Backend routing

Route object

Syntax

Conditional expressions use SQL-like syntax:

$ParamName = 'value' and $AnotherParam = 'value'

Rules:

• Prefix each parameter with $. Reference any request parameter defined in the API (MAPPING or PASSTHROUGH mode).

• Combine expressions with and and or. Use parentheses () to control precedence.

• A non-existent parameter in a condition evaluates to false.

Supported data types:

System parameters

You can reference these built-in parameters without defining them in the API. If an API defines a parameter with the same name, the API parameter value takes precedence.

Expression examples

Route requests for APIs published to the test stage:

$CaStage = 'TEST'

Match a specific user from a specific IP address:

$UserName = 'Admin' and $CaClientIp = '47.47.XX.XX'

Match multiple AppIds over HTTPS:

$CaHttpScheme = 'HTTPS' and ($CaAppId = 1001 or $CaAppId = 1098 or $CaAppId = 2011)

Backend parameter reference

Configuration examples

HTTP

---
backend:
  type: HTTP
  address: "http://10.10.100.2:8000"
  httpTargetHostName: "a.b.com"
  path: "/users/{userId}"
  method: GET
  timeout: 7000

HTTP-VPC

---
backend:
  type: HTTP-VPC
  vpcAccessName: vpcAccess1
  vpcTargetHostName: "a.b.com"
  vpcScheme: "https"
  path: "/users/{userId}"
  method: GET
  timeout: 10000

Function Compute (FCEvent)

---
backend:
  type: FC
  fcRegion: cn-shanghai
  fcType: FCEvent
  serviceName: fcService
  functionName: fcFunction
  roleArn: "acs:ram::111111111:role/aliyunapigatewayaccessingfcrole"

Function Compute (HttpTrigger)

---
backend:
  type: FC
  fcRegion: cn-shenzhen
  method: GET
  fcType: HttpTrigger
  fcUrl: https://1833848375796824.cn-shenzhen.fc.aliyuncs.com/2016-08-15/proxy/servicetest/fctest3/fctest3
  roleArn: acs:ram::1833848375796824:role/aliyunapigatewayaccessingfcrole

OSS

---
backend:
  type: OSS
  ossRegionId: cn-hangzhou
  bucketName: bucketName
  key: /objectName
  timeout: 10000
  action: putObject

MOCK

---
backend:
  type: MOCK
  mockResult: "mock resul sample"
  mockStatusCode: 200
  mockHeaders:
    - name: server
      value: mock
    - name: proxy
      value: GW

Route by application ID

Route VIP callers (AppId 10098 or 10099) to a dedicated virtual private cloud (VPC) backend:

---
routes:
  - name: Vip
    condition: "$CaAppId = 10098 or $CaAppId = 10099"
    backend:
      type: "HTTP-VPC"
      vpcAccessName: "slbAccessForVip"

Route by environment

Send all test-stage requests to a public test server:

---
routes:
  - name: Vip
    condition: "$CaStage = 'TEST'"
    backend:
      type: "HTTP"
      address: "https://test-env.foo.com"

Blue-green deployment

Split traffic 5%/95% between a beta server and a VPC production backend:

---
routes:
  - name: BlueGreenPercent05
    condition: "1 = 1"
    weight: 5
    backend:
      type: "HTTP"
      address: "https://beta-version.api.foo.com"
      path: "/web/cloudapi"
    constant-parameters:
      - name: x-route-blue-green
        location: header
        value: "route-blue-green"
  - name: BlueGreenPercent95
    condition: "1 = 1"
    weight: 95
    backend:
      type: HTTP-VPC
      path: "/web/cloudapi"
      vpcAccessName: testvpc

condition: "1 = 1" always matches. condition: "1 = 0" never matches. Use weight to control traffic distribution between matching routes.