Deploying to Google App Engine¶

Step One: Install Google Cloud SDK¶

Step one to any Google App Engine project is to install the Google Cloud SDK.

The installation can be found here:

https://cloud.google.com/sdk/docs/

Step Two: Start a Project and Enable Billing¶

The second step is to actually create a project and set up your billing information on it.

To create a project:

https://console.cloud.google.com/project

After creating your project, you’ll want to take down the Project ID. We will need this for several upcoming steps.

To enable billing:

https://support.google.com/cloud/answer/6293499#enable-billing

Step Three: Define app.yaml¶

The magic of the Google App Engine comes in the app.yaml file that it uses to set up and configure your environment. Google’s documentation is a little confused on what is and isn’t allowed in the app.yaml file for a NodeJS application. For example, that document says that the login setting is not allowed for NodeJS apps, but we successfully deployed with it.

Our app.yaml file looks like this:

# configuration file for GAE with NodeJS
#

runtime: nodejs
vm: true
threadsafe: true
service: kvasir

vm_health_check:
    enable_health_check: False

handlers:
 - url: /.*
   script: server.js
   secure: always
   login: admin

In this file, we tell the GAE that we want to use nodejs, and we are using a flexible environment (vm: true). We also specify a service name. The GAE readily supports a microservice architecture which we can use to our advantage. Even if this is the only service deployed on your application, that’s fine. Giving it a name makes future updates easier.

Under the handlers section we tell the GAE where to send relevant traffic. We want all traffic to go to our server.js server, and all requests should be done with HTTPS and all requests need to have a login associated with them.

The login component here is key. There are a few different login options but login: admin means that only people registered with your application are allowed entry. This allows you to setup authentication with Google outside of Kvasir. All users who enter the application are first vetted by the GAE and only authorized users are allowed entrance into the actual application.

You can tweak and add more settings to your application as you see fit.

Step Four: Add Users¶

You can invite users using their Google emails under the IAM & Admin section in your app’s console.

In order for them to be considered admin they only need to have Viewer privileges. You do not need to make everyone who needs access to Kvasir an owner of the entire GAE project. This allows you to maintain access control over the workings of the GAE project but still give everyone access to Kvasir.

Step Five: Deploy¶

Deploying the application can be a little messy, but the general idea with Docker containers is that, if it runs in your local environment, it should run just fine in the deployed environment.

The main issues we had with deploying were with the package.json file. Some of our packages had been installed locally but were not contained in the package.json file, so not all packages were installed and the application could not start.

To deploy the application, you must run the following command from the root directory of Kvasir:

>>> gcloud app deploy --project=<YOUR_PROJECT_NAME>

After deploying, you will see a lot of text on your screen as the Docker container downloads its environment and installs the application. Deploying took us anywhere from 5-10 minutes. Once the console says that deployment is done, you can go to the link for your project and you should be live!

Can’t set up login with NodeJS¶

We were very excited about the opportunity to wrap Kvasir in an authentication system without having to implement one ourselves. However, we may have unknowingly uncovered a bug/hack with the Google App Engine that you may not uncover on your first deployment. We already had an existing GAE project set up that was running a Python application, so we added Kvasir as a service on that same project.

If deploying Kvasir fails because the GAE does not recognize (or does not want to recognize) the login option and value in your app.yaml, you can reproduce our hack. All you have to do is deploy a service with one of the supported languages (Python, PHP, Go, or Java) under the same project. That should provide you with all the access you need. The application does not have to provide any functionality. It can even be a simple URL handler that immediately redirects to the NodeJS service, or be one of the tutorial apps that GAE provides. This will give you a fully supported application with the NodeJS service running underneath it.

Docker Container Dies during Deployment¶

There is a lot more logging that the GAE does outside of what you see on the console during deployment. Going to the Logging section on your apps console will give you a better idea of where your container is dying.

One of the most annoying parts about GAE and Docker containers is the container will keep trying to start even if it’s never going to work. You can stop the instance from the app’s console, or redeploy the application with the same version name.

During development, the reason that our Docker container died was most commonly related to a bad package.json file. Since that file comes with Kvasir, you shouldn’t have any issues. If you are experiencing issues, then check the logs to see if there is something amiss in your app.yaml file that’s causing it to die.