Using Gradle artifact repositories

This section describes how to download and configure Gradle.

Downloading different versions of Gradle

The recommended way to download any version of Gradle is by using the Gradle Wrapper script. If your project does not have a gradle/wrapper directory, run $ gradle wrapper to configure the Wrapper.

Prerequisites

  • The Gradle Wrapper is available in your project.

Procedure

To download a Gradle version from a non-standard location, change your Wrapper settings in /projects/<your_project>/gradle/wrapper/gradle-wrapper.properties:

  • Change the distributionUrl property to point to a URL of the Gradle distribution ZIP file:

    properties
distributionUrl=http://<url_to_gradle>/gradle-6.1-bin.zip

Alternatively, you may place a Gradle distribution zip file locally in /project/gradle in your workspace.

  • Change the distributionUrl property to point to a local address of the Gradle distribution zip file:

    properties
distributionUrl=file\:/projects/gradle/gradle-6.1-bin.zip

Configuring global Gradle repositories

Use an initialization script to configure global repositories for the workspace. Gradle performs extra configuration before projects are evaluated, and this configuration is used in each Gradle project from the workspace.

Procedure

To set global repositories for Gradle that could be used in each Gradle project in the workspace, create an init.gradle script in the ~/.gradle/ directory:

allprojects {
  repositories {
    mavenLocal ()
    maven {
      url "http://repo.mycompany.com/maven"
      credentials {
        username "admin"
        password "my_password"
      }
    }
  }
}

This file configures Gradle to use a local Maven repository with the given credentials.

The ~/.gradle directory does not persist in the current Java plug-in versions, so you must create the init.gradle script at each workspace start in the Java plug-in sidecar container.

Using self-signed certificates in Gradle projects

Internal artifact repositories often do not have a certificate signed by an authority that is trusted by default in Java. They are mainly signed by an internal company authority or are self-signed. Configure your tools to accept these certificates by adding them to the Java truststore.

Procedure

  1. Obtain a server certificate file from the repository server. It is customary for administrators to provide certificates of internal artifact servers as Kubernetes secrets (see Importing untrusted TLS certificates to Che). The relevant server certificates will be mounted in /public-certs in every container in the workspace.

    1. Copy the original Java truststore file:

      $ mkdir /projects/maven
$ cp $JAVA_HOME/lib/security/cacerts /projects/maven/truststore.jks
$ chmod +w /projects/maven/truststore.jks

    2. Import the certificate into the Java truststore file

      $ keytool -import -noprompt -file /public-certs/nexus.cer -alias nexus -keystore /projects/maven/truststore.jks -storepass changeit
Certificate was added to keystore

    3. Upload the truststore file to /projects/gradle/truststore.jks to make it available for all containers.

  2. Add the truststore file in the Gradle container.

    1. Add the javax.net.ssl system property to the JAVA_OPTS environment variable:

        - mountSources: true
    alias: maven
    type: dockerimage
    ...
    env:
       -name: JAVA_OPTS
        value: >-
          -Duser.home=/projects/gradle
          -Djavax.net.ssl.trustStore=/projects/maven/truststore.jks
          -Djavax.net.ssl.trustStorePassword=changeit
Additional resources