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Docker with Docker Toolbox for Windows Tutorial

This tutorial walks you through the basics of using a Java app server (WildFly) via a Linux container, running on Windows with Docker Toolbox. We have been testing this tutorial on Windows 7 and 8.1, you will notice that the screenshots come from either of those versions as this document has been tested and maintained.

There are notes for people running on Macs as well.

First follow installation steps for Docker Toolbox:

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Install all the components.

Mac: The docker binaries are in /usr/local/bin which you can access from your terminal.

Windows: The docker binaries lands in C:\Program Files\Docker Toolbox for Windows


Tip 1: Where does the boot2docker VM ISO land on a Windows?

Windows: C:\Users\<your_username>\.docker\machine\cache\boot2docker.iso

Mac: ~/.docker/machine/cache/boot2docker.iso


Tip 2: Where does the docker-machine default instance land on Windows installation of VirtualBox?

C:\Users\<your_username>\.docker\machine\machines\default\default


Tip 3: Window Size Width 160 - docker ps is best displayed with lots of width.

You can make this change on the Docker Quickstart Terminal command window as well

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Tip 4: VirtualBox before any docker-machyine instance.

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VirtualBox installed prior to Docker Toolbox has no mention of any docker-machine until we create any docker-machine host. Also, if you have previously installed Docker Toolbox, you can often use docker-machine upgrade <docker host name> to simply update to the latest version.


Explore Docker

  1. Look for and select the Docker Quickstart Terminal menu option in your Start Menu

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    Or use start.sh to launch the command prompt (not the normal Windows command prompt)

    You should be able to double-click on start.sh in C:\Program Files\Docker Toolbox

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    If you successfully launch start.sh, it will execute up, status and ip, therefore you can skip to step 8 below. Do make note of the IP address that is printed out, you will need it later.

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  2. You might also execute docker-machine commands from the Windows (DOS) Command Prompt aka "cmd.exe" and type

    docker-machine version

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  3. docker-machine.exe create -d virtualbox default Alt text

    You should see the docker host called default listed in VirtualBox Manager

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  4. docker-machine status default

    Note: When it is time to shutdown, run docker-machine stop default

  5. docker-machine env default Alt text

    This will show all environments variables needed to connect to the docker-machine host called default

  6. docker-machine env --shell cmd default

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    Alternatively you can specify which type of shell you are using. So the proper instructions for environments variables will be created.

  7. docker-machine ssh default Alt text

    From this point forward, you will be inside of a Linux shell, using Linux commands

  8. docker version

  9. docker info Alt text

  10. docker Alt text

  11. docker images

  12. docker ps -a Alt text

  13. docker run centos /bin/echo "Hello World"

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    This will take some time if this is the first run of the "centos" image (size: 200 MB).

    If you run the same command again, you will notice that is runs immediately, no download required. A Docker container starts incredibly fast when compared to traditional virtual machine technology.

    To prove that point, run the same command again.

    Note: the container stops as soon as it finishes the /bin/echo command

  14. On Windows, with docker-machine, the Users directory is shared as /c/Users

    On Mac the Users directory is shared as /Users

    ls /c/Users

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    This shared folder will allow you to add and edit files using your traditional Windows tools instead of having to learn vi or nano.

    Using your File Explorer, create a demo sub-directory to your home directory and then use a ls -l to see it via the boot2docker-vm (in this example Burr is the username):

    ls -l /c/Users/<your_username>/demo

    Mac: ls -l /Users/<your_username>/demo

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    In this screenshot, I already some sample projects in my C:\Users\Burr\demo directory

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    Note: We won't be using "demo" in this tutorial, the goal here was to let you see the connection between /c/Users and C:\Users

  15. docker run -i -t centos /bin/bash

    -i means interactive and
    -t allows your keyboard input
    

    You can also use -it as well as -i -t. Remember this trick - if you have an app server failing to start, you can see the console output and review the logs by using "-it"

    If this is your first time running the centos image, it may take over a minute to download.

    You are now running inside of the Centos-based container, to prove that point, use the following command

    cat /etc/system-release

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    Type exit to leave the container and drop back into the boot2docker-vm shell.

  16. docker ps

    There should be no currently running containers since exit terminated the last centos container Alt text

  17. docker ps -a

    but there have been previously run containers

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  18. docker images

    shows local images Alt text

  19. docker pull centos/wildfly

    Docker Hub contains a large number of pre-configured images that are ready to use via a simple "pull" e.g. https://registry.hub.docker.com/u/centos/wildfly/

    run does an implicit "pull" if the image is not already downloaded

    Docker images are typically identified by two words "owner"/"imagename" The centos/wildfly image includes nice documentation on how to use it - we will be following several of those steps next.

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  20. docker run -it centos/wildfly

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    The t is important so you can Ctrl-C to stop wildfly and the container.

    Hit Ctrl-C and run a docker ps to see that the container has been stopped.

    In this particular case, the WildFly instance does not expose any ports to the outside world, so we don't have any access to WilFly. let's try enabling external access next.

  21. docker run -it -p 8080:8080 centos/wildfly

    The -p <host_port>:<container_port> flag exposes the container port to the docker host machine default. The first port 8080relates to the docker host machine port, and the second parameter 8080 port relates to the container port that will be exposed.

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    Each docker container process runs inside the docker host called default created by docker-machine previously. To get the ip of the docker host, just open another CMD.exe terminal and type docker-machine ip default.

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    Press Ctrl-C to terminate the WildFly container.

  22. docker history centos/wildfly

    The history command allows you to see more detail into how the image was crafted Alt text

Modify the image and provide our own custom Java application

  1. If you remember way back to ls /c/Users/<your_username>/demo, the Users directory on your Windows host is shared with the docker default host (thanks to VirtualBox Guest Additions). In your home directory, create a directory called docker_projects that is a sibling of demo. You can create the directory from within the docker-machine host default with the following command (or just use File Explorer).

    mkdir /c/Users/<your_username>/docker_projects
    

    Use your home directory name in place of "Burr"

    and then create a sub-directory called myapp

    mkdir /c/Users/<your_username>/docker_projects/myapp
    

    You can create the "myapp" directory via Windows Explorer or the boot2docker-vm shell

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    and then change to the directory, it is important that you do this inside of the boot2docker-vm shell

    cd /c/Users/<your_username>/docker_projects/myapp
    
  2. In the myapp directory, create a text file called Dockerfile, with no extension.

    On Windows you might use the Atom editor from Atom.io for text editing.

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  3. Edit the newly created Dockerfile and add the following two lines:

    FROM centos/wildfly
    
    COPY javaee6angularjs.war /opt/wildfly/standalone/deployments/
    

    Note: On Macs, we have seen Wildfly have a permissions problem with the .war. The workaround is to switch to Root and use chown to make the ajustment to the .war file by adding the following two lines:

    USER root
    RUN chown wildfly:wildfly /opt/wildfly/standalone/deployments/javaee6angularjs.war
    

    The trailing "/" does matter

    You can find javaee6angularjs.war at https://github.com/burrsutter/docker_tutorial/blob/master/javaee6angularjs.war?raw=true Download the war and copy it to the myapp directory.

  4. Back in the boot2docker ssh session

    docker build --tag=myapp .
    

    the trailing "." is important

    Use the docker docker images command to see if the image was created

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  5. Let's see if that worked

    docker run -it -p 8080:8080 myapp
    

    you should see the deployment of javaee6angularjs.war in the wildfly console logging

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  6. And test the app via your browser http://192.168.99.100:8080/javaee6angularjs

    The IP address in my screenshots change from time to time as this document has been maintained. Just make sure to remember YOUR IP address as seen via docker-machine ip default

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    Now it is time for a victory dance around the room! You have your first Java EE application deployed as part of a Docker container. Remember, Ctrl-C to shut down the app server.

Extra Credit

  1. Run detached

    You could also use a -d instead of -it to run the container detached, in the background

    docker run -d -p 8080:8080 myapp
    

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    If detached, you will need to use docker ps to see the active containers and then use docker stop CONTAINER_ID and docker rm CONTAINER_ID

    Note: Docker automatically generated the name "agitated_hawking" which you can use instead of the CONTAINER_ID. Each time that you execute docker run command, it will create a different (and funny) name for your container.

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  2. Container naming

    Adding a --name=some_name allows you to give override the default name of agitated_hawking or whatever was randomly assigned to your container by Docker

    docker run --name=myapp_is_running -d -p 8080:8080 myapp
    

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  3. Viewing logs

    docker logs myapp_is_running
    

    and you can docker stop myapp_is_running when it is time to shutdown the -d detached app server container

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  4. Dive into a live container

    docker exec -it myapp_is_running bash
    
    cd /opt/wildfly/standalone/log
    tail server.log
    

    This is a very useful technique if you find things are misbehaving and you wish poke around inside the running container.

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Cleanup

OPTIONAL - Clean Slate: If you wish to completely clean up and run through the above steps again:

  1. Remove/Delete all containers

    docker rm `docker ps -a -q`
    

    the back ticks are important! You might also need to "stop" or "kill" any containers that are running and will not remove.

    docker ps -a
    docker stop CONTAINER_ID
    docker kill CONTAINER_ID
    

    Replace CONTAINER_ID with the id seen in the docker ps results.

  2. Remove/Delete all images

    docker rmi `docker images -a -q`
    

    watch those back ticks again

    You will probably see some scary error messages. You can ignore it since it's caused because there's dependencies between certain docker images. This bulk command doesn't follow the dependencies order.

Check out the follow-on tutorial for adding MySQL. https://github.com/burrsutter/docker_mysql_tutorial

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