Containerized Ruby on Rails App Delivery on GCP
This example is a full end to end example of delivering a containerized Ruby on Rails application. It
- Provisions a Google Kubernetes Engine (GKE) cluster
- Provisions a fully managed Google Cloud SQL PostgreSQL database
- Builds a containerized Ruby on Rails container image, and publishes it to Docker Hub
- Deploys that container image as a Kubernetes Service inside of the provisioned GKE cluster
All of these happen behind a single
pulumi up command, and are expressed in just a handful of TypeScript.
Ensure you have downloaded and installed the Pulumi CLI. Ensure you have downloaded and installed Docker We will be deploying to Google Cloud Platform (GCP), so you will need an account. If you don’t have an account, sign up for free here. In either case, follow the instructions here to connect Pulumi to your GCP account.
This example assumes that you have GCP’s
gcloud CLI on your path. This is installed as part of the
Running the Example
After cloning this repo,
cd infra/ and run these commands. After 8 minutes, you’ll have a fully functioning GKE
cluster and containerized Ruby on Rails application deployed into it, using a hosted PostgreSQL instance!
Create a new stack, which is an isolated deployment target for this example:
$ pulumi stack init gcp-rails-dev
Set the required configuration variables for this program:
$ pulumi config set gcp:project [your-gcp-project-here] $ pulumi config set gcp:zone us-west1-a # any valid GCP zone works $ pulumi config set clusterPassword --secret [your-new-cluster-password-here] # must be at least 16 characters $ pulumi config set dbUsername [your-new-db-username-here] $ pulumi config set dbPassword --secret [your-new-db-password-here] $ pulumi config set dockerUsername [your-dockerhub-username-here] $ pulumi config set dockerPassword --secret [your-dockerhub-password-here] $ pulumi config set masterVersion # any valid master version, or latest
Config variables that use the
--secretflag are encrypted and not stored as plaintext.
By default, your cluster will have 3 nodes of type
n1-standard-1. This is configurable, however; for instance if we’d like to choose 5 nodes of type
n1-standard-2instead, we can run these commands:
$ pulumi config set clusterNodeCount 5 $ pulumi config set clusterNodeMachineType n1-standard-2
This shows how stacks can be configurable in useful ways. You can even change these after provisioning.
Deploy everything with the
pulumi upcommand. This provisions all the GCP resources necessary, including your GKE cluster and database, as well as building and publishing your container image, all in a single gesture:
$ pulumi up
This will show you a preview, ask for confirmation, and then chug away at provisioning your cluster:
Updating stack 'gcp-rails' Performing changes: Type Name Status Info + pulumi:pulumi:Stack gcp-rails-gcp-rails-dev created + ├─ docker:image:Image rails-app created 40 messages + ├─ gcp:container:Cluster gke-cluster created + ├─ gcp:sql:DatabaseInstance web-db created + ├─ pulumi:providers:kubernetes gke-k8s created + ├─ gcp:sql:User web-db-user created + ├─ kubernetes:apps:Deployment rails-deployment created + └─ kubernetes:core:Service rails-service created Diagnostics: docker:image:Image (rails-app): Building container image: context=../app logging in to registry... Sending build context to Docker daemon 22.79MB Step 1/9 : FROM ruby:2.5 ---> 8e2b5b80415f Step 2/9 : RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs ---> Using cache ... ---outputs:--- appAddress: "http://184.108.40.206:3000" appName : "rails-deployment-vt7uyigk" dbAddress : "220.127.116.11" kubeConfig: "apiVersion: v1\n..." info: 8 changes + 8 created Update duration: 7m20.867501974as
After this completes, numerous outputs will show up.
appAddressis the URL that your Rails app will be available at,
appNameis the resulting Kubernetes Deployment,
dbAddressis your PostgreSQL hostname in case you want to connect to it with
kueConfigis the full Kubernetes configuration that you can use with
Open a browser to visit the site,
open $(pulumi stack output appAddress)/todo_lists. Make some todo lists!
At this point, you have a running cluster. Feel free to modify your program, and run
pulumi upto redeploy changes. The Pulumi CLI automatically detects what has changed and makes the minimal edits necessary to accomplish these changes. This could be altering the app code, adding new GCP or Kubernetes resources, or anything, really.
Once you are done, you can destroy all of the resources, and the stack:
$ pulumi destroy $ pulumi stack rm