ExtensionChain

A single extension chain wrapper that contains the match conditions and extensions to execute.

JSON representation 
{
  "name": string,
  "matchCondition": {
    object (MatchCondition)
  },
  "extensions": [
    {
      object (Extension)
    }
  ]
}
Fields
name

string

Required. The name for this extension chain. The name is logged as part of the HTTP request logs. The name must conform with RFC-1034, is restricted to lower-cased letters, numbers and hyphens, and can have a maximum length of 63 characters. Additionally, the first character must be a letter and the last a letter or a number.
matchCondition

object (MatchCondition)

Required. Conditions under which this chain is invoked for a request.
extensions[]

object (Extension)

Required. A set of extensions to execute for the matching request. At least one extension is required. Up to 3 extensions can be defined for each extension chain for LbTrafficExtension resource. LbRouteExtension chains are limited to 1 extension per extension chain.

MatchCondition

Conditions under which this chain is invoked for a request.

JSON representation 
{
  "celExpression": string
}
Fields
celExpression

string

Required. A Common Expression Language (CEL) expression that is used to match requests for which the extension chain is executed.

Extension

A single extension in the chain to execute for the matching request.

JSON representation 
{
  "name": string,
  "authority": string,
  "service": string,
  "supportedEvents": [
    enum (EventType)
  ],
  "timeout": string,
  "failOpen": boolean,
  "forwardHeaders": [
    string
  ]
}
Fields
name

string

Required. The name for this extension. The name is logged as part of the HTTP request logs. The name must conform with RFC-1034, is restricted to lower-cased letters, numbers and hyphens, and can have a maximum length of 63 characters. Additionally, the first character must be a letter and the last a letter or a number.
authority

string

Required. The :authority header in the gRPC request sent from Envoy to the extension service.
service

string

Required. The reference to the service that runs the extension. Must be a reference to a backend service.
supportedEvents[]

enum (EventType)

Optional. A set of events during request or response processing for which this extension is called. This field is required for the LbTrafficExtension resource. It's not relevant for the LbRouteExtension resource.
timeout

string (Duration format)

Required. Specifies the timeout for each individual message on the stream. The timeout must be between 10-1000 milliseconds.

A duration in seconds with up to nine fractional digits, ending with 's'. Example: "3.5s".
failOpen

boolean

Optional. Determines how the proxy behaves if the call to the extension fails or times out. When set to TRUE, request or response processing continues without error. Any subsequent extensions in the extension chain are also executed. When set to FALSE: * If response headers have not been delivered to the downstream client, a generic 500 error is returned to the client. The error response can be tailored by configuring a custom error response in the load balancer.

  • If response headers have been delivered, then the HTTP stream to the downstream client is reset. Default is FALSE.
forwardHeaders[]

string

Optional. List of the HTTP headers to forward to the extension (from the client or backend). If omitted, all headers are sent. Each element is a string indicating the header name.

EventType

Defines the part of the request or response for which this extension is called. The valid values are: REQUEST_HEADERS, REQUEST_BODY, RESPONSE_HEADERS, RESPONSE_BODY.

Enums
EVENT_TYPE_UNSPECIFIED Unspecified value. Do not use.
REQUEST_HEADERS If included in supportedEvents, the extension is called when the HTTP request headers arrive.
REQUEST_BODY If included in supportedEvents, the extension is called when the HTTP request body arrives.
RESPONSE_HEADERS If included in supportedEvents, the extension is called when the HTTP response headers arrive.
RESPONSE_BODY If included in supportedEvents, the extension is called when the HTTP response body arrives.