Overview

RESTCONF is a network configuration management protocol that uses HTTP methods, including OPTIONS, HEAD, GET, POST, PATCH, PUT and DELETE, to provide a set of Create, Read, Update, Delete (CRUD) operations on YANG-defined datastore to manage network devices.

RESTCONF is developed based on the integration of NETCONF and HTTP protocols, which can be implemented on a device that supports the NETCONF protocol.

RESTCONF provides a programming interface in line with the popular RESTful style, providing users with the ability to efficiently develop Web-based operation and maintenance tools.

RESTCONF Components

As shown in Figure 1, the RESTCONF protocol consists of two parts: RESTCONF Client and Server.

• RESTCONF Client

The client utilizes the RESTCONF protocol for system management of network devices. The client sends HTTP requests to the server to create, delete, modify or query one or more data, encoded in XML or JSON format.

• RESTCONF Server

The server device is used to maintain the information data of the managed devices. When receiving a HTTP request from the RESTCONF client, the server parses and processes the request message, and then returns a response to the client.

Figure 1.     RESTCONF Components

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The information that the client obtains from the running server includes configuration data and status data.

• The client can query the status data and the configuration data.

• The client can modify the configuration data and manipulate it to achieve the desired state of the server.

• The client cannot modify the status data, which mainly includes the running status and statistical information of the server.

Advantage

• RESTCONF provides RESTful style programming interface to support Web development.

• Adopting XML or JSON encoding.

• Standardized interface, compatible with devices from multiple manufacturers, can reduce development and maintenance costs.

• Good extensibility, different manufacturer devices can define their own protocol operation.

YANG Model

Same as NETCONF, RESTCONF also works based on YANG.

Most YANG files independent of the device type are placed in the following path:

/pica/etc/common/data-models.

The yang files related to the device type are placed in the following path. This path contains a soft link to the yang file above, use an ellipsis instead.

Authentication

RESTCONF supports setting authorization to “Basic Auth”, the username and password should be set to the same as the accounts used for authentication of the RESTCONF server.

In the HTTPs request message sent by the client, you need to fill in the authentication information correctly to ensure that the connection between the RESTCONF client and server can be established successfully.

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HTTP Status Code

RESTCONF uses the Status-Line part of an HTTP response message to inform clients of their request’s result. HTTP defines these standard status codes that can be used to convey the results of a client’s request.

Table 1. HTTP status codes

RESTCONF Error Codes

The tree of YANG model <errors> is defined as follows:

When an error occurs, the server returns a response message carried with above error information. 

• error-type

The value of error-type can be：

• error-tag

• error-app-tag: Indicates a specific error type.

• error-path: Represents the location where the error occurred.

• error-message: Indicates detailed error information.

• error-info: Indicates the description of error parameters.

For example,

• Example 1: Input an error path when using GET method causes error: "error-type": "application".

The response result is:

• Example 2: Input a non-exist path when using PATCH method causes error: "error-type": "protocol".

The response result is:

• Example 3: No data was provided when using PUT method causes error: "error-type": "rpc".

The response result is: