Learning Appfile Step by Step

Learning Appfile Step by Step

Appfile is the main user interface to configure application deployment on Vela.

In this tutorial, we will build and deploy an example NodeJS app under examples/testapp/.

Prerequisites

Docker installed on the host
KubeVela installed and configured

1. Download test app code

git clone and go to the testapp directory:

$ git clone https://github.com/oam-dev/kubevela.git
$ cd kubevela/docs/examples/testapp

The example contains NodeJS app code, Dockerfile to build the app.

2. Deploy app in one command

In the directory there is a vela.yaml which follows Appfile format supported by Vela. We are going to use it to build and deploy the app.

NOTE: please change oamdev to your own registry account so you can push. Or, you could try the alternative approach in Local testing without pushing image remotely section.

    image: oamdev/testapp:v1 # change this to your image

Run the following command:

$ vela up
Parsing vela.yaml ...
Loading templates ...
Building service (express-server)...
Sending build context to Docker daemon  71.68kB
Step 1/10 : FROM mhart/alpine-node:12
 ---> 9d88359808c3
...
pushing image (oamdev/testapp:v1)...
...
Rendering configs for service (express-server)...
Writing deploy config to (.vela/deploy.yaml)
Applying deploy configs ...
Checking if app has been deployed...
App has not been deployed, creating a new deployment...
✅ App has been deployed 🚀🚀🚀
    Port forward: vela port-forward testapp
             SSH: vela exec testapp
         Logging: vela logs testapp
      App status: vela status testapp
  Service status: vela status testapp --svc express-server

Check the status of the service:

$ vela status testapp
  About:
    Name:       testapp
    Namespace:  default
    Created at: 2020-11-02 11:08:32.138484 +0800 CST
    Updated at: 2020-11-02 11:08:32.138485 +0800 CST
  Services:
    - Name: express-server
      Type: webservice
      HEALTHY Ready: 1/1
      Last Deployment:
        Created at: 2020-11-02 11:08:33 +0800 CST
        Updated at: 2020-11-02T11:08:32+08:00
      Routes:

Alternative: Local testing without pushing image remotely

If you have local kind cluster running, you may try the local push option. No remote container registry is needed in this case.

Add local option to build:

    build:
      # push image into local kind cluster without remote transfer
      push:
        local: kind
      docker:
        file: Dockerfile
        context: .

Then deploy the app to kind:

$ vela up

(Advanced) Check rendered manifests

By default, Vela renders the final manifests in .vela/deploy.yaml:

apiVersion: core.oam.dev/v1alpha2
kind: ApplicationConfiguration
metadata:
  name: testapp
  namespace: default
spec:
  components:
  - componentName: express-server
---
apiVersion: core.oam.dev/v1alpha2
kind: Component
metadata:
  name: express-server
  namespace: default
spec:
  workload:
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: express-server
    ...
---
apiVersion: core.oam.dev/v1alpha2
kind: HealthScope
metadata:
  name: testapp-default-health
  namespace: default
spec:
  ...

[Optional] Configure another workload type

By now we have deployed a Web Service, which is the default workload type in KubeVela. We can also add another service of Task type in the same app:

services:
  pi:
    type: task
    image: perl 
    cmd: ["perl",  "-Mbignum=bpi", "-wle", "print bpi(2000)"]
  express-server:
    ...

Then deploy Appfile again to update the application:

$ vela up

Interested in the more details of Appfile? Learn Full Schema of Appfile

What’s Next?

Congratulations! You have just deployed an app using Vela.

Some tips that you can have more play with your app: