Docker

De Linuxmemo.

Sommaire 1 Install 2 via proxy http 3 Containers 3.1 Lifecycle 3.2 Starting and Stopping 3.3 Info 3.4 Import / Export 3.5 Executing Commands 4 Images 4.1 Lifecycle 4.2 Info 4.3 Cleaning up 5 Networks 5.1 Lifecycle 5.2 Info 5.3 Connection 6 Registry & Repository 7 Layers 8 Volumes (persistent data) 8.1 Lifecycle 8.2 Info 9 Dockerfile 10 docker-compose 10.1 CLI docker-compose 10.2 "docker-compose.yml" reference 11 Astuces 12 Utilitaires 12.1 Docker-machine 12.2 Docker-compose 13 Cluster (orchestrateur) 13.1 Swarm 13.2 Kubernetes

[modifier] Install

apt-get install docker.io

[modifier] via proxy http

https://docs.docker.com/engine/admin/systemd/#http-proxy

sudo mkdir /etc/systemd/system/docker.service.d
sudo vim /etc/systemd/system/docker.service.d/http-proxy.conf
[Service]
Environment="HTTP_PROXY=http://proxy.example.com:80/" "HTTPS_PROXY=https://proxy.example.com:80/"
sudo systemctl daemon-reload
sudo systemctl show --property=Environment docker
sudo systemctl restart docker

[modifier] Containers

Source: https://github.com/wsargent/docker-cheat-sheet/blob/master/README.md

[modifier] Lifecycle

   docker create creates a container but does not start it.
   docker rename allows the container to be renamed.
   docker run creates and starts a container in one operation.
   docker rm deletes a container.
   docker update updates a container's resource limits.

[modifier] Starting and Stopping

   docker start starts a container so it is running.
   docker stop stops a running container.
   docker restart stops and starts a container.
   docker pause pauses a running container, "freezing" it in place.
   docker unpause will unpause a running container.
   docker wait blocks until running container stops.
   docker kill sends a SIGKILL to a running container.
   docker attach will connect to a running container.

[modifier] Info

   docker ps shows running containers.
   docker logs gets logs from container. (You can use a custom log driver, but logs is only available for json-file and journald in 1.10)
   docker inspect looks at all the info on a container (including IP address).
   docker events gets events from container.
   docker port shows public facing port of container.
   docker top shows running processes in container.
   docker stats shows containers' resource usage statistics.
   docker diff shows changed files in the container's FS.

   docker ps -a shows running and stopped containers.
   docker stats --all shows a running list of containers.

[modifier] Import / Export

   docker cp copies files or folders between a container and the local filesystem..
   docker export turns container filesystem into tarball archive stream to STDOUT.

[modifier] Executing Commands

   docker exec to execute a command in container.
   To enter a running container, attach a new shell process to a running container called foo, use: docker exec -it foo /bin/bash.

[modifier] Images

https://hub.docker.com/

[modifier] Lifecycle

   docker images shows all images.
   docker import creates an image from a tarball.
   docker build creates image from Dockerfile.
   docker commit creates image from a container, pausing it temporarily if it is running.
   docker rmi removes an image.
   docker load loads an image from a tar archive as STDIN, including images and tags (as of 0.7).
   docker save saves an image to a tar archive stream to STDOUT with all parent layers, tags & versions (as of 0.7).

[modifier] Info

   docker history shows history of image.
   docker tag tags an image to a name (local or registry).

[modifier] Cleaning up

   docker rmi command to remove specific images, there's a tool called docker-gc that will clean up images that are no longer used by any containers in a safe manner.

[modifier] Networks

[modifier] Lifecycle

   docker network create
   docker network rm

[modifier] Info

   docker network ls
   docker network inspect

[modifier] Connection

   docker network connect
   docker network disconnect

You can specify a specific IP address for a container:

# create a new bridge network with your subnet and gateway for your ip block
docker network create --subnet 203.0.113.0/24 --gateway 203.0.113.254 iptastic

# run a nginx container with a specific ip in that block
$ docker run --rm -it --net iptastic --ip 203.0.113.2 nginx

# curl the ip from any other place (assuming this is a public ip block duh)
$ curl 203.0.113.2

[modifier] Registry & Repository

   docker login to login to a registry.
   docker logout to logout from a registry.
   
   docker search searches registry for image.
   docker search --filter is-official=true --no-trunc busybox

   docker pull pulls an image from registry to local machine.
   docker push pushes an image to the registry from local machine.

[modifier] Layers

    docker run -d --link CONTAINER:ALIAS --name LINKED user/wordpress

[modifier] Volumes (persistent data)

[modifier] Lifecycle

   docker volume create
   docker volume rm

[modifier] Info

   docker volume ls
   docker volume inspect

[modifier] Dockerfile

   .dockerignore
   FROM Sets the Base Image for subsequent instructions.
   MAINTAINER Set the Author field of the generated images..
   RUN execute any commands in a new layer on top of the current image and commit the results.
   CMD provide defaults for an executing container.
   EXPOSE informs Docker that the container listens on the specified network ports at runtime. NOTE: does not actually make ports accessible.
   ENV sets environment variable.
   ADD copies new files, directories or remote file to container. Invalidates caches. Avoid ADD and use COPY instead.
   COPY copies new files or directories to container.
   ENTRYPOINT configures a container that will run as an executable.
   VOLUME creates a mount point for externally mounted volumes or other containers.
   USER sets the user name for following RUN / CMD / ENTRYPOINT commands.
   WORKDIR sets the working directory.
   ARG defines a build-time variable.
   ONBUILD adds a trigger instruction when the image is used as the base for another build.
   STOPSIGNAL sets the system call signal that will be sent to the container to exit.
   LABEL apply key/value metadata to your images, containers, or daemons.

[modifier] docker-compose

Initialement Fig (développé lors du hackthlon de novembre 2014). Intégrer dans la stack Docker comme docker-compose.

Ref: https://docs.docker.com/v1.8/compose/yml/

[modifier] CLI docker-compose

Usage:
 docker-compose [-f=<arg>...] [options] [COMMAND] [ARGS...]
 docker-compose -h|--help
Options:
 -f, --file FILE           Specify an alternate compose file (default: docker-compose.yml)
 -p, --project-name NAME   Specify an alternate project name (default: directory name)
 --x-networking            (EXPERIMENTAL) Use new Docker networking functionality.
                           Requires Docker 1.9 or later.
 --x-network-driver DRIVER (EXPERIMENTAL) Specify a network driver (default: "bridge").
                           Requires Docker 1.9 or later.
 --verbose                 Show more output
 -v, --version             Print version and exit

build
help
kill
logs
port
ps
pull
restart
rm
run
scale
start
stop
up -> docker-compose up -d

[modifier] "docker-compose.yml" reference

   image
   build
   dockerfile
   command
   links
   external_links
   extra_hosts
   ports
   expose
   volumes
   volumes_from
   environment
   env_file
   extends
   labels
   container_name
   log driver
   net
   pid
   dns
   cap_add, cap_drop
   dns_search
   devices
   security_opt
   working_dir, entrypoint, user, hostname, domainname, mac_address, mem_limit, memswap_limit, privileged, restart, stdin_open, tty, cpu_shares, cpuset, read_only, volume_driver

[modifier] Astuces

• run shell

docker container run -t -i ubuntu bash
-t (terminal)
-i (interactif)

• run background

docker container run -d nginx
-d (detach)

• port

-p HOST_PORT:CONTAINER_PORT
-P

• bind-mount (partage de répertoires host/container)

-v PATH_HOST:PATH_CONTAINER
ou
--mount type=bind,src=PATH_HOST,dst=PATH_CONTAINER

• limitations

docker container run --memory 32m -ti ...
docker container run --cpu 2 -ti ...

• droit du container (par défaut s'exec en root)

--user

• nommer le container (au lieu de l'ID)

--name nom

• ménage des fichiers tmp du container

--rm

• reboot auto

--restart=on-failure

• extraire un clé de "inspect"

docker container inspect --format 'Modèle:.NETworkSettings.IPaddress" containername

• logs en continu

docker container logs -f nomcontainer

• shell ou process dans un container en cours d'execution

docker container exec -ti nomcontainer bash

• fermer tout les container

docker container rm -f $(docker container ls -aq)

[modifier] Utilitaires

[modifier] Docker-machine

Création de VM hébergeant Docker sur de multiple environnement (notamment cloud) via plugin et API.

[modifier] Docker-compose

Gestion des application multi conteneurs.

• config: docker-compose.yml

[modifier] Cluster (orchestrateur)

[modifier] Swarm

Illustration de RAFT: http://thesecretlivesofdata.com/raft/

[modifier] Kubernetes