The conditional routing plugin can forward different client requests to different backend addresses based on the request and system parameter values. It is widely used in scenarios such as grayscale release, blue-green deployment, and tenant routing.
2. Click Plugin on the left sidebar to open the plugin list page.
3. Click Create in the top-left corner of the page and select Conditional Routing as the plugin type to create a conditional routing plugin.
You can create up to 10 routing policies in a conditional routing plugin and need to enter the following content in each policy:
Parameter
Required
Description
Policy name
Yes
Current policy name, which can contain up to 50 characters and must be unique in the same plugin.
Weight
Yes
Priority for policy match. You can enter a positive integer between 0 and 100. If it is not set, it will be 0 by default.
The greater the weight, the higher the match priority. For policies with the same weight, the later the creation time, the higher the priority.
Trigger condition
Yes
Conditional expression that judges whether the client request meets the condition. For more information, see the relevant description below.
Backend type
Yes
Public network URL/IP, VPC resources, SCF, Mock, and TSF are supported.
Backend configuration
Yes
Backend to which the client request will be forwarded if the request meets the condition. Enter the backend configuration in YAML format.
Step 2. Bind an API and make the plugin effective
1. Select the just created plugin in the list and click Bind API in the Operation column.
2. In the Bind API pop-up window, select the service, environment, and the API to which the plugin needs to be bound.
3. Click OK to bind the plugin to the API. At this time, the configuration of the plugin has taken effect for the API.
Conditional Expression Writing Guide
Parameter description
A conditional expression supports the following two types of parameters:
Request parameter in a certain location: Currently, only Header, Path, and Query parameters are supported.
If the a parameter in the Header location is configured in the frontend configuration, you can use header.a to represent this parameter in the plugin.
The Path parameter has no parameter name and is therefore represented by a path; for example, path='/test' indicates that the condition is met if the request path is /test.
The value definition of the Path parameter must start with /, such as '/test'.
You can use sysparam to reference system parameters of the current request without defining them in the API; however, if you define a parameter with the same name in the API, the value in the API will be overwritten by the value of the custom parameter. We recommend you enter the parameter value in lower camel case and make it case-insensitive. The following system parameters can be used in the routing plugin:
sysparam.clientIp: Client IP.
sysparam.httpScheme: Request protocol, which is HTTP or HTTPS.
sysparam.clientUa: UserAgent field uploaded by the client.
Note:
The parameter location is case-insensitive, while the parameter name is case-sensitive; for example, in the above header.a parameter, the parameter location header is case-insensitive, while the parameter name a is case-sensitive.
A conditional expression supports the following constant types:
Constant Type
Description
Example
STRING
String
Double and single quotation marks are supported, such as "Hello" and 'hello'
INTEGER
Integer
1001, -1
NUMBER
Floating point
0.1, 100.0
BOOLEAN
Boolean
true, false
Writing rules
You can use and and or to concatenate different expressions.
You can use parentheses () to specify the priority for condition match.
As a built-in function, Random() can generate a floating point parameter where the value is in NUMBER data type and ranges from 0 to 1 for random judgment.
If a nonexistent parameter such as param.unknown = 1 is used in the expression, false will be returned.
You can use the regular expression function regex() to match the parameter value, for example, regex(query.name,"colou?r"). You need to enclose the string in the regular expression with single or double quotation marks.
You can use the exists() function to specify whether a parameter exists, for example, exists(header.Accept).
Both == and = can be used to judge the "equal to" relationship.
Sample conditional expressions
The result is true with a probability of 5%: Random() < 0.05
UserName in the custom Header parameter is Admin, and the source IP is 47.47.74.77: header.UserName = 'Admin' and sysparam.clientIp = '47.47.74.77'
The user ID (a parameter in Header) of the current request is 1001, 1098, or 2011, and the request uses the HTTPS protocol: sysparam.httpScheme = 'https' and (header.id = 1001 or header.id = 1098 or header.id = 2011)
Backend Configuration Writing Guide
You can enter the configuration of the backend connected to public network URL/IP, VPC resources, SCF, Mock, and TSF:
The backend configuration must be in the YAML format.
The fields in the backend configuration are in one to one correspondence to the fields in the CreateApi API.
The conditional routing plugin creation page lists the demo configuration code for each type of backend. You can configure the backend simply by modifying the parameter values.
Backend connection to public network URL/IP
ServiceConfig:
Method: GET
Path: /test
Url:'http://test.com'
ServiceType: HTTP
Backend connection to VPC resources
ServiceConfig:
Method: GET
Path: /test
Url:'http://test.com'
UniqVpcId: vpc-xxxxx
Product: clb
ServiceType: HTTP
Backend connection to SCF
ServiceScfFunctionName: scftest
ServiceScfFunctionNamespace: mynamespace
ServiceScfFunctionQualifier: $DEFAULT
ServiceScfFunctionType: EVENT
ServiceScfIsIntegratedResponse:false
ServiceType: SCF
Backend connection to Mock
ServiceMockReturnMessage: hello mock from strategy
ServiceType: MOCK
Backend connection to TSF
X-MicroService-Name: consumer-demo
X-NameSpace-Code: mytsf
MicroServices:
-ClusterId: cls-xxxxxx
MicroServiceName: tsf-demo
NamespaceId: namespace-xxxxxx
ServiceConfig:
Method: ANY
Path: /xxxx
Url:''
ServiceTsfHealthCheckConf:
IsHealthCheck:true
ServiceTsfLoadBalanceConf:
IsLoadBalance:true
Method: RoundRobinRule
SessionStickRequired:false
ServiceType: TSF
pluginData
[
{
"strategy_name":"route-to-http",// Policy name, which can contain up to 50 letters, digits, and special symbols (%~_\\-.{}?&=) and must be unique in the same plugin
"strategy_weight":2,// Priority for policy match. You can enter a positive integer between 0 and 100. If it is not set, it will be 0 by default
"condition":"query.age<30 and query.need_verify=false or query.level>3",// Conditional expression
"backend_type":"HTTP",// Type of the backend for routing and forwarding. Valid values: MOCK, HTTP, SCF, VPC, UPSTREAM, TSF
"backend_config":{// Backend configuration
"ServiceConfig":{
"Method":"GET",
"Path":"/v1/bpi/currentprice.json",
"Url":"https://api.coindesk.com"
},
"ServiceType":"HTTP"
}
}
]
Notes
If a request cannot match a routing policy configured in the conditional routing plugin bound to an API, it will be forwarded to the default API backend.
Yes
No
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