Updating services

  • We want to make changes to the web UI

  • The process is as follows:

    • edit code

    • build new image

    • ship new image

    • run new image

Updating a single service the hard way

  • To update a single service, we could do the following:

    REGISTRY=localhost:5000 TAG=v0.3
    docker build -t $IMAGE webui/
    docker push $IMAGE
    docker service update dockercoins_webui --image $IMAGE
  • Make sure to tag properly your images: update the TAG at each iteration

    (When you check which images are running, you want these tags to be uniquely identifiable)

Updating services the easy way

  • With the Compose integration, all we have to do is:

    export TAG=v0.3
    docker-compose -f composefile.yml build
    docker-compose -f composefile.yml push
    docker stack deploy -c composefile.yml nameofstack
  • That's exactly what we used earlier to deploy the app

  • We don't need to learn new commands!

Changing the code

  • Let's make the numbers on the Y axis bigger!
  • Edit the file webui/files/index.html:

    vi dockercoins/webui/files/index.html
  • Locate the font-size CSS attribute and increase it (at least double it)

  • Save and exit

Build, ship, and run our changes

  • Four steps:

    1. Set (and export!) the TAG environment variable
    2. docker-compose build
    3. docker-compose push
    4. docker stack deploy
  • Build, ship, and run:
    export TAG=v0.3
    docker-compose -f dockercoins.yml build
    docker-compose -f dockercoins.yml push
    docker stack deploy -c dockercoins.yml dockercoins

Viewing our changes

  • Wait at least 10 seconds (for the new version to be deployed)

  • Then reload the web UI

  • Or just mash "reload" frantically

  • ... Eventually the legend on the left will be bigger!