DOCKER REFERENCE https://docs.docker.com/reference/
Docker status
docker info
Start docker daemon on linux
sudo service docker start
Add current user to docker group to avoid using sudo each time
sudo usermod -aG docker {user}
Docker container official hub is hub.docker.com.
Official root images without slash in name.
Pulling image without a tag means pulling the latest.
Pull a container
docker pull ubuntu
docker pull tomcat:<tag>
List pulled images
docker image ls
Run container from image and expose container port 8080 to outer port 80
docker container run -p 80:8080 -d tomcat
docker container run -it ubuntu
where -d for detached, -it to run interactively attached to terminal
List containers
docker container list
docker container list -a # -a for all including inactive
Delete all inactive containers
docker container prune
Stop container
docker container stop <id>
Ssh into docker container
docker container exec -it <id> bash
Get logs that container have produced
docker container logs <id>
docker container logs -f <id> # -f to follow log output
Create your own image from a container
docker container commit -a "comment" <id> <name>
Build an image from a dockerfile located in .
docker image build -t "name_of_the_image" .
Show resources consupmtion by a container:
docker stats <container_id>
Volume allows persisting data after container stop/restart.
Run a container with a volume attached and named jenkins_home.
If it is non-existing it will be created.
docker run -p 8080:8080 -v jenkins_home:/var/jenkins_home jenkins/jenkins:lts
❗ Do not confuse volumes and bind mounts - there are slightly different.
Bind mounts are not recommended.
Bind mounts look like -v {path}:{path}, volumes like {name}:{path}
❗ new syntax for volumes is --mount
List all created volumes:
docker volume ls
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Operates with "nodes" instead of one host machine.
Containers get distributed between available nodes
docker swarm <command>
Iniializes a swarm and makes this host a manager
docker swarm init
Iniializes swarm on a host with multiple networks requires to set network explicitly
docker swarm init --advertise-addr <10.0.16.7>
Adding a worker to the swarm
docker swarm join --token <swarm_token> <address>
Services are containers inside a swarm
docker service <command>
Services in swarm require "overlay" type network, not "bridge". It works across multiple nodes
docker network create --driver overlay <network_name>
Use service create instead of container run
docker service create -d --network <my_network> -e <...> --name <service_name, e.g. database> <image>
To show that service has been started randomly somewhere on some host inside the swarm
docker service ls
Checking logs from service
docker service logs -f <service_name>
Nodes can be managers and workers. Workers can not execute some commands to manage the swarm.
Manager nodes communicate with raft system: https://raft.github.io. Ususally managers number is N/2+1
docker node <command>
List hosts in this swarm
docker node ls
Stack is set of containers representing one whole application.
Managing stack is like using docker-compose
docker stack <command>
Launch stack in swarm from docker-compose.yaml.
No need to care of start order, because swarm will restart any service if it fails
docker stack deploy -c docker-compose.yaml "stack_name"