API Guide

Header Description

ETag Supported on AccountService, FirmwareInventory, and metadata URIs.

Location Service sets this header when resources are created or when HTTP requests are redirected to other resources.

Cache-Control Returned on all responses. Metadata URIs support cached responses. Instrumentation resources cannot be

cached.

X-Auth-Token Used for authentication of user sessions. See “Session-based authentication” under Redfish authentication and

authorization on page 10.

HTTP status codes and error messages

HTTP defines the status codes that are returned in response messages. When the HTTP status code indicates a failure, the response

body contains an extended error resource, which provides meaningful and deterministic error semantics.

The extended-error information for the Redfish service that Dell has implemented contains error or exception information that is unique to

Dell. This information provides more details and recommendations for error resolution. To learn more about extended-error information,

see the Event and Error Message Reference Guide available at www.dell.com/manuals.

For more details about the error messages, see the following:

• Base messages: Registries > BaseMessage schema. Examples of base messages are GeneralError, PropertyUnknown,

InsufficientPrivilege, and so on.

• Event and Error messages: Registries > Message schema. Examples of Event and Error messages are AMP0300, ASR0001,

HWC7014, and so on.

For more information about supported status codes and error messages, see the Redfish Scalable Platforms Management API

Specification document available at www.dmtf.org/standards/redfish.

NOTE:

• For some URLs, if you execute an unsupported method, the response code may not indicate that the method is

unsupported. To see the methods that the URL supports, see the relevant section in this document. You can also use

the Get method on the URL and see the supported methods in the response.

• If you perform a Patch operation on multiple attributes, and if some attributes do not get updated due to

dependency issues, HTTP code 400 is returned.

SSL certificates of iDRAC

iDRAC includes a web server that uses the industry-standard SSL security protocol to transfer encrypted data over a network. Built upon

asymmetric encryption technology, SSL is widely accepted for providing authenticated and encrypted communication between clients and

servers to prevent eavesdropping across a network.

By default, the iDRAC web server has a Dell self-signed SSL digital certificate. Redfish service reuses this certificate installed on the

iDRAC web server. You can replace the default SSL certificate with a certificate signed by a well-known Certificate Authority (CA). You

can replace SSL certificates using the iDRAC interfaces such as web interface, RACADM, or WSMan. For more information on managing

SSL certificates of iDRAC, see the latest iDRAC User’s Guide available at Dell.com/idracmanuals.

Eventing

The Redfish service generates asynchronous notifications (events) that are defined by Redfish subscription for the eventing service.

These events are sent to an event destination by using HTTP POST method. Events are generated when some significant change or error

condition typically of time critical nature occurs. When an event occurs on the service, it notifies the clients. Redfish service must be

enabled and iDRAC must be configured to create event subscriptions and to gain read-only privilege for viewing event subscriptions.

The iDRAC implementation of a Redfish service supports only HTTPS notifications. In certain situations, iDRAC may not be able to verify

certificates sent by a peer. To handle such situations, iDRAC can be configured to skip certificate verification by using the attribute

iDRAC.RedfishEventing.IgnoreCertificateErrors. This attribute can be configured to True or False (Default) using

RACADM or the WS-MAN interface. Set this attribute to True if certificate validation is not required.

Redfish service provides Lifecycle and Alert events. Lifecycle events may occur when resources are created, modified, or destroyed. Alert

events occur when a resource needs to indicate a significant event. Alert events may be either directly or indirectly pertaining to the

Redfish-based systems management