DO288 - ch04s04

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Guided Exercise: Managing Application Builds

Configure and manage Red Hat OpenShift builds.

Outcomes

Use the CLI to manage builds on OpenShift.

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

[student@workstation ~]$ lab start builds-applications

Instructions

Inspect the source code for the sample application.
1. Navigate to the ~/DO288/DO288-apps/apps/builds-applications/vertx-site directory.
```
[student@workstation ~]$ cd ~/DO288/DO288-apps/apps/builds-applications/vertx-site
...no output expected...
```
2. Open the pom.xml file. Notice the maven-shade-plugin configuration:
```
...output omitted...
<plugin>
  <artifactId>maven-shade-plugin</artifactId>
  <version>${maven-shade-plugin.version}</version>
  <executions>
...output omitted...
  <outputFile>${project.build.directory}/${project.artifactId}-${project.version}-fat.jar</outputFile>
...output omitted...
```
  The build process creates the vertx-site-1.0.0-SNAPSHOT-fat.jar shaded JAR file, which you can execute by using the java -jar command.
3. Explore the src/main/java/com/redhat/vertx_site/MainVerticle.java file.
  The application listens on port 8080 and returns HTML text.

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

Ensure that you use the builds-applications project.

[student@workstation vertx-site]$ oc project builds-applications
Already on project "builds-applications" on server "https://api.ocp4.example.com:6443".

Create an application build.

Build the vertx-site application from source code in Git.
Use the following parameters for the build:
- Application name: vertx-site
- Build environment variable: MAVEN_MIRROR_URL=http://nexus-infra.apps.ocp4.example.com/java
- Environment variable: JAVA_APP_JAR=vertx-site-1.0.0-SNAPSHOT-fat.jar
- Image stream: redhat-openjdk18-openshift:1.8
- Build directory: apps/builds-applications/vertx-site
- Source code: https://git.ocp4.example.com/developer/DO288-apps
You can execute the oc-new-app.sh script in the current vertx-site directory, or execute the command manually:
```
[student@workstation vertx-site]$ oc new-app --name vertx-site \
--build-env \
MAVEN_MIRROR_URL=http://nexus-infra.apps.ocp4.example.com/java \
--env JAVA_APP_JAR=vertx-site-1.0.0-SNAPSHOT-fat.jar \
-i redhat-openjdk18-openshift:1.8 \
--context-dir apps/builds-applications/vertx-site \
https://git.ocp4.example.com/developer/DO288-apps
--> Found image 11c20bc (23 months old) in image stream ...output omitted...
```

See the build logs.

[student@workstation vertx-site]$ oc logs -f buildconfig/vertx-site
Cloning "https://git.ocp4.example.com/developer/DO288-apps" ...
...output omitted...
[INFO] Downloading from mirror.default: http://nexus-infra.apps.ocp4.example.com/java/io/vertx/vertx-stack-depchain/4.4.4/vertx-stack-depchain-4.4.4.pom
[ERROR] [ERROR] Some problems were encountered while processing the POMs:
[ERROR] Non-resolvable import POM: Could not find artifact io.vertx:vertx-stack-depchain:pom:4.4.4 in mirror.default (http://nexus-infra.apps.ocp4.example.com/java) @ line 28, column 19
...output omitted...

The build failed because it could not download application dependencies.

See the build status.

[student@workstation vertx-site]$ oc get build
NAME           TYPE     FROM          STATUS ...
vertx-site-1   Source   Git@8e8b86d   Failed (GenericBuildFailed) ...

Verify the correct classroom Maven repository URL.

[student@workstation vertx-site]$ cat ~/.m2/settings.xml
...output omitted...
<url>http://nexus-infra.apps.ocp4.example.com/repository/java</url>
...output omitted...

The build environment variable is missing the /repository/ part of the Maven repository URL.

Correct the application build by using the correct MAVEN_MIRROR_URL build variable.

Delete OpenShift objects in the current project.

[student@workstation vertx-site]$ oc delete all --all
service "vertx-site" deleted
deployment.apps "vertx-site" deleted
...output omitted...

Re-execute the previous oc new-app command with the correct Maven repository URL.

[student@workstation vertx-site]$ oc new-app --name vertx-site \
--build-env \
MAVEN_MIRROR_URL=http://nexus-infra.apps.ocp4.example.com/repository/java \
--env JAVA_APP_JAR=vertx-site-1.0.0-SNAPSHOT-fat.jar \
-i redhat-openjdk18-openshift:1.8 \
--context-dir apps/builds-applications/vertx-site \
https://git.ocp4.example.com/developer/DO288-apps
--> Found image 11c20bc (23 months old) in image stream ...output omitted...

Wait for the build object to finish.

