Skip to content

Latest commit

 

History

History
97 lines (75 loc) · 3.29 KB

README.md

File metadata and controls

97 lines (75 loc) · 3.29 KB

GKE Example

This project is a demo of how we could write a dockerised micro-service using nodejs to run on Google Cloud Platform (GCP).

Pub/Sub

This application receives messages via subscriptions to Google pub/sub topics rather than HTTP requests. The build and deployment model should also work for an HTTP-based micro-service using express or koa, but that is untested.

Local Development

  • You will need to download a key for connecting to the pub/sub topic. This can be done in the api management console for GCP.
  • Put the key in this project's root folder and name it keyfile.json. This could potentially be tidied up to use environmental variables instead.
  • The application can be run as a normal node application using npm start.
  • Once the application starts up, it will make a connection to pub/sub to setup a subscription. Messages are passed to a stub rest client that merely prints out the incoming message.

Manual Deployment

Make sure you have the latest version of the command line tools available:

brew install Caskroom/cask/google-cloud-sdk
gcloud components install kubectl

Alias kubectl for your sanity:

alias kubectl="/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/bin/kubectl"

Google don't currently support running arbitrary nodejs applications using App Engine (their platform-as-a-service offering). Instead, we produce a Docker image which can run on Google Container Engine (referred to as GKE to distinguish it from Google Compute Engine). The following commands can either be run on a local laptop, CI environment or a developer's laptop.

First, login to your Google account with the newly install SDK. This will launch a web browser for a normal OAuth 2 flow:

gcloud auth application-default login

Build the docker image with a prefix of the GCP region, followed by the project name. Label it with a version string:

docker build -t eu.gcr.io/integrations-154709/example-image:1.3 .

Then push that labelled image to the Google-hosted docker image registry:

gcloud docker -- push eu.gcr.io/integrations-154709/example-image:1.3

Connect to the currently running kubernetes cluster (named cluster-1) in our test project:

gcloud container clusters get-credentials cluster-1 --zone europe-west1-b --project integrations-154709

Rollout the new image for our deployment named deployment/example-image:

kubectl set image deployment/example-image example-image=eu.gcr.io/integrations-154709/example-image:1.3

List our pods in the deployment to check everything is running nicely:

kubectl get pods

You should see something like:

NAME                             READY     STATUS    RESTARTS   AGE
example-image-2448862826-1n9aj   1/1       Running   0          19m

Try looking at the console of this running container with:

kubectl attach example-image-2448862826-1n9aj -c example-image

When you publish a message on the pub/sub topic, you should see it printed to the console of the container running on Google's infrastructure, displayed on your laptop.

Scale a Deployment

See how many pods are in your deployment currently:

kubectl get deployments

Scale the deployment:

kubectl scale deployment/example-image --replicas=2

See the status of the individual pods:

kubectl get pods