Merge pull request #476 from paketo-buildpacks/document-cds-training

Document CDS_TRAINING_JAVA_TOOL_OPTIONS

README.md

@@ -49,6 +49,7 @@ The buildpack will do the following:
 | `$BP_SPRING_AOT_ENABLED`              | Whether to contribute `$BPL_SPRING_AOT_ENABLED` at runtime. Beware that the Spring Boot app needs to have been AOT instrumented (presence of `META-INF/native-image`) too. Defaults to false.                                                                           |
 | `$BPL_SPRING_AOT_ENABLED`             | Whether to contribute `-Dspring.aot.enabled=true` to `JAVA_TOOL_OPTIONS` at runtime. Defaults to yes if the above conditions were met; false otherwise                                                                                                                  |                                                                                                           
 | `$BP_JVM_CDS_ENABLED`                 | Whether to perform the CDS training run (that will generate the caching file `application.jsa`). Defaults to false.                                                                                                                                                     |
+| `$CDS_TRAINING_JAVA_TOOL_OPTIONS`     | Allow the user to override the default `JAVA_TOOL_OPTIONS`, only for the CDS training run. Useful to configure your app not to reach external services during training run for example.                                                                                 |
 | `$BPL_JVM_CDS_ENABLED`                | Whether to load the CDS caching file (`-XX:SharedArchiveFile=application.jsa`) that was generated during the CDS training run. Defaults to the value of `BP_JVM_CDS_ENABLED`                                                                                            |
 ## Bindings
 The buildpack optionally accepts the following bindings: