Lab: Deploy Managed and Networked Applications on Kubernetes

Deploy a database server and a web application that connects to that database and expose the web application to external access.

Outcomes

  • Deploy a MySQL database from a container image.

  • Deploy a web application from a container image.

  • Configure environment variables for a deployment.

  • Expose the web application for external access.

As the student user on the workstation machine, use the lab command to prepare your system for this exercise.

This command ensures that the cluster is accessible and that all exercise resources are available. It also creates the database-applications project.

[student@workstation ~]$ lab start deploy-review

Instructions

The API URL of your OpenShift cluster is https://api.ocp4.example.com:6443, and the oc command is already installed on your workstation machine.

Log in to the OpenShift cluster as the developer user with the developer password.

Use the database-applications project for your work.

  1. Log in to the OpenShift cluster and change to the database-applications project.

    1. Log in to the OpenShift cluster.

      [student@workstation ~]$ oc login -u developer -p developer \
  https://api.ocp4.example.com:6443
Login successful
...output omitted...

    2. Change to the database-applications project.

      [student@workstation ~]$ oc project database-applications
Now using project "database-applications" on server "https://api.ocp4.example.com:6443".
...output omitted...

  2. Create a MySQL database deployment named mysql-app by using the registry.ocp4.example.com:8443/redhattraining/mysql-app:v1 image, and identify the root cause of the failure.

    1. Create the MySQL database deployment. Ignore the warning message.

      [student@workstation ~]$ oc create deployment mysql-app \
  --image registry.ocp4.example.com:8443/redhattraining/mysql-app:v1
deployment.apps/mysql-app created

    2. Verify the deployment status. The pod name might differ in your output.

      [student@workstation ~]$ oc get pods
NAME              	          READY  STATUS  ...
mysql-app-75dfd58f99-5xfqc   0/1    Error   ...
[student@workstation ~]$ oc status
...output omitted...
Errors:
  pod/mysql-app-75dfd58f99-5xfqc is crash-looping

1 error, 1 info identified, use 'oc status --suggest' to see details.

    3. Identify the root cause of the deployment failure.

      [student@workstation ~]$ oc logs mysql-app-75dfd58f99-5xfqc
...output omitted...
You must either specify the following environment variables:
  MYSQL_USER
  MYSQL_PASSWORD
  MYSQL_DATABASE
Or the following environment variable:
  MYSQL_ROOT_PASSWORD (regex: '^[a-zA-Z0-9_~!@#$%^&*()-=<>,.?;:|]+$')
...output omitted...

  3. Configure the environment variables for the mysql-app deployment by using the following information:

    FieldValue
    MYSQL_USER redhat
    MYSQL_PASSWORD redhat123
    MYSQL_DATABASE world_x

    Then, execute the following command in the mysql-app deployment pod to load the world_x database:

    /bin/bash -c "mysql -uredhat -predhat123 </tmp/world_x.sql"

    1. Update the environment variables for the mysql-app deployment.

      [student@workstation ~]$ oc set env deployment/mysql-app \
  MYSQL_USER=redhat MYSQL_PASSWORD=redhat123 MYSQL_DATABASE=world_x
deployment.apps/mysql-app updated

    2. Verify that the mysql-app application pod is in the RUNNING state. The pod name might differ in your output.

      [student@workstation ~]$ oc get pods
NAME		                      READY   STATUS   ...
mysql-app-57c44f646-5qt2k   1/1     Running  ...

    3. Load the world_x database.

      [student@workstation ~]$ oc exec -it mysql-app-57c44f646-5qt2k \
  -- /bin/bash -c "mysql -uredhat -predhat123 </tmp/world_x.sql"
...output omitted..
[student@workstation ~]$

    4. Confirm that you can access the MySQL database.

      [student@workstation ~]$ oc rsh mysql-app-57c44f646-5qt2k
      sh-4.4$ mysql -uredhat -predhat123 world_x
...output omitted...
mysql>

    5. Exit the MySQL database, and then exit the container.

      mysql> exit
Bye
sh-4.4$ exit

  4. Create a service for the mysql-app deployment by using the following information:

    FieldValue
    Name mysql-service
    Port 3306
    Target port 3306

    1. Expose the mysql-app deployment.

      [student@workstation ~]$ oc expose deployment mysql-app --name mysql-service \
  --port 3306 --target-port 3306
service/mysql-service created

    2. Verify the service configuration. The endpoint IP address might differ in your output.

      [student@workstation ~]$ oc get services
NAME            TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
mysql-service   ClusterIP   172.30.146.213   <none>        3306/TCP   10s
[student@workstation ~]$ oc get endpoints
NAME            ENDPOINTS         AGE
mysql-service   10.8.0.102:3306   19s

  5. Create a web application deployment named php-app by using the registry.ocp4.example.com:8443/redhattraining/php-webapp:v1 image.

    1. Create the web application deployment. Ignore the warning message.

      [student@workstation ~]$ oc create deployment php-app \
  --image registry.ocp4.example.com:8443/redhattraining/php-webapp:v1
deployment.apps/php-app created

    2. Verify the deployment status. Verify that the php-app application pod is in the RUNNING state.

      [student@workstation ~]$ oc get pods
NAME              READY  STATUS   ...
php-app-725...    1/1    Running  ...
mysql-app-57c...  1/1    Running  ...
      [student@workstation ~]$ oc status
...output omitted...
deployment/php-app deploys registry.ocp4.example.com:8443/redhattraining/php-webapp:v1
  deployment #1 running for about a minute - 1 pod
...output omitted...

  6. Create a service for the php-app deployment by using the following information:

    FieldValue
    Name php-svc
    Port 8080
    Target port 8080

    Then, create a route named phpapp to expose the web application to external access.

    1. Expose the php-app deployment.

      [student@workstation ~]$ oc expose deployment php-app --name php-svc \
  --port 8080 --target-port 8080
service/php-svc exposed

    2. Verify the service configuration. The endpoint IP address might differ in your output.

      [student@workstation ~]$ oc get services
NAME            TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
mysql-service   ClusterIP   172.30.146.213   <none>        3306/TCP   7m47s
php-svc         ClusterIP   172.30.228.80    <none>        8080/TCP   4m34s
[student@workstation ~]$ oc get endpoints
NAME            ENDPOINTS         AGE
mysql-service   10.8.0.102:3306   7m50s
php-svc         10.8.0.107:8080   4m37s

    3. Expose the php-svc service.

      [student@workstation ~]$ oc expose service/php-svc --name phpapp
route.route.openshift.io/phpapp exposed
      [student@workstation ~]$ oc get routes
NAME    HOST/PORT                             ...
phpapp  phpapp-database-applications.apps.ocp4.example.com  ...

  7. Test the connectivity between the web application and the MySQL database. In a web browser, navigate to the phpapp-database-applications.apps.ocp4.example.com route, and verify that the application retrieves data from the MySQL database.

    1. Navigate to the phpapp-database-applications.apps.ocp4.example.com route in the web browser.

Evaluation

As the student user on the workstation machine, use the lab command to grade your work. Correct any reported failures and rerun the command until successful.

[student@workstation ~]$ lab grade deploy-review

Finish

As the student user on the workstation machine, use the lab command to complete this exercise. This step is important to ensure that resources from previous exercises do not impact upcoming exercises.

[student@workstation ~]$ lab finish deploy-review