry”]
CMD [“exec_cmd”, “p1_cmd”]
=> exec_entry p1_entry exec_cmd p1_cmd

RUN apt update && apt install -y 
    --no-install-recommends && rm -r /var/lib/apt/lists/*

# install pip3
RUN wget https://bootstrap.pypa.io/get-pip.py && python3 get-pip.py && rm get-pip.py
​
RUN apk add --no-cache --virtual .build-deps  \
    curl ca-certificates jq \
    && apk del .build-deps

docker run --init

When possible, overlay2 is the recommended storage driver. 
Supported backing filesystems: xfs with ftype=1, ext4 ( where /var/lib/docker/ is located )

docker build [-f Dockerfile.custom] [--target multi-stage] Dockerfile-Root-Folder
​
docker build - < Dockerfile      # no context, local ADD not working
curl example.com/remote/Dockerfile | docker build -f - .
Get-Content Dockerfile | docker build - # Powershell
​
docker build -f ctx/Dockerfile http://server/ctx.tar.gz
docker build https://github.com/user/repo.git

docker image tag SOURCE_IMAGE[:TAG] TARGET_IMAGE[:TAG]
​
docker export container_name > container.tar
docker import [OPTIONS] file|URL|- [REPOSITORY[:TAG]]
​
docker save image_name > image.tar
docker load < image.tar[.gz]
​
docker save python | ssh -C 192.168.88.72 docker load

docker cp [OPTIONS] CONTAINER:SRC_PATH DEST_PATH|-
docker cp [OPTIONS] SRC_PATH|- CONTAINER:DEST_PATH

--user=[ user | user:group | uid | uid:gid | user:gid | uid:group ]
​
-m, --memory=""
-c, --cpu-shares=0    CPU shares (relative weight)
--dns=[]           : Set custom dns servers for the container
--network="bridge" : Connect a container to a network
                      'bridge': create a network stack on the default Docker bridge
                      'none': no networking
                      'container:<name|id>': reuse another container's network stack
                      'host': use the Docker host network stack
                      '<network-name>|<network-id>': connect to a user-defined network
--network-alias=[] : Add network-scoped alias for the container
--add-host=""      : Add a line to /etc/hosts (host:IP)
--mac-address=""   : Sets the container's Ethernet device's MAC address
--ip=""            : Sets the container's Ethernet device's IPv4 address
--link-local-ip=[] : Sets one or more container's Ethernet device's link local IPv4/IPv6 addresses
--read-only        ：prohibiting writes to locations other than the specified volumes
​
Volume labels  
`:z` => shared  
`:Z` => private
​
`--entrypoint` will clear out `CMD`
​
echo test | docker run --rm -i alpine cat
docker run --security-opt seccomp:unconfined  # may fix chromium start error

--env="DISPLAY" --volume="$HOME/.Xauthority:/root/.Xauthority:rw"

docker container prune
docker system prune  # Remove unused data

Ctrl+p & Ctrl+q

/etc/docker/daemon.json     # delete `,` & `#...`
# `dockerd` for debugging: https://docs.docker.com/engine/admin/
{
    "live-restore": true,   # containers remain running if daemon unavailable
    "graph": "/data/docker-fs",
    "storage-driver": "overlay2",
}

mkdir -p /etc/systemd/system/docker.service.d
​
cat > /etc/systemd/system/docker.service.d/http-proxy.conf << EOF
[Service]
Environment="HTTP_PROXY=http://192.168.88.20:1080/" "NO_PROXY=localhost,127.0.0.1,192.168.*.*.172.16.*.*"
EOF
​
sudo systemctl daemon-reload
systemctl restart docker
​
systemctl show --property=Environment docker

docker swarm init --advertise-addr 10.2.0.1
docker swarm join-token manager
docker swarm join-token worker
docker swarm init --force-new-cluster # without losing data
​
docker node ls
docker node update --label-add server=s1 st
​
netstat -lntup | egrep '2377|7946|4789|50'
​
docker service create --name nginx -p 8080:80 --replicas 3 nginx
docker service create --name nginx -p 80:80  -p 443:443 --network web --mode global nginx
​
docker service ls
docker service ps nginx
docker inspect <ID> | grep Err

docker network create \
    --driver overlay \
    --subnet 10.66.3.0/24 \
    --opt encrypted \
    web
​
docker network ls
​
# node IP
ip addr | grep -P -o '\d+\.\d+\.\d+\.\d+(?=/24)'
​
# service VIP
ip addr | grep -P -o '\d+\.(?!255)\d+\.\d+\.\d+(?=/32)'

vi /etc/coreos/update.conf
update_engine_client -update

echo EXTRA_ARGS="--foo=bar"  >>  /var/lib/boot2docker/profile