[student@workstation vertx-site]$ oc wait --for=condition=complete \
--timeout=600s build/vertx-site-1
build.build.openshift.io/vertx-site-1 condition met

Verify the application pods.

[student@workstation vertx-site]$ oc get po
NAME                         READY   STATUS      RESTARTS      AGE
vertx-site-1-build            0/1     Completed   0          65s
vertx-site-7b9db94ffc-9bdkt   1/1     Running     0          29s

Expose the application by creating a route.

[student@workstation vertx-site]$ oc expose svc vertx-site
route.route.openshift.io/vertx-site exposed

Verify that the application is accessible:

[student@workstation vertx-site] curl \
vertx-site-builds-applications.apps.ocp4.example.com
<html><body><h1>Welcome to your Vert.x v1.0 application!</h1></body></html>

Modify and rebuild the application.

Modify the handleRoot method in the src/main/java/com/redhat/vertx_site/MainVerticle.java file.

private void handleRoot(RoutingContext routingContext) {
    HttpServerResponse response = routingContext.response();

    // Set the content type header
    response.putHeader("Content-Type", "text/html");

    // Send HTML content as the response
    response.end("<html><body><h1>Welcome to your Vert.x v2.0 application!</h1></body></html>");
}

Commit the changes in the git repository.

[student@workstation vertx-site]$ git commit -am "Modify the application version"
[master c46b365] Modify the application
 Committer: Student User <student@workstation.lab.example.com>
...output omitted...

Push the changes to the remote git server. Use the developer user with the developer password.

[student@workstation vertx-site]$ git push
Username for 'https://git.ocp4.example.com': developer
Password for 'https://developer@git.ocp4.example.com': developer
warning: redirecting to https://git.ocp4.example.com/developer/DO288-apps.git/
Enumerating objects: 24, done.
Counting objects: 100% (24/24), done.
Delta compression using up to 2 threads
Compressing objects: 100% (11/11), done.
Writing objects: 100% (23/23), 3.74 KiB | 1.87 MiB/s, done.
Total 23 (delta 2), reused 0 (delta 0), pack-reused 0
To https://git.ocp4.example.com/developer/DO288-apps
   b3c0f36..22ed9d5  master -> master

Note

Git might prompt for credentials by opening a desktop window. If you prefer to enter the credentials in the terminal, then close the window.

Rebuild the application and follow the build logs.

[student@workstation vertx-site]$ oc start-build --follow bc/vertx-site
build.build.openshift.io/vertx-site-2 started
Adding cluster TLS certificate authority to trust store
...output omitted...

Verify application functionality by opening the vertx-site-builds-applications.apps.ocp4.example.com URL in a web browser.

Finish

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 builds-applications

Discuss Red Hat OpenShift Developer II: Building and Deploying Cloud-native Applications

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Red Hat OpenShift Developer II: Building Kubernetes Applications (DO288)

Haley_Ruccio

31 lip 2023

Design, build, and deploy containerized applications on Red Hat OpenShiftRed Hat OpenShift Developer II: Building Kubernetes Applications (DO288) teaches you how to design, build, and deploy containerized software applications on an OpenShift clusterWhether you are migrating existing applications or writing container-native applications, you will learn how to boost developer productivity powered by Red Hat® OpenShift Container Platform, a containerized application platform that allows enterprises to manage container deployments and scale their applications using Kubernetes.This course is based on Red Hat OpenShift Container Platform 4.10.Course content summaryDesign containerized applications for OpenShift.Manage and trigger application builds using Source-to-Image (S2I).Customize an existing source-to-image base image.Deploy multi-container applications using Helm Charts.Create health checks to monitor and improve application reliability.Create and deploy cloud-native applications on OpenShift.Audience for this courseEnterprise application developersDevOps site reliability engineersRecommended for this courseTake our free assessment to gauge whether this offering is the best fit for your skills.View the Red Hat OpenShift skill paths.Complete Red Hat OpenShift I: Containers & Kubernetes (DO180), or have equivalent knowledgeBeing a Red Hat Certified System Administrator or having earned a higher certification is helpful for navigation and usage of the command line, but is not requiredTechnology considerationsThis course uses a lab environment provisioned in the Red Hat Online Learning (ROL) cloud.Internet access is required to run the exercises and labs.

Welcome to the Red Hat OpenShift Developer II (DO288) group in the Red Hat Learning Community!

Deanna

31 lip 2023

We are excited to launch a space dedicated to the Red Hat Training course DO288! To gain the most value from this group - click the "Join Group" button in the upper right hand corner.We encourage group members to collaborate in this group to discuss topics, ask questions, share best practices and tips, provide course feedback, and share their accomplishments as it relates to DO288.Read more about Red Hat OpenShift Developer II: Building Kubernetes Applications here.

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Revision: do288-4.12-0d49506