Private Beta - Scalingo Docker Image Addon


Thanks to this addon, you’ll be able to get back the Docker Images that have been built when deploying your application in our infrastructure.

Everytime you push code to Scalingo, a build is triggered resulting in the construction of a Docker Image. When this build phase is successful we try to deploy this Docker Image by trying to run it on our cloud. This addon lets you download every Docker Image that has been built by Scalingo.

Use cases

Because the docker image is the exact same one we’re running in our cloud, you can use it to debug your production code or as a pledge of reversibility.

You can also use Scalingo as a Docker Integration Platform. You push your code from one side and get a generic Docker Image on the other. You can then use Scalingo for your staging environments and run the final Docker image on your own private cloud or the one from your customers. It’s especially useful when your customers ask to run your application in their own environments for various reasons (Big Co wanting to controll their infrastructure, legal reasons like in the MedTech world for instance).

Setup of the addon

Provision the add for your application from our web dashboard or with our CLI:

$ scalingo addons-add scalingo-docker-image base-plan

Usage of the addon

Once this is done, has been added, the deployments panel of your app dashboard will change, a Docker logo will be present. Click on it to get the instructions to download the image of a given deployment.

Login to your application registry

$ docker login
Username: <scalingo username>
Password: <scalingo API key>
Email:    <scalingo email>

The API key is available on your profile, copy it from there.

Download your image

$ docker pull
0123456789abcdef: Pulling from app-myappname
6599cadaf950: Downloading 59.99 MB/65.69 MB
23eda618d451: Download complete 
f0be3084efe9: Download complete 
52de432f084b: Download complete 
a3ed95caeb02: Download complete 
b11499e07372: Download complete 
40d9c9cec188: Download complete 
b7c87d00e3ba: Downloading 31.84 MB/362.9 MB
9aac245cd453: Downloading 23.74 MB/60.04 MB
f1ac1758a0cb: Waiting 

Run your app

The entrypoint of the image is a script located at /start. Its usage is:

/start <container type>

# Example, start the web (default) process
/start web

The compelete docker command to start your app on port 4000 looks like the following:

docker run -it \
  -e PORT=4000
  -p 4000:4000 \ /start web

In this case no environment variable has been set, you need to add the environment variables required by your app by adding multiple -e flags:

docker run -it \
  -e PORT=4000 \
  -e RAILS_ENV=production \
  -e RACK_ENV=production \
  -e DATABASE_URL=postgres:// \
  -e MAIL_URL=smtp:// \
  -p 4000:4000 \ /start web

We’re using as DATABASE_URL host because in a container, your computer will be reachable at this IP.

That’s it, your app is running with your environment.

schedule 30 May 2016