@Override
    public boolean update(ApiClient apiClient, V1ConfigMap resource, String namespace) throws HyscaleException {
        if(resource==null){
            LOGGER.debug("Cannot update null ConfigMap");
            return false;
        }
        CoreV1Api coreV1Api = new CoreV1Api(apiClient);
        String name = resource.getMetadata().getName();
        V1ConfigMap existingConfigMap = null;
        try {
            existingConfigMap = get(apiClient, name, namespace);
        } catch (HyscaleException ex) {
            LOGGER.debug("Error while getting ConfigMap {} in namespace {} for Update, creating new", name, namespace);
            V1ConfigMap configMap = create(apiClient, resource, namespace);
            return configMap != null;
        }
        WorkflowLogger.startActivity(DeployerActivity.DEPLOYING_CONFIGMAP);
        try {
            String resourceVersion = existingConfigMap.getMetadata().getResourceVersion();
            resource.getMetadata().setResourceVersion(resourceVersion);
            coreV1Api.replaceNamespacedConfigMap(name, namespace, resource, DeployerConstants.TRUE, null, null);
        } catch (ApiException e) {
            HyscaleException ex = new HyscaleException(e, DeployerErrorCodes.FAILED_TO_UPDATE_RESOURCE,
                    ExceptionHelper.getExceptionMessage(getKind(), e, ResourceOperation.UPDATE));
            LOGGER.error("Error while updating ConfigMap {} in namespace {}, error {}", name, namespace, ex.toString());
            WorkflowLogger.endActivity(Status.FAILED);
            throw ex;
        }
        LOGGER.info("Updated ConfigMap {} in namespace {}", name, namespace);
        WorkflowLogger.endActivity(Status.DONE);
        return true;
    }
Fetch from cluster, populate required field in resource call update
deployer/deployer-services/src/main/java/io/hyscale/deployer/services/handler/impl/V1ConfigMapHandler.java