play-with-docker

Play With Docker gives you the experience of having a free Alpine Linux Virtual Machine in the cloud where you can build and run Docker containers and even create clusters with Docker features like Swarm Mode.

Under the hood DIND or Docker-in-Docker is used to give the effect of multiple VMs/PCs.

There are 3 main services of the stack:

• HaProxy - This will route the traffic to the richt container
• PWD - This is the 'main' engine as this serves the viewer and you use it to start the instances
• l2 - A routing container. This is used for exposing external services to route it to the right container.

A live version is available at: http://play-with-docker.com/

Notes:

• There is a hard-coded limit to 5 Docker playgrounds per session. After 4 hours sessions are deleted on the live hosted site. On Self hosted sites, expiration can be configurable.
• Only http, https, websocket and SSH connections are allowed.
• If you want to override the DIND version or image then set the environmental variable i.e. DIND_IMAGE=franela/docker<version>-rc:dind. Take into account that you can't use standard dind images, only franela ones work.

Getting Started With Self Hosted Version

On Mac or Windows

Software Requirements

• Docker 18.06.0+
• franela dind
• A modern browser like Chrome, Firefox, Safari
• dnsmasq on Mac
• git bash On Windows or any terminal on Mac for starting up docker compose

Steps for Starting Up PWD (On Mac and Windows 10)

• Initialize docker swarm and then clone the git repo and start the Play With Docker stack with docker compose.

  # Verify the Docker daemon is running else restart docker engine or docker desktop 
  docker run hello-world
  
  # Ensure Docker daemon is running in swarm mode
  docker swarm init
  
  # Clone this forked git repo or the main git repo
  git clone https://github.com/play-with-docker/play-with-docker
  cd play-with-docker
  
  # Get the latest franela/dind image
  docker pull franela/dind
  
  # Start PWD as a container
  docker-compose up -d
  
  

• Now navigate to http://localhost and click the green "Start" button to create a new session, followed by "ADD NEW INSTANCE" to launch a new terminal instance or choose any of the predefined templates to quickly launch the sessions.

• If you deploy any service and you need to browse it, please open the appropriate port from the session and browse it.

On Linux

Requirements for Linux

• Docker 18.06.0+
• Go (stable release)
• franela dind
• A modern browser like Chrome, Firefox, Safari

Steps for Starting Up PWD on Linux

• Initialize docker swarm and then clone the git repo and start the PWD stack with docker compose

  # Verify the Docker daemon is running else restart docker engine or docker desktop 
  docker run hello-world
  
  # Load the IPVS kernel module. Because swarms are created in dind,
  # the daemon won't load it automatically
  sudo modprobe xt_ipvs
  
  # Ensure Docker daemon is running in swarm mode
  docker swarm init
  
  # Clone this forked git repo or the main git repo
  git clone https://github.com/play-with-docker/play-with-docker
  cd play-with-docker
  
  # Get the latest franela/dind image
  docker pull franela/dind
  
  # Optional (with go1.14): pre-fetch module requirements into vendor
  # so that no network requests are required within the containers.
  # The module cache is retained in the pwd and l2 containers so the
  # download is a one-off if you omit this step.
  go mod vendor
  
  # Start PWD as a container
  docker-compose up -d
  
  

• Now navigate to http://localhost and click the green "Start" button to create a new session, followed by "ADD NEW INSTANCE" to launch a new terminal instance or choose any of the predefined templates to quickly launch the sessions.

• If you deploy any service and you need to browse it, please open the appropriate port from the session and browse it.

Port Forwarding:

• On Mac:

  • In order for port forwarding to work correctly in development/local machine you need to make *.localhost to resolve to 127.0.0.1.

  • That way when you try to access to pwd10-0-0-1-8080.host1.localhost, then you're forwarded correctly to your local PWD server.

  • You can achieve this by setting up a dnsmasq server (you can run it in a docker container also) and adding the following configuration(for detailed steps for implementing in Mac refer here:

    address=/localhost/127.0.0.1
    

  • Don't forget to change your computer default DNS to use the dnsmasq server to resolve.

• On Windows10:
  • Generally port forwarding on browser will work fine, but for SSH instead of @direct.localhost just use @127.0.0.1

FAQ

How can I connect to a published port from the outside world?

If you need to access your services from outside, use the following URL pattern http://ip<hyphen-ip>-<session_jd>-<port>.direct.labs.play-with-docker.com (i.e: http://ip-2-135-3-b8ir6vbg5vr00095iil0-8080.direct.labs.play-with-docker.com).

Why is PWD running in ports 80 and 443?, Can I change that?.

No, it needs to run on those ports for DNS resolve to work. Ideas or suggestions about how to improve this are welcome

How can I SSH into a running host ?

• Generate an SSH Key Pair(if not already existing). e.g. on Linux or Mac or Windows 10(with git bash), run ssh-keygen and fill out name of the ssh key file and empty passphrase for passwordless authentication.
• Connect to the target docker host as follows: Run ssh -i . Example: ssh -i ida_rsa ip172-18-0-9-bfe8s7iv9dig00cuhdsg@direct.labs.play-with-docker.com
• Note: For Hosted Instances, SSH Port is 22, For Self Hosted instance started from the compose file, by default it is mapped to 8022
  • e.g. ssh -p 8022 [email protected] on Mac with dnsmasq or else without it or on Windows 10 e.g. ssh -p 8022 [email protected]