Creating an application with a database - OpenShift Do developer CLI (odo) | CLI tools

Creating a project
Deploying the front-end component
Deploying a database in interactive mode
Deploying a database manually
Connecting the database to the front-end application
Deleting an application

This example describes how to deploy and connect a database to a front-end application.

Prerequisites

odo is installed.
oc client is installed.
You have a running OpenShift Container Platform cluster. Developers can use CodeReady Containers (CRC) to deploy a local OpenShift Container Platform cluster quickly.
Service Catalog is enabled.

Creating a project

Create a project to keep your source code, tests, and libraries organized in a separate single unit.

Procedure

Create a project:

$ odo project create myproject
 ✓  Project 'myproject' is ready for use
 ✓  New project created and now using project : myproject

Deploying the front-end component

To create and deploy a front-end component, download the Node.js application and push the source code to your cluster with odo.

Procedure

Download the example front-end application:

$ git clone https://github.com/openshift/nodejs-ex

Change the current directory to the front-end directory:
```
$ cd <directory-name>
```
List the contents of the directory to see that the front end is a Node.js application.
```
$ ls
assets  bin  index.html  kwww-frontend.iml  package.json  package-lock.json  playfield.png  README.md  server.js
```
The front-end component is written in an interpreted language (Node.js); it does not need to be built.

Create a component configuration of Node.js component-type named frontend:

$ odo create nodejs frontend
 ✓  Validating component [5ms]
Please use `odo push` command to create the component with source deployed

Create a URL to access the frontend interface.

$ odo url create myurl
 ✓  URL myurl created for component: nodejs-nodejs-ex-pmdp

Push the component to the OpenShift Container Platform cluster.

$ odo push
Validation
 ✓  Checking component [7ms]

 Configuration changes
 ✓  Initializing component
 ✓  Creating component [134ms]

 Applying URL changes
 ✓  URL myurl: http://myurl-app-myproject.192.168.42.79.nip.io created

 Pushing to component nodejs-nodejs-ex-mhbb of type local
 ✓  Checking files for pushing [657850ns]
 ✓  Waiting for component to start [6s]
 ✓  Syncing files to the component [408ms]
 ✓  Building component [7s]
 ✓  Changes successfully pushed to component

Deploying a database in interactive mode

odo provides a command-line interactive mode which simplifies deployment.

Procedure

Run the interactive mode and answer the prompts:

$ odo service create
? Which kind of service do you wish to create database
? Which database service class should we use mongodb-persistent
? Enter a value for string property DATABASE_SERVICE_NAME (Database Service Name): mongodb
? Enter a value for string property MEMORY_LIMIT (Memory Limit): 512Mi
? Enter a value for string property MONGODB_DATABASE (MongoDB Database Name): sampledb
? Enter a value for string property MONGODB_VERSION (Version of MongoDB Image): 3.2
? Enter a value for string property VOLUME_CAPACITY (Volume Capacity): 1Gi
? Provide values for non-required properties No
? How should we name your service  mongodb-persistent
? Output the non-interactive version of the selected options No
? Wait for the service to be ready No
 ✓  Creating service [32ms]
 ✓  Service 'mongodb-persistent' was created
Progress of the provisioning will not be reported and might take a long time.
You can see the current status by executing 'odo service list'

Your password or username will be passed to the front-end application as environment variables.

Deploying a database manually

List the available services:

$ odo catalog list services
NAME                         PLANS
django-psql-persistent       default
jenkins-ephemeral            default
jenkins-pipeline-example     default
mariadb-persistent           default
mongodb-persistent           default
mysql-persistent             default
nodejs-mongo-persistent      default
postgresql-persistent        default
rails-pgsql-persistent       default

Choose the mongodb-persistent type of service and see the required parameters:

$ odo catalog describe service mongodb-persistent
  ***********************        | *****************************************************
  Name                           | default
  -----------------              | -----------------
  Display Name                   |
  -----------------              | -----------------
  Short Description              | Default plan
  -----------------              | -----------------
  Required Params without a      |
  default value                  |
  -----------------              | -----------------
  Required Params with a default | DATABASE_SERVICE_NAME
  value                          | (default: 'mongodb'),
                                 | MEMORY_LIMIT (default:
                                 | '512Mi'), MONGODB_VERSION
                                 | (default: '3.2'),
                                 | MONGODB_DATABASE (default:
                                 | 'sampledb'), VOLUME_CAPACITY
                                 | (default: '1Gi')
  -----------------              | -----------------
  Optional Params                | MONGODB_ADMIN_PASSWORD,
                                 | NAMESPACE, MONGODB_PASSWORD,
                                 | MONGODB_USER

Pass the required parameters as flags and wait for the deployment of the database:

$ odo service create mongodb-persistent --plan default --wait -p DATABASE_SERVICE_NAME=mongodb -p MEMORY_LIMIT=512Mi -p MONGODB_DATABASE=sampledb -p VOLUME_CAPACITY=1Gi

Connecting the database to the front-end application

Link the database to the front-end service:

$ odo link mongodb-persistent
 ✓  Service mongodb-persistent has been successfully linked from the component nodejs-nodejs-ex-mhbb

Following environment variables were added to nodejs-nodejs-ex-mhbb component:
- database_name
- password
- uri
- username
- admin_password

See the environment variables of the application and the database in the Pod:

$ oc get pods
NAME                                READY     STATUS    RESTARTS   AGE
mongodb-1-gsznc                     1/1       Running   0          28m
nodejs-nodejs-ex-mhbb-app-4-vkn9l   1/1       Running   0          1m

$ oc rsh nodejs-nodejs-ex-mhbb-app-4-vkn9l
sh-4.2$ env
uri=mongodb://172.30.126.3:27017
password=dHIOpYneSkX3rTLn
database_name=sampledb
username=user43U
admin_password=NCn41tqmx7RIqmfv
sh-4.2$

Open the URL in the browser and notice the database configuration in the bottom right:

$ odo url list

Request information
Page view count: 24

DB Connection Info:
Type:	MongoDB
URL:	mongodb://172.30.126.3:27017/sampledb

Deleting an application

Deleting an application will delete all components associated with the application.

Procedure

List the applications in the current project:

$ odo app list
    The project '<project_name>' has the following applications:
    NAME
    app

List the components associated with the applications. These components will be deleted with the application:

$ odo component list
    APP     NAME                      TYPE       SOURCE        STATE
    app     nodejs-nodejs-ex-elyf     nodejs     file://./     Pushed

Delete the application:

$ odo app delete <application_name>
    ? Are you sure you want to delete the application: <application_name> from project: <project_name>

Confirm the deletion with Y. You can suppress the confirmation prompt using the -f flag.