Conditional Routing
If you have a native API that is hosted