My Docker Cheat Sheet

Docker Cheat Sheet

Build and run a docker image

Build docker images from docker file, goto dockerfile directory and command:

docker build -t friendlynginx .

Run docker image from locally built image

docker run -d -p 50053:8088 friendlynginx
# -d for running it in background //50053:8088 is the exposed port

Connect with docker hub and push to directory, a directory maruftuhin/nginx is created i docker hub at first, then login

docker login
docker tag friendlynginx maruftuhin/nginx:tag
docker push maruftuhin/nginx

Pull image from docker hub:

docker pull maruftuhin/nginx:tag

Run image using tag , [if locally unavailable, it pulls from online]

docker run -p -d 4000:8088 maruftuhin/nginx:tag

List of images and containers

List of images

docker images

List all exited containers

docker ps -a -q -f status=exited

List of containers

docker ps -a
# -a for all

Stop/remove a container or image

Stop a container

docker stop <container_id>

Start a exited container

docker start <container id>

Remove an image

docker rmi <image_id>

Remove a container

docker rm <container id>
docker rm <container_name>

Remove more than one image/container

docker rm <container id> <container_id>

Making change in a container/image

Creates a container for a image and enters it directory

docker run -it <image_id> /bin/bash

Insert in a existing container [the container must be UP]

docker exec -it <container_id> bash
# example: docker exec -it ecf1310ac3ed bash

Anything can be installed in that container, example, at first insert into a container and command:

apt-get update
apt-get install fish
apt-get install php    #installs latest php

Exit container directory

exit

Creates a image/snapshot of a [may be modified] container

docker commit <container_id> new_id_of_image

Executing container commands

Start a exited container

docker start <container id>

Restart a crashed container

docker restart <contaienr_id>

Start fish in interactive mode

docker exec -it <container_id> fish

Start php inside container

docker exec -it <container_id> php -a
echo "hello world";
exit

Names of conatiners or Images

Rename existing container

docker rename <old_name> new_name

Giving the container a name, while rnning it

docker run -it --name newName <container_id> bash

Copy files from a container

Create a text file inside container. insert the container and command:

touch test.txt

Copy from container. Exit from container and command:

docker cp containerName:/test.txt .    #copies test.txt to host root

Copy into container

docker cp ./test1.txt  containerName:/

Container hostnames

Gives a new hostname to the container. it doesn’t change the Names of container. but when user is inside the container, it sees the hostname, in this case, it’s root@test.

docker run -it -h test.local <image_id> bash

Handling volumes

It links between a directory of host and directory of container. in command, left side of “:” defines the source of host direcotry and right side defines destination into container.In this case, changing in ~/data of directory of host machine also takes place changing in container automatically

Bind mounts, the pasth is absolute here

docker run -it --name test21 -v ~/data:/data <image_id> bash

Volume help

docker volume --help

Inspect a docker container

docker inspect <container_id>

Named volume [non-bind mount], here the path is not absolute

docker run -it  -v data:/data <container_id> bash

Used volumes of local machine in container

docker volume ls

If same volume is used in another container, they will share the volume.

docker run -it  -v data:/data <container_id> bash   //shares previous data volume

Remove docker volume, volume_name is available in docker volume ls

docker volume rm <volume_name>

Multiple volume

docker run -it  -v data:/data  -v myBin:/myBin <container_id> bash

Copy volume from another container

docker run -it --name slave --volume-from <master_container_id/Name> <image_id> bash

Inspect docker volume

docker volume inspect <volume_name>

Show danglisg volumes [not used by any container]

docker volume ls -f dangling=true

Remove one volume that is not used

docker volume rm <volume name>

Removing all unsed volumes

docker volume prune

Anonymous volume. –rm will delete anonymous volume after remove container. here /foo is a anonymous volume

docker run --rm -v /foo -v awesome:/bar busybox top

Untagged Images

Show untagged images

docker images -f "dangling=true" -q

Delete all untagged images

docker images -f "dangling=true" -q | xargs docker rmi

Delete multiple images

Delete images of same name

docker images --format '{{.Repository}}:{{.Tag}}' | grep 'imagename' | xargs docker rmi
# or,
docker images -q imagename | uniq | xargs docker rmi --force

Docker killer!!! :P

Stop all container

docker ps -a -q | xargs docker stop

Delete all container

docker ps -a -q | xargs docker rm

Removing all unused volumes

docker volume prune

Remove untagged dockers

docker images -q -f "dangling=true" | xargs docker rmi

Remove stopped containers

docker ps -aq --no-trunc -f status=exited | xargs docker rm

Remove all images

docker images -q | xargs docker rmi

Start fresh

Dangerous!!! Deletes everything!!

sudo systemctl stop docker.service
sudo rm -rf /var/lib/docker
sudo systemctl start docker.service

Copy Local images to Minikube

For bash

docker save <image-name> | pv | (eval $(minikube docker-env) && docker load)
# or,
docker save <image-name> | (eval $(minikube docker-env) && docker load)