Day 20 Docker For DevOps Engineers!!

Let's Learn docker commands:

Create and run a container in the background

$ docker run -d -p 80:80 docker/getting-started

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• -d - Run the container in detached mode

• -p 80:80 - Map port 80 to port 80 in the container

• docker/getting-started - The image to use

Create and run a container in foreground

$ docker run -it -p 8001:8080 --name my-nginx nginx

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• -it - Interactive bash mode

• -p 8001:8080 - Map port 8001 to port 8080 in the container

• --name my-nginx - Specify a name

• nginx - The image to use

General commands

docker ps	List running containers
docker ps -a	List all containers
docker ps -s	List running containers (with CPU / memory)
docker images	List all images
docker exec -it <container> bash	Connecting to container
docker logs <container>	Shows container's console log
docker stop <container>	Stop a container
docker restart <container>	Restart a container
docker rm <container>	Remove a container
docker port <container>	Shows container's port mapping
docker top <container>	List processes
docker kill <container>	Kill a container

Parameter <container> can be container id or name

#Docker Containers

Starting & Stopping

docker start my-nginx	Starting
docker stop my-nginx	Stopping
docker restart my-nginx	Restarting
docker pause my-nginx	Pausing
docker unpause my-nginx	Unpausing
docker wait my-nginx	Blocking a Container
docker kill my-nginx	Sending a SIGKILL
docker attach my-nginx	Connecting to an Existing Container

Information

docker ps	List running containers
docker ps -a	List all containers
docker logs my-nginx	Container Logs
docker inspect my-nginx	Inspecting Containers
docker events my-nginx	Containers Events
docker port my-nginx	Public Ports
docker top my-nginx	Running Processes
docker stats my-nginx	Container Resource Usage
docker diff my-nginx	Lists the changes made to a container.

Creating

docker create [options] IMAGE
  -a, --attach               # attach stdout/err
  -i, --interactive          # attach stdin (interactive)
  -t, --tty                  # pseudo-tty
      --name NAME            # name your image
  -p, --publish 5000:5000    # port map (host:container)
      --expose 5432          # expose a port to containers
  -P, --publish-all          # publish all ports
      --link container:alias # linking
  -v, --volume `pwd`:/app    # mount (absolute paths needed)
  -e, --env NAME=hello       # env vars

Example

$ docker create --name my_redis --expose 6379 redis:3.0.2

Manipulating

Renaming a Container

docker rename my-nginx my-nginx

Removing a Container

docker rm my-nginx

Updating a Container

docker update --cpu-shares 512 -m 300M my-nginx

#Docker Images

Manipulating

docker images	Listing images
docker rmi nginx	Removing an image
docker load < ubuntu.tar.gz	Loading a tarred repository
docker load --input ubuntu.tar	Loading a tarred repository
docker save busybox > ubuntu.tar	Save an image to a tar archive
docker history	Showing the history of an image
docker commit nginx	Save a container as an image.
docker tag nginx eon01/nginx	Tagging an image
docker push eon01/nginx	Pushing an image

Building Images

$ docker build .
$ docker build github.com/creack/docker-firefox
$ docker build - < Dockerfile
$ docker build - < context.tar.gz
$ docker build -t eon/my-nginx .
$ docker build -f myOtherDockerfile .
$ curl example.com/remote/Dockerfile | docker build -f - .

#Docker Networking

Manipulating

Removing a network

docker network rm MyOverlayNetwork

Listing networks

docker network ls

Getting information about a network

docker network inspect MyOverlayNetwork

Connecting a running container to a network

docker network connect MyOverlayNetwork nginx

Connecting a container to a network when it starts

docker run -it -d --network=MyOverlayNetwork nginx

Disconnecting a container from a network

docker network disconnect MyOverlayNetwork nginx

Creating Networks

docker network create -d overlay MyOverlayNetwork

docker network create -d bridge MyBridgeNetwork

docker network create -d overlay \
  --subnet=192.168.0.0/16 \
  --subnet=192.170.0.0/16 \
  --gateway=192.168.0.100 \
  --gateway=192.170.0.100 \
  --ip-range=192.168.1.0/24 \
  --aux-address="my-router=192.168.1.5" \
  --aux-address="my-switch=192.168.1.6" \
  --aux-address="my-printer=192.170.1.5" \
  --aux-address="my-nas=192.170.1.6" \
  MyOverlayNetwork

#Clean Up

Clean All

Cleans up dangling images, containers, volumes, and networks (ie, not associated with a container)

docker system prune

---

Additionally, remove any stopped containers and all unused images (not just dangling images)

docker system prune -a

Containers

Stop all running containers

docker stop $(docker ps -a -q)

Delete stopped containers

docker container prune

Images

Remove all dangling (not tagged and is not associated with a container) images:

docker image prune

Remove all images which are not used by existing containers

docker image prune -a

Volumes

docker volume prune

Remove all volumes not used by at least one container

#Miscellaneous

Docker Hub

docker search search_word	Search docker hub for images.
docker pull user/image	Downloads an image from docker hub.
docker login	Authenticate to docker hub
docker push user/image	Uploads an image to docker hub.

Registry commands

Login to a Registry

$ docker login
$ docker login localhost:8080

Logout from a Registry

$ docker logout
$ docker logout localhost:8080

Searching an Image

$ docker search nginx
$ docker search nginx --stars=3 --no-trunc busybox

Pulling an Image

$ docker pull nginx
$ docker pull eon01/nginx localhost:5000/myadmin/nginx

Pushing an Image

$ docker push eon01/nginx
$ docker push eon01/nginx localhost:5000/myadmin/nginx

Batch clean

docker stop -f $(docker ps -a -q)	Stopping all containers
docker rm -f $(docker ps -a -q)	Removing all containers
docker rmi -f $(docker images -q)	Removing all images

Volumes

Check volumes

$ docker volume ls

Cleanup unused volumes

$ docker volume prune

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