2.8. Using devfiles in odo
Creating applications by using devfiles with `odo` is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see https://access.redhat.com/support/offerings/techpreview/.
2.8.1. About the devfile in odo
The devfile is a portable file that describes your development environment. With the devfile, you can define a portable developmental environment without the need for reconfiguration.
With the devfile, you can describe your development environment, such as the source code, IDE tools, application runtimes, and predefined commands. To learn more about the devfile, see the devfile documentation.
With odo, you can create components from the devfiles. When creating a component by using a devfile, odo transforms the devfile into a workspace consisting of multiple containers that run on OpenShift Container Platform, Kubernetes, or Docker. odo automatically uses the default devfile registry but users can add their own registries.
2.8.2. Creating a Java application by using a devfile
2.8.3. Prerequisites
-
You have installed
odo. -
You must know your ingress domain cluster name. Contact your cluster administrator if you do not know it. For example,
apps-crc.testingis the cluster domain name for Red Hat CodeReady Containers. You have enabled Experimental Mode in
odo.-
To enable Experimental Mode in
odopreferences, runodo preference set Experimental trueor use the environment variableodo config set --env ODO_EXPERIMENTAL=true
-
To enable Experimental Mode in
2.8.3.1. Creating a project
Create a project to keep your source code, tests, and libraries organized in a separate single unit.
Procedure
Log in to an OpenShift Container Platform cluster:
$ odo login -u developer -p developer
Create a project:
$ odo project create myproject
Example output
✓ Project 'myproject' is ready for use ✓ New project created and now using project : myproject
2.8.3.2. Listing available devfile components
With odo, you can display all the components that are available for you on the cluster. Components that are available depend on the configuration of your cluster.
Procedure
To list available devfile components on your cluster, run:
$ odo catalog list components
The output lists the available
odocomponents:Odo Devfile Components: NAME DESCRIPTION REGISTRY java-maven Upstream Maven and OpenJDK 11 DefaultDevfileRegistry java-openliberty Open Liberty microservice in Java DefaultDevfileRegistry java-quarkus Upstream Quarkus with Java+GraalVM DefaultDevfileRegistry java-springboot Spring Boot® using Java DefaultDevfileRegistry nodejs Stack with NodeJS 12 DefaultDevfileRegistry Odo OpenShift Components: NAME PROJECT TAGS SUPPORTED java openshift 11,8,latest YES dotnet openshift 2.1,3.1,latest NO golang openshift 1.13.4-ubi7,1.13.4-ubi8,latest NO httpd openshift 2.4-el7,2.4-el8,latest NO nginx openshift 1.14-el7,1.14-el8,1.16-el7,1.16-el8,latest NO nodejs openshift 10-ubi7,10-ubi8,12-ubi7,12-ubi8,latest NO perl openshift 5.26-el7,5.26-ubi8,5.30-el7,latest NO php openshift 7.2-ubi7,7.2-ubi8,7.3-ubi7,7.3-ubi8,latest NO python openshift 2.7-ubi7,2.7-ubi8,3.6-ubi7,3.6-ubi8,3.8-ubi7,3.8-ubi8,latest NO ruby openshift 2.5-ubi7,2.5-ubi8,2.6-ubi7,2.6-ubi8,2.7-ubi7,latest NO wildfly openshift 10.0,10.1,11.0,12.0,13.0,14.0,15.0,16.0,17.0,18.0,19.0,20.0,8.1,9.0,latest NO
2.8.3.3. Deploying a Java application using a devfile
In this section, you will learn how to deploy a sample Java project that uses Maven and Java 8 JDK using a devfile.
Procedure
Create a directory to store the source code of your component:
$ mkdir <directory-name>
Create a component configuration of Spring Boot component type named
myspringand download its sample project:$ odo create java-spring-boot myspring --starter
The previous command produces the following output:
Experimental mode is enabled, use at your own risk Validation ✓ Checking devfile compatibility [195728ns] ✓ Creating a devfile component from registry: DefaultDevfileRegistry [170275ns] ✓ Validating devfile component [281940ns] Please use `odo push` command to create the component with source deployed
The
odo createcommand downloads the associateddevfile.yamlfile from the recorded devfile registries.List the contents of the directory to confirm that the devfile and the sample Java application were downloaded:
$ ls
The previous command produces the following output:
README.md devfile.yaml pom.xml src
Create a URL to access the deployed component:
$ odo url create --host apps-crc.testing
The previous command produces the following output:
✓ URL myspring-8080.apps-crc.testing created for component: myspring To apply the URL configuration changes, please use odo push
注意You must use your cluster host domain name when creating the URL.
Push the component to the cluster:
$ odo push
The previous command produces the following output:
Validation ✓ Validating the devfile [81808ns] Creating Kubernetes resources for component myspring ✓ Waiting for component to start [5s] Applying URL changes ✓ URL myspring-8080: http://myspring-8080.apps-crc.testing created Syncing to component myspring ✓ Checking files for pushing [2ms] ✓ Syncing files to the component [1s] Executing devfile commands for component myspring ✓ Executing devbuild command "/artifacts/bin/build-container-full.sh" [1m] ✓ Executing devrun command "/artifacts/bin/start-server.sh" [2s] Pushing devfile component myspring ✓ Changes successfully pushed to component
List the URLs of the component to verify that the component was pushed successfully:
$ odo url list
The previous command produces the following output:
Found the following URLs for component myspring NAME URL PORT SECURE myspring-8080 http://myspring-8080.apps-crc.testing 8080 false
View your deployed application by using the generated URL:
$ curl http://myspring-8080.apps-crc.testing
2.8.4. Converting an S2I component into a devfile component
With odo, you can create both Source-to-Image (S2I) and devfile components. If you have an existing S2I component, you can convert it into a devfile component using the odo utils command.
Procedure
Run all the commands from the S2I component directory.
Run the
odo utils convert-to-devfilecommand, which createsdevfile.yamlandenv.yamlbased on your component:$ odo utils convert-to-devfile
Push the component to your cluster:
$ odo push
注意If the devfile component deployment failed, delete it by running:
odo delete -aVerify that the devfile component deployed successfully:
$ odo list
Delete the S2I component:
$ odo delete --s2i
