Lab: Manage Storage for Application Configuration and Data

Deploy a web application and its database that share database credentials from a secret. The database should use the default storage for the cluster. Also deploy a file-sharing application that runs with multiple replicas and shares its storage volume with a file uploader application. The file sharing and file uploader applications take configuration files from a config map and should use NFS file storage for shareability. The database should use local storage for increased performance.

Outcomes

  • Deploy a database server.

  • Deploy a web application.

  • Create a secret that contains the database server credentials.

  • Create a configuration map that contains an SQL file.

  • Add and remove a volume on the database server and the web application.

  • Expose the database server and the web application.

  • Scale up the web application.

  • Mount the configuration map as a volume.

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 storage-review project, and it creates files that this lab uses, in the /home/student/DO180/labs/storage-review directory.

[student@workstation ~]$ lab start storage-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 storage-review project for your work.

  1. Log in to the OpenShift cluster and change to the storage-review project.

    1. Log in to the OpenShift cluster.

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

    2. Change to the storage-review project.

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

  2. Create a secret named world-cred that contains the following data:

    FieldValue
    user redhat
    password redhat123
    database world_x

    1. Create a secret that contains the database credentials.

      [student@workstation]$ oc create secret generic world-cred \
  --from-literal user=redhat \
  --from-literal password=redhat123 \
  --from-literal database=world_x
secret/world-cred created

    2. Confirm the creation of the secret.

      [student@workstation ~]$ oc get secrets world-cred
NAME         TYPE     DATA   AGE
world-cred   Opaque   3      2m34s

  3. Create a configuration map named dbfiles by using the ~/DO180/labs/storage-review/insertdata.sql file.

    1. Create a configuration map named dbfiles by using the insertdata.sql file in the ~/DO180/labs/storage-review directory.

      [student@workstation ~]$ oc create configmap dbfiles \
  --from-file ~/DO180/labs/storage-review/insertdata.sql
configmap/dbfiles created

    2. Verify the creation of the configuration map.

      [student@workstation]$ oc get configmaps
NAME	 DATA  AGE
dbfiles  1     11s
...output omitted...

  4. Create a database server deployment named dbserver by using the registry.ocp4.example.com:8443/redhattraining/mysql-app:v1 container image. Then, set the missing environment variables by using the world-cred secret.

    1. Create the database server deployment.

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

    2. Set the missing environment variables.

      [student@workstation ~]$ oc set env deployment/dbserver --from secret/world-cred \
  --prefix MYSQL_
deployment.apps/dbserver updated

    3. Verify that the dbserver pod is in the RUNNING state. The pod name might differ in your output.

      [student@workstation ~]$ oc get pods
NAME                        READY   STATUS  ...
dbserver-6d5bf5d86c-ptrb2   1/1     Running ...

  5. Add a volume to the dbserver deployment by using the following information:

    FieldValue
    name dbserver-lvm
    type persistentVolumeClaim
    claim mode rwo
    claim size 1Gi
    mount path /var/lib/mysql
    claim class lvms-vg1
    claim name dbserver-lvm-pvc

    1. Add a volume to the dbserver deployment.

      [student@workstation ~]$ oc set volume deployment/dbserver \
  --add --name dbserver-lvm --type persistentVolumeClaim \
  --claim-mode rwo --claim-size 1Gi --mount-path /var/lib/mysql \
  --claim-class lvms-vg1 --claim-name dbserver-lvm-pvc
deployment.apps/dbserver volume updated

    2. Verify the deployment status.

      [student@workstation ~]$ oc get pods
NAME              	    READY   STATUS   ...
dbserver-5bc6bd5d7b-7z7lv   1/1     Running  ...

    3. Verify the volume status.

      [student@workstation ~]$ oc get pvc
NAME              STATUS   VOLUME             CAPACITY ...output omitted...
dbserver-lvm-pvc  Bound    pvc-2cb85025-...   1Gi      ...output omitted...

  6. Create a service for the dbserver deployment by using the following information:

    FieldValue
    Name mysql-service
    Port 3306
    Target port 3306

    1. Expose the dbserver deployment.

      [student@workstation ~]$ oc expose deployment dbserver --name mysql-service \
  --port 3306 --target-port 3306
service/mysql-service 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)   ...
mysql-service   ClusterIP   172.30.240.100  <none>        3306/TCP  ...
      [student@workstation ~]$ oc get endpoints
NAME            ENDPOINTS      ...
mysql-service   10.8.1.36:3306 ...

  7. Create a web application deployment named file-sharing by using the registry.ocp4.example.com:8443/redhattraining/php-webapp-mysql:v1 container image. Scale the deployment to two replicas. Then, expose the deployment by using the following information:

    FieldValue
    Name file-sharing
    Port 8080
    Target port 8080

    Create a route named file-sharing to expose the file-sharing web application to external access. Access the file-sharing route in a web browser to test the connection between the web application and the database server.

    1. Create a web application deployment.

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

    2. Verify the deployment status. Verify that the file-sharing application pod is in the RUNNING state. The pod names might differ on your system.

      [student@workstation ~]$ oc get pods
NAME                            READY   STATUS   ...
dbserver-5bc6bd5d7b-7z7lv       1/1     Running  ...
file-sharing-789c5948c8-gdrlz   1/1     Running  ...

    3. Scale the deployment to two replicas.

      [student@workstation ~]$ oc scale deployment file-sharing --replicas 2
deployment.apps/file-sharing scaled

    4. Verify the replica status and retrieve the pod name. The pod names might differ on your system.

      [student@workstation ~]$ oc get pods
NAME                            READY   STATUS    ...
dbserver-5bc6bd5d7b-7z7lv       1/1     Running   ...
file-sharing-789c5948c8-62j9s   1/1     Running   ...
file-sharing-789c5948c8-gdrlz   1/1     Running   ...

    5. Expose the file-sharing deployment.

      [student@workstation ~]$ oc expose deployment file-sharing --name file-sharing \
  --port 8080 --target-port 8080
service/file-sharing exposed

    6. 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)   ...
file-sharing    ClusterIP   172.30.139.210  <none>        8080/TCP  ...
mysql-service   ClusterIP   172.30.240.100  <none>        3306/TCP  ...
      [student@workstation ~]$ oc get endpoints
NAME           ENDPOINTS
file-sharing   10.8.1.37:8080,10.8.1.38:8080   ...
mysql-service  10.8.1.36:3306                  ...

    7. Expose the file-sharing service.

      [student@workstation ~]$ oc expose service/file-sharing
route.route.openshift.io/file-sharing exposed
      [student@workstation ~]$ oc get routes
NAME           HOST/PORT                                           ...   SERVICES     ...
file-sharing   file-sharing-storage-review.apps.ocp4.example.com   ...   file-sharing ...

    8. Test the connectivity between the web application and the database server. In a web browser, navigate to http://file-sharing-storage-review.apps.ocp4.example.com, and verify that a Connected successfully message is displayed.

  8. Mount the dbfiles configuration map to the file-sharing deployment as a volume named config-map-pvc. Set the mount path to the /home/database-files directory. Then, verify the content of the insertdata.sql file.

    1. Mount the dbfiles configuration map to the file-sharing deployment.

      [student@workstation ~]$ oc set volume deployment/file-sharing \
  --add --name config-map-pvc --type configmap \
  --configmap-name dbfiles \
  --mount-path /home/database-files
deployment.apps/file-sharing volume updated

    2. Verify the deployment status.

      [student@workstation ~]$ oc get pods
NAME              	        READY   STATUS   ...
dbserver-5bc6bd5d7b-7z7lv       1/1     Running  ...
file-sharing-7f77855b7f-949lg   1/1     Running  ...
file-sharing-7f77855b7f-9zvwq   1/1     Running  ...

    3. Verify the content of the /home/database-files/insertdata.sql file.

      [student@workstation ~]$ oc exec -it pod/file-sharing-7f77855b7f-949lg -- \
  head /home/database-files/insertdata.sql
-- MySQL dump 10.13  Distrib 8.0.19, for osx10.14 (x86_64)
--
-- Host: 127.0.0.1    Database: world_x
-- ------------------------------------------------------
-- Server version	8.0.19-debug
...output omitted...

  9. Add a shared volume to the file-sharing deployment. Use the following information to create the volume:

    FieldValue
    Name shared-volume
    Type persistentVolumeClaim
    Claim mode rwo
    Claim size 1Gi
    Mount path /home/sharedfiles
    Claim class nfs-storage
    Claim name shared-pvc

    Next, connect to a file-sharing deployment pod and then use the cp command to copy the /home/database-files/insertdata.sql file to the /home/sharedfiles directory. Then, remove the config-map-pvc volume from the file-sharing deployment.

    1. Add the shared-volume volume to the file-sharing deployment.

      [student@workstation ~]$ oc set volume deployment/file-sharing \
  --add --name shared-volume --type persistentVolumeClaim \
  --claim-mode rwo --claim-size 1Gi --mount-path /home/sharedfiles \
  --claim-class nfs-storage --claim-name shared-pvc
deployment.apps/file-sharing volume updated

    2. Verify the deployment status. Your pod names might differ on your system.

      [student@workstation ~]$ oc get pods
NAME              	              READY   STATUS  ...
dbserver-5bc6bd5d7b-7z7lv       1/1     Running ...
file-sharing-65884f75bb-92fxf   1/1     Running ...
file-sharing-65884f75bb-gsghk   1/1     Running ...

    3. Verify the volume status.

      [student@workstation ~]$ oc get pvc
NAME              STATUS   VOLUME      CAPACITY   ACCESS MODES   STORAGECLASS
dbserver-lvm-pvc  Bound    pvc-2cb...  1Gi        RWO            lvms-vg1    ...
shared-pvc        Bound    pvc-cf2...  1Gi        RWO            nfs-storage ...

    4. Copy the /home/database-files/insertdata.sql file to the /home/sharedfiles path.

      [student@workstation ~]$ oc exec -it pod/file-sharing-65884f75bb-92fxf -- \
  cp /home/database-files/insertdata.sql /home/sharedfiles/
      [student@workstation ~]$ oc exec -it pod/file-sharing-65884f75bb-92fxf -- \
  ls /home/sharedfiles/
insertdata.sql

    5. Remove the config-map-pvc volume from the file-sharing deployment.

      [student@workstation ~]$ oc set volume deployment/file-sharing \
  --remove --name=config-map-pvc
deployment.apps/file-sharing volume updated

  10. Add the shared-volume PVC to the dbserver deployment. Then, connect to a dbserver deployment pod and verify the content of the /home/sharedfiles/insertdata.sql file.

    1. Add the shared-volume volume to the dbserver deployment.

      [student@workstation ~]$ oc set volume deployment/dbserver \
  --add --name shared-volume \
  --claim-name shared-pvc \
  --mount-path /home/sharedfiles
deployment.apps/dbserver volume updated

    2. Verify the deployment status. The pod names might differ on your system.

      [student@workstation ~]$ oc get pods
NAME              	              READY   STATUS   ...
dbserver-6676fbf5fc-n9hpk       1/1     Running  ...
file-sharing-5fdb44cf57-2hhwj   1/1     Running  ...
file-sharing-5fdb44cf57-z4n7g   1/1     Running  ...

    3. Verify the content of the /home/sharedfiles/insertdata.sql file.

      [student@workstation ~]$ oc exec -it pod/dbserver-6676fbf5fc-n9hpk -- \
  head /home/sharedfiles/insertdata.sql
-- MySQL dump 10.13  Distrib 8.0.19, for osx10.14 (x86_64)
--
-- Host: 127.0.0.1    Database: world_x
-- ------------------------------------------------------
-- Server version	8.0.19-debug
...output omitted...

  11. Connect to the database server and execute the /home/sharedfiles/insertdata.sql file to add data to the world_x database. You can execute the file by using the following command:

    mysql -u$MYSQL_USER -p$MYSQL_PASSWORD world_x </home/sharedfiles/insertdata.sql

    Then, confirm connectivity between the web application and database server by accessing the file-sharing route in a web browser.

    1. Connect to the database server and execute the /home/sharedfiles/insertdata.sql file. Then, exit the database server.

      [student@workstation ~]$ oc rsh dbserver-6676fbf5fc-n9hpk
      sh-4.4$ mysql -u$MYSQL_USER -p$MYSQL_PASSWORD world_x </home/sharedfiles/insertdata.sql
mysql: [Warning] Using a password on the command line interface can be insecure.
sh-4.4$ exit
exit

    2. Test the connectivity between the web application and the database server. In a web browser, navigate to http://file-sharing-storage-review.apps.ocp4.example.com, and verify that the application retrieves data from the world_x database.

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 storage-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 storage-review