Do not require Gradle to be installed to generate the Gradle wrapper

[gastaldi]

Description
When mvn quarkus:create -DbuildTool=gradle is invoked and Gradle isn't installed in the local environment, the Gradle wrapper is not created.

Implementation ideas
Do not require Gradle to be installed. Copy files manually as done in code.quarkus.io.

[ShubhamRwt]

@gastaldi Hello. I was of thinking of starting working on this issue. Can you give me some more details regarding this issue.

[gastaldi]

@ShubhamRwt hello! Thanks for the interest in taking this.

If you create a new Gradle project and execute gradle wrapper, you'll see the files that need to be added.

I think one solution when Gradle isn't available in the environment is to copy the files manually when the project is generated. To have them you'll need to add them (probably in the quarkus-platform-descriptor-json build) by changing the pom.xml to execute gradle wrapper, so you don't really need to commit the files in the repository

[ShubhamRwt]

@gastaldi Should we keep the files bundled in the code or should we write a code that makes a request to download gradle wrapper files when needed during setup.

[gastaldi]

@ShubhamRwt keeping the files bundled in the code is better to avoid network trips.

[gastaldi]

Just make sure it is dynamically generated during the quarkus build

[ShubhamRwt]

@gastaldi I did some research on this issue. I guess we would need to use pom itself to generate gradle wrapper but for that we might require some external dependency.

[glefloch]

@ShubhamRwt I started looking at this last week.
As @gastaldi said, we can run gradle wrappercommand in the platform-descriptor-json pom.xml. This can be done using the exec-maven-plugin plugin.

Then in the CreateProjectMojo mojo, If an exception occurred while generating the Gradle wrapper, we can fallback to a copy from the platform descriptor.

[ShubhamRwt]

Yes @glefloch , just had the same idea. I got a chunk of code regarding that

<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<executions>
    <execution>
        <id>gradle</id>
        <phase>prepare-package</phase>
        <configuration>
            <executable>${gradle.executable}</executable>
            <arguments>
                <argument>clean</argument>
                <argument>build</argument>
                <argument>-Pgroup=${project.groupId}</argument>
                <argument>-Pversion=${project.version}</argument>
                <argument>-S</argument>
            </arguments>
        </configuration>
        <goals>
            <goal>exec</goal>
        </goals>
    </execution>
</executions>

But I am not sure if I am headed in the right direction or not.

[glefloch]

Yes, actually, the gradle wrapper is generated, using the gradle wrapper task.
This will generate gardlew.sh, gradlew.bat files and some others.
Those files can be added into the plateform-descriptor-json artifact. The xml would looks like:

<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<executions>
<execution>
    <id>gradle</id>
    <phase>prepare-package</phase>
    <configuration>
        <executable>gradle</executable>
        <arguments>
            <argument>wrapper</argument>
        </arguments>
    </configuration>
    <goals>
        <goal>exec</goal>
    </goals>
 </execution>
</executions>

Then, in the CreateProjectMojo, if the createGradleWrapper method fails, gradle wrapper file should be copied from the plateform-descriptor-json.