https://github.com/wsargent/docker-cheat-sheet

• Getting terminal access

docker exec -it [container ID] /bin/bash

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Install Docker

Docker on Mac using docker-machine

• install Docker Toolbox first
• After that, install a VM with Docker Machine using VirtualBox:

docker-machine create --driver=virtualbox default
docker-machine ls
eval "$(docker-machine env default)"

• we can set docker-machine's env variable along the way:

docker-machine create -d virtualbox
-engine-env HTTP_PROXY=
-engine-env HTTPS_PROXY=
default

• add user to docker sudo user group

sudo usermod -aG docker my_account

Docker for Mac vs docker-machine (from Docker Toolbox)

You can use Docker for Mac and Docker Toolbox together on the same machine.

• When you want to use Docker for Mac, make sure all DOCKER environment variables are unset. You can do this in bash with unset ${!DOCKER_*}.
• When you want to use one of the VirtualBox VMs you have set with docker-machine, just run aeval $(docker-machine env default) (or the name of the machine you want to target). This will switch the current command shell to talk to the specified Toolbox machine.

Docker on Linux

(based on AWS ECS docker basic intro)

sudo yum update -y
sudo yum install -y docker
sudo service docker start
sudo usermod -aG docker ec2-user # add ec2-user to docker group. Logout and login again after this.
docker info # verify docker command can run without sudo

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Docker-machine

• use to provision docker host
• creating a host
  • use docker-machine create command and specify the driver to use
  • driver: virtualbox / AWS / VMWare / digital ocean ...

docker-machine create --driver virtualbox testhost

• Provision hosts in the cloud:

  • Each cloud provider has different options for docker-machine create

• Docker machine SSH

  • login using the SSH key that is created when creating the machine

docker-machine ssh host-name

docker-machine ls

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Container

Create and run a container

docker [start | stop] container_name

docker run -it --name container_name image_name command
docker run [option] [image] [command] [args]
docker run ubuntu:14.04 echo "hello world"
docker run ubuntu:14.04 ps aux

create and start container, run comand, destroy container

docker run --rm -it image_name command

Run container with a terminal

docker run -it ubuntu:12.04 /bin/bash
-i: connect docker to the STDIN on the container
-t: run a terminal
the following command must be a terminal
in this way, if you exit the container, you also shutdown the container, as the bash process is the first process run in the container
Use Ctrl + P + Q to exit and prevent shutdown container

Run container in detached mode

docker run -d ubuntu:12.04 ping 127.0.0.1 -c 50

observe the log using

docker logs [container_id]
docker logs -f [container_id]

docker -e TEST_VAR=test ubuntu:12.04

add environment variable

docker inspect container_id

Other

docker run -d -P nginx

docker run -it --rm -p 8080:8080 -v /path/to/agent.jar:/agent.jar -e JAVA_OPTS='-javaagent:/agent.jar' tomcat:8.0.29-jre8

docker ps
docker ps -a # included stopped container

Additional:

• entry point?

Container troubleshoot

docker logs <container name>
docker logs -f <container name>

• map a host folder to application's log folder in the container (use Volume)

docker run -d -P -v /nginxlogs:/var/log/nginx nginx # host_dir:container_dir

docker inspect
docker inspect --format

Start and stop docker deamon ????

sudo service docker stop
sudo service docker start
sudo service docker restart

• start the docker deamon

sudo docker -d &

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Image

• list images:

docker images

• download new image:

docker pull image_name

Dockerfile

FROM ubuntu:12.04

# Install dependencies
RUN apt-get update -y
RUN apt-get install -y git curl apache2 php5 libapache2-mod-php5 php5-mcrypt php5-mysql

# Install app
RUN rm -rf /var/www/*
ADD src /var/www

# Configure apache
RUN a2enmod rewrite
RUN chown -R www-data:www-data /var/www
ENV APACHE_RUN_USER www-data
ENV APACHE_RUN_GROUP www-data
ENV APACHE_LOG_DIR /var/log/apache2

EXPOSE 80

CMD ["/usr/sbin/apache2", "-D",  "FOREGROUND"]

docker build -t my-dockerhub-username/amazon-ecs-sample .
docker images # verify it exists

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Network

• The -p 80:80 option maps the exposed port 80 on the container to port 80 on the host system.

docker run -p 80:80 image_name

• Find Docker ip address

boot2docker ip

• If using docker-machine

docker-machine ip machine_name

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Registry and Repository

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Dockerfile

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Volumes

http://crosbymichael.com/advanced-docker-volumes.html

Attach volumes

docker volume create
docker volume rm

docker volume ls
docker volume inspect

Map MacOS host directories as docker volumes:

docker run -v /Users/wsargent/myapp/src:/src

Save logs