How to use org.keycloak.subsystem.server.extension

ServerUtil(ModelNode operation) {
  this.deploymentName = getDeploymentName(operation);
  this.subsysModule = findSubsysModule();
  this.serverWar = findServerWarUri();
}

protected KeycloakSubsystemDefinition() {
  super(KeycloakExtension.PATH_SUBSYSTEM,
    KeycloakExtension.getResourceDescriptionResolver("subsystem"),
    KeycloakSubsystemAdd.INSTANCE,
    KeycloakSubsystemRemoveHandler.INSTANCE
  );
}

static void addStepToRedeployServerWar(OperationContext context, String deploymentName) {
  addDeploymentAction(context, REDEPLOY, deploymentName);
}

@Override
protected void performRemove(OperationContext context, ModelNode operation, ModelNode model) throws OperationFailedException {
  String deploymentName = ServerUtil.getDeploymentName(operation);
  KeycloakAdapterConfigService.INSTANCE.setWebContext(null);
  if (requiresRuntime(context)) { // don't do this on a domain controller
    addStepToRemoveServerWar(context, deploymentName);
  }
  super.performRemove(context, operation, model);
}

@Override
protected void finishModelStage(OperationContext context, ModelNode operation, String attributeName, ModelNode newValue, ModelNode oldValue, Resource model) throws OperationFailedException {
  if (!context.isNormalServer() || attribNotChanging(attributeName, newValue, oldValue)) {
    super.finishModelStage(context, operation, attributeName, newValue, oldValue, model);
    return;
  }
  String deploymentName = ServerUtil.getDeploymentName(operation);
  if (attributeName.equals(KeycloakSubsystemDefinition.WEB_CONTEXT.getName())) {
    KeycloakAdapterConfigService.INSTANCE.setWebContext(newValue.asString());
    ServerUtil.addStepToRedeployServerWar(context, deploymentName);
  }
  super.finishModelStage(context, operation, attributeName, newValue, oldValue, model);
}

  @Override
  protected void execute(DeploymentProcessorTarget processorTarget) {
    processorTarget.addDeploymentProcessor(SUBSYSTEM_NAME, Phase.DEPENDENCIES, 0, new KeycloakProviderDependencyProcessor());
    processorTarget.addDeploymentProcessor(SUBSYSTEM_NAME,
        Phase.POST_MODULE, // PHASE
        Phase.POST_MODULE_VALIDATOR_FACTORY - 2, // PRIORITY
        new KeycloakProviderDeploymentProcessor());
    processorTarget.addDeploymentProcessor(SUBSYSTEM_NAME,
        Phase.POST_MODULE, // PHASE
        Phase.POST_MODULE_VALIDATOR_FACTORY - 1, // PRIORITY
        new KeycloakServerDeploymentProcessor());
  }
}, OperationContext.Stage.RUNTIME);

ModelNode getConfig() {
  ModelNode copy = fullConfig.clone();
  //System.out.println("******** BEFORE *************");
  //System.out.println(copy);
  //System.out.println("*****************************");
  copy.remove("web-context");
  massageScheduledTaskInterval(copy);
  massageMasterRealm(copy);
  massageTheme(copy);
  massageSpis(copy);
  //System.out.println("******** JSON *************");
  //System.out.println(copy.resolve().toJSONString(false));
  //System.out.println("**********************");
  return copy;
}

  @Override
  protected void execute(DeploymentProcessorTarget processorTarget) {
    processorTarget.addDeploymentProcessor(SUBSYSTEM_NAME,
        Phase.POST_MODULE, // PHASE
        Phase.POST_MODULE_VALIDATOR_FACTORY - 1, // PRIORITY
        new KeycloakServerDeploymentProcessor());
  }
}, OperationContext.Stage.RUNTIME);

/**
 * {@inheritDoc}
 */
@Override
public void writeContent(final XMLExtendedStreamWriter writer, final SubsystemMarshallingContext context) throws XMLStreamException {
  context.startSubsystemElement(KeycloakExtension.NAMESPACE, false);
  writeWebContext(writer, context);
  writer.writeEndElement();
}

private void readModules(final XMLExtendedStreamReader reader, ModelNode addThemeDefaults) throws XMLStreamException {
  while (reader.hasNext() && nextTag(reader) != END_ELEMENT) {
    MODULES.parseAndAddParameterElement(reader.getElementText(),addThemeDefaults, reader);
  }
}

  private boolean attribNotChanging(String attributeName, ModelNode newValue, ModelNode oldValue) {
    AttributeDefinition attribDef = KeycloakSubsystemDefinition.lookup(attributeName);
    if (!oldValue.isDefined()) {
      oldValue = attribDef.getDefaultValue();
    }
    if (!newValue.isDefined()) {
      newValue = attribDef.getDefaultValue();
    }
    return newValue.equals(oldValue);
  }
}

private void massageProviders(ModelNode spi) {
  if (!spi.hasDefined("provider")) return;
  ModelNode providers = spi.remove("provider");
  for (Property prop : providers.asPropertyList()) {
    ModelNode provider = prop.getValue();
    if (provider.has("properties")) {
      massageProviderProps(provider);
    }
    spi.get(prop.getName()).set(provider);
  }
}

@Override
protected void performRemove(OperationContext context, ModelNode operation, ModelNode model) throws OperationFailedException {
  String deploymentName = ServerUtil.getDeploymentName(operation);
  KeycloakAdapterConfigService.INSTANCE.setWebContext(null);
  if (requiresRuntime(context)) { // don't do this on a domain controller
    addStepToRemoveServerWar(context, deploymentName);
  }
  super.performRemove(context, operation, model);
}

@Override
protected void finishModelStage(OperationContext context, ModelNode operation, String attributeName, ModelNode newValue, ModelNode oldValue, Resource model) throws OperationFailedException {
  if (!context.isNormalServer() || attribNotChanging(attributeName, newValue, oldValue)) {
    super.finishModelStage(context, operation, attributeName, newValue, oldValue, model);
    return;
  }
  String deploymentName = ServerUtil.getDeploymentName(operation);
  if (attributeName.equals(KeycloakSubsystemDefinition.WEB_CONTEXT.getName())) {
    KeycloakAdapterConfigService.INSTANCE.setWebContext(newValue.asString());
    ServerUtil.addStepToRedeployServerWar(context, deploymentName);
  }
  super.finishModelStage(context, operation, attributeName, newValue, oldValue, model);
}

ServerUtil(ModelNode operation) {
  this.deploymentName = getDeploymentName(operation);
  this.subsysModule = findSubsysModule();
  this.serverWar = findServerWarUri();
}

protected KeycloakSubsystemDefinition() {
  super(KeycloakExtension.PATH_SUBSYSTEM,
    KeycloakExtension.getResourceDescriptionResolver("subsystem"),
    KeycloakSubsystemAdd.INSTANCE,
    KeycloakSubsystemRemoveHandler.INSTANCE
  );
}

static void addStepToRedeployServerWar(OperationContext context, String deploymentName) {
  addDeploymentAction(context, REDEPLOY, deploymentName);
}

protected SpiResourceDefinition() {
  super(PathElement.pathElement(TAG_NAME),
    KeycloakExtension.getResourceDescriptionResolver(TAG_NAME),
    SpiResourceAddHandler.INSTANCE,
    SpiResourceRemoveHandler.INSTANCE
  );
}

protected ThemeResourceDefinition() {
  super(PathElement.pathElement(TAG_NAME),
    KeycloakExtension.getResourceDescriptionResolver(TAG_NAME),
    ThemeResourceAddHandler.INSTANCE,
    ThemeResourceRemoveHandler.INSTANCE
  );
}

protected ProviderResourceDefinition() {
  super(PathElement.pathElement(TAG_NAME),
    KeycloakExtension.getResourceDescriptionResolver(TAG_NAME),
    ProviderResourceAddHandler.INSTANCE,
    ProviderResourceRemoveHandler.INSTANCE
  );
}