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Version: 3.0.0 (Alpha 2) 🚧

Quickstart Guide

In this guide, we will be using odo to create a "Hello World" application.

You have the option of choosing from the following frameworks for the quickstart guide:

  • Node.js
  • .NET
  • Java (Spring Boot)
  • Go

A full list of example applications can be viewed with the odo registry command.

Prerequisites​

Step 0. Creating the initial source code (optional)​

We will create the example source code by using some popular frameworks.

This is optional and you may use an existing project instead or a starter project from odo init.

For Node.JS we will use the Express framework for our example.

  1. Install Express:
$ npm install express --save
  1. Generate an example project:
$ npx express-generator

  warning: the default view engine will not be jade in future releases
  warning: use `--view=jade' or `--help' for additional options


   create : public/
   create : public/javascripts/
   create : public/images/
   create : public/stylesheets/
   create : public/stylesheets/style.css
   create : routes/
   create : routes/index.js
   create : routes/users.js
   create : views/
   create : views/error.jade
   create : views/index.jade
   create : views/layout.jade
   create : app.js
   create : package.json
   create : bin/
   create : bin/www

   install dependencies:
     $ npm install

   run the app:
     $ DEBUG=express:* npm start

Your source code has now been generated and created in the directory.

Step 1. Creating your application (odo init)​

Now we'll initialize your application by creating a devfile.yaml to be deployed.

odo handles this automatically with the odo init command by autodetecting your source code and downloading the appropriate Devfile.

Note: If you skipped Step 0, select a "starter project" when running odo init.

Let's run odo init and select Node.js:

$ odo init
  __
 /  \__     Initializing new component
 \__/  \    Files: Source code detected, a Devfile will be determined based upon source code autodetection
 /  \__/    odo version: v3.0.0-alpha2
 \__/

Interactive mode enabled, please answer the following questions:
Based on the files in the current directory odo detected
Language: javascript
Project type: nodejs
The devfile "nodejs" from the registry "DefaultDevfileRegistry" will be downloaded.
? Is this correct? Yes
 ✓  Downloading devfile "nodejs" from registry "DefaultDevfileRegistry" [501ms]
Current component configuration:
Container "runtime":
  Opened ports:
   - 3000
  Environment variables:
? Select container for which you want to change configuration? NONE - configuration is correct
? Enter component name: my-nodejs-app

Your new component 'my-nodejs-app' is ready in the current directory.
To start editing your component, use 'odo dev' and open this folder in your favorite IDE.
Changes will be directly reflected on the cluster.

A devfile.yaml has now been added to your directory and now you're ready to start development.

Step 2. Developing your application continuously (odo dev)​

Now that we've generated our code as well as our Devfile, let's start on development.

odo uses inner loop development and allows you to code, build, run and test the application in a continuous workflow.

Once you run odo dev, you can freely edit code in your favourite IDE and watch as odo rebuilds and redeploys it.

Let's run odo dev to start development on your Node.JS application:

$ odo dev
  __
 /  \__     Developing using the my-nodejs-app Devfile
 \__/  \    Namespace: default
 /  \__/    odo version: v3.0.0-alpha2
 \__/

↪ Deploying to the cluster in developer mode
 ✓  Waiting for Kubernetes resources [3s]
 ✓  Syncing files into the container [330ms]
 ✓  Building your application in container on cluster [4s]
 ✓  Executing the application [1s]

Your application is now running on the cluster
 - Forwarding from 127.0.0.1:40001 -> 3000

Watching for changes in the current directory /Users/user/express
Press Ctrl+c to exit `odo dev` and delete resources from the cluster

You can now access the application at 127.0.0.1:40001 in your local browser and start your development loop. odo will watch for changes and push the code for real-time updates.

Step 3. Deploying your application to the world (odo deploy)​

Prerequisites:

Before we begin, you must login to a container registry that we will be pushing our application to.

Login to your container registry with either podman or docker:

$ podman login
# or
$ docker login

In order for odo deploy to push your image, your container registry needs to be accessible.

NOTE for MacOS: If you are running Apple Silicon (M1/M2), you must set your Docker build platform to the cluster you are deploying to.

For example, if you are deploying to linux/amd64:

export DOCKER_DEFAULT_PLATFORM=linux/amd64

Overview:

There are three steps to deploy your application:

  1. Containerize your application by creating a Dockerfile
  2. Modify devfile.yaml to add your Kubernetes code
  3. Run odo deploy

1. Containerize the application​

In order to deploy our application, we must containerize it in order to build and push to a registry. Create the following Dockerfile in the same directory:

# Sample copied from https://github.com/nodeshift-starters/devfile-sample/blob/main/Dockerfile

# Install the app dependencies in a full Node docker image
FROM registry.access.redhat.com/ubi8/nodejs-14:latest

# Copy package.json and package-lock.json
COPY package*.json ./

# Install app dependencies
RUN npm install --production

# Copy the dependencies into a Slim Node docker image
FROM registry.access.redhat.com/ubi8/nodejs-14-minimal:latest

# Install app dependencies
COPY --from=0 /opt/app-root/src/node_modules /opt/app-root/src/node_modules
COPY . /opt/app-root/src

ENV NODE_ENV production
ENV PORT 3000

CMD ["npm", "start"]

2. Modify the Devfile​

Let's modify the devfile.yaml and add the respective deployment code.

odo deploy uses Devfile schema 2.2.0. Change the schema to reflect the change:

# Deploy "kind" ID's use schema 2.2.0+
schemaVersion: 2.2.0

Add the variables section:

# Add the following variables code anywhere in devfile.yaml
# This MUST be a container registry you are able to access
variables:
  CONTAINER_IMAGE: quay.io/MYUSERNAME/nodejs-odo-example
  RESOURCE_NAME: my-nodejs-app
  CONTAINER_PORT: "3000"
  DOMAIN_NAME: nodejs.example.com

Add the commands used to deploy:

# This is the main "composite" command that will run all below commands
commands:
- id: deploy
  composite:
    commands:
    - build-image
    - k8s-deployment
    - k8s-service
    - k8s-ingress
    group:
      isDefault: true
      kind: deploy

# Below are the commands and their respective components that they are "linked" to deploy
- id: build-image
  apply:
    component: outerloop-build
- id: k8s-deployment
  apply:
    component: outerloop-deployment
- id: k8s-service
  apply:
    component: outerloop-service
- id: k8s-ingress
  apply:
    component: outerloop-ingress

Add the Docker image location and Kubernetes Deployment, Service, and Ingress resources to components:

components:

# This will build the container image before deployment
- name: outerloop-build
  image:
    dockerfile:
      buildContext: ${PROJECT_SOURCE}
      rootRequired: false
      uri: ./Dockerfile
    imageName: "{{CONTAINER_IMAGE}}"

# This will create a Deployment in order to run your container image across
# the cluster.
- name: outerloop-deployment
  kubernetes:
    inlined: |
      kind: Deployment
      apiVersion: apps/v1
      metadata:
        name: {{RESOURCE_NAME}}
      spec:
        replicas: 1
        selector:
          matchLabels:
            app: {{RESOURCE_NAME}}
        template:
          metadata:
            labels:
              app: {{RESOURCE_NAME}}
          spec:
            containers:
              - name: {{RESOURCE_NAME}}
                image: {{CONTAINER_IMAGE}}
                ports:
                  - name: http
                    containerPort: {{CONTAINER_PORT}}
                    protocol: TCP
                resources:
                  limits:
                    memory: "1024Mi"
                    cpu: "500m"

# This will create a Service so your Deployment is accessible.
# Depending on your cluster, you may modify this code so it's a
# NodePort, ClusterIP or a LoadBalancer service.
- name: outerloop-service
  kubernetes:
    inlined: |
      apiVersion: v1
      kind: Service
      metadata:
        name: {{RESOURCE_NAME}}
      spec:
        ports:
        - name: "{{CONTAINER_PORT}}"
          port: {{CONTAINER_PORT}}
          protocol: TCP
          targetPort: {{CONTAINER_PORT}}
        selector:
          app: {{RESOURCE_NAME}}
        type: ClusterIP

# Let's create an Ingress so we can access the application via a domain name
- name: outerloop-ingress
  kubernetes:
    inlined: |
      apiVersion: networking.k8s.io/v1
      kind: Ingress
      metadata:
        name: {{RESOURCE_NAME}}
      spec:
        rules:
          - host: "{{DOMAIN_NAME}}"
            http:
              paths:
                - path: "/"
                  pathType: Prefix
                  backend:
                    service:
                      name: {{RESOURCE_NAME}} 
                      port:
                        number: {{CONTAINER_PORT}}

3. Run the odo deploy command​

Now we're ready to run odo deploy:

$ odo deploy
  __
 /  \__     Deploying the application using my-nodejs-app Devfile
 \__/  \    Namespace: default
 /  \__/    odo version: v3.0.0-alpha2
 \__/

↪ Building & Pushing Container: MYUSERNAME/nodejs-odo-example
 •  Building image locally  ...
 ✓  Building image locally [880ms]
 •  Pushing image to container registry  ...
 ✓  Pushing image to container registry [5s]

↪ Deploying Kubernetes Component: nodejs-example
 ✓  Searching resource in cluster
 ✓  Creating kind Deployment [48ms]

↪ Deploying Kubernetes Component: nodejs-example
 ✓  Searching resource in cluster
 ✓  Creating kind Service [51ms]

↪ Deploying Kubernetes Component: nodejs-example
 ✓  Searching resource in cluster
 ✓  Creating kind Ingress [49ms]

Your Devfile has been successfully deployed

Your application has now been deployed to the Kubernetes cluster with Deployment, Service, and Ingress resources.

Test your application by visiting the DOMAIN_NAME variable that you had set in the devfile.yaml.

(OPTIONAL) 4. Delete the resources​

After testing your application, you may optionally undeploy using the odo delete component command:

odo delete component
Searching resources to delete, please wait...
This will delete "my-app" from the namespace "default".
 •  The component contains the following resources that will get deleted:
        - Deployment: my-app
        - Service: my-app
        - Ingress: my-app
? Are you sure you want to delete "my-app" and all its resources? Yes
The component "my-app" is successfully deleted from namespace "default"
 •  There are still resources left in the cluster that might be belonging to the deleted component.
        - Endpoints: svc
        - Service: svc
If you want to delete those, execute `odo delete component --name my-app --namespace default`