/getting-started-with-docker

Getting started with Docker

Setting up Docker Machine

  • Create a local virtualbox machine called default using docker-machine
  • Use docker-machine env to point Docker Machine at default

Sanity check

  • Try out docker-machine ls, docker ps, docker ps -a, docker images
    • Create aliases dkm, dk, and dki
  • Import images as needed using docker load -i <path to image file> if you have them locally, or docker pull node:latest node:onbuild redis mongo to pull them from Docker Hub

Basic docker run

  • Run a container off of the node:latest image, with no commands
  • Run a container off of the node:latest image but give it a command
  • Run a container off of the node:latest image but give it a persistent command
  • docker exec -it ... bash into the running container and add a web server
  • Stop the container and docker commit a new image from it
  • Run a container from the new image, issuing a node index.js command
  • Install dkrm and clean up

Dockerfiles

  • Make a Dockerfile to do the whole image building process we just did manually, with a command
  • Make a better Dockerfile that handles package.json
  • Replace with Dockerfile that utilizes node:onbuild

A web server container

  • Spin up a web server container called web, exposing ports. How do we know which url to visit?

Running multiple containers from a single image

  • Run several containers off your web server image, exposing different ports for each

Linking containers

  • Run a mongo container
  • Run a container from your web server image, linking it to the mongo container
  • Go check out the environmental variables now available to you in the web server container

docker-compose.yml

  • Compose an application running a web server with exposed ports, linked to an also running mongo container

Create machine on Digital Ocean

  • Create account and get access key
  • Create the machine
  • Use Docker Machine to point to digital-ocean machine
  • dk ps etc.
  • docker-compose up
  • profit

Glossary of common commands

Docker Machine

  • docker-machine ls: get info on all machines available to Docker Machine
  • docker-machine build --driver <driver-name> <options> <machine-name>: create new host machine available to Docker Machine
  • docker-machine env <machine-name>: get info on how to point Docker Machine at <machine-name>
  • dkme <machine-name>, if intalled: point Docker Machine at <machine-name>

Docker client

  • docker ps: show all running containers on this machine

  • docker ps -a: show all containers on this machine running or not

  • docker ps -aq: show all ids for containers on this machine running or not

  • docker images: show all images on this machine

  • docker rmi <image-name>: remove <image-name> from machine

  • docker stop <container-name>: stop running <container-name>

  • docker rm <container-name>: destroy <container-name>

  • docker rm -f <container-name>: stop and destroy <container-name>

  • docker rm -f $(docker ps -aq): stop and destroy all containers on this machine

  • dkrm, if installed, alias for docker rm -f $(docker ps -aq)

  • docker run [<options>] <image-name> [<command>]: run a container from <image-name> [with <command>]

Options include: - --name: give the container a name - --rm: destroy the container as soon as it stops running - -d: run the container as a background process, or daemon - -it: run the container interactively, running from its command line.This must be used in conjunction with the <command> bash, e.g., docker run -it node bash - -p <host-port>:<container-port>: map the exposed <container-port> to <host-port> - --link <container-to-link-to>:<alias-for-linked-container>: Create environmental variable linking to <container-to-link-to

  • docker exec <container-name> <command-name>: execute <command-name> on running <container-name>
  • docker exec -it <container-name> bash: go to command line of running <container-name>

Docker Compose

  • docker-compose up: run in directory with docker-compose.yml to launch fleet of containers based on configuration in yml file