Creating an application with a database

    Prerequisites

    • is installed.

    • oc client is installed.

    • You have a running cluster. Developers can use CodeReady Containers (CRC) to deploy a local cluster quickly.

    • The Service Catalog is installed and enabled on your cluster.

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

    Procedure

    1. Log in to an OKD cluster:

    2. Create a project:

      1. $ odo project create myproject

      Example output

      1.  ✓  Project 'myproject' is ready for use
      2.  ✓  New project created and now using project : myproject

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

    Procedure

    1. Download the example front-end application:

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

    3. List the contents of the directory to see that the front end is a Node.js application.

      1. $ ls

      Example output

      1. README.md       openshift       server.js       views
      2. helm            package.json    tests

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

      1. $ odo create --s2i nodejs frontend

      Example output

      1.  ✓  Validating component [5ms]
      2. Please use `odo push` command to create the component with source deployed

    5. Create a URL to access the frontend interface.

      Example output

      1.  ✓  URL myurl created for component: nodejs-nodejs-ex-pmdp

    6. Push the component to the OKD cluster.

      1. $ odo push

      Example output

      1. Validation
      2.  ✓  Checking component [7ms]
      4.  Configuration changes
      5.  ✓  Initializing component
      6.  ✓  Creating component [134ms]
      7.  Applying URL changes
      8.  ✓  URL myurl: http://myurl-app-myproject.192.168.42.79.nip.io created
      10.  Pushing to component nodejs-nodejs-ex-mhbb of type local
      11.  ✓  Checking files for pushing [657850ns]
      13.  ✓  Syncing files to the component [408ms]
      14.  ✓  Building component [7s]
      15.  ✓  Changes successfully pushed to component

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

    Procedure

    • Run the interactive mode and answer the prompts:

      1. $ odo service create

      Example output

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

      Example output

      1. NAME                         PLANS
      2. django-psql-persistent       default
      3. jenkins-ephemeral            default
      4. jenkins-pipeline-example     default
      5. mariadb-persistent           default
      6. mongodb-persistent           default
      7. mysql-persistent             default
      8. nodejs-mongo-persistent      default
      9. rails-pgsql-persistent       default

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

      1. $ odo catalog describe service mongodb-persistent

      Example output

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

      1. $ 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

    1. Link the database to the front-end service:

      1. $ odo link mongodb-persistent

      Example output

      1.  ✓  Service mongodb-persistent has been successfully linked from the component nodejs-nodejs-ex-mhbb
      3. Following environment variables were added to nodejs-nodejs-ex-mhbb component:
      4. - database_name
      5. - password
      6. - uri
      7. - username
      8. - admin_password

    2. See the environment variables of the application and the database in the pod:

      1. Get the pod name:

        1. $ oc get pods

        Example output

        1. NAME                                READY     STATUS    RESTARTS   AGE
        2. mongodb-1-gsznc                     1/1       Running   0          28m
        3. nodejs-nodejs-ex-mhbb-app-4-vkn9l   1/1       Running   0          1m

      2. Connect to the pod:

        1. $ oc rsh nodejs-nodejs-ex-mhbb-app-4-vkn9l

      3. Check the environment variables:

        1. sh-4.2$ env

        Example output

        1. uri=mongodb://172.30.126.3:27017
        2. password=dHIOpYneSkX3rTLn
        3. database_name=sampledb
        4. username=user43U
        5. admin_password=NCn41tqmx7RIqmfv

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

      Example output

      1. Request information
      2. Page view count: 24
      4. DB Connection Info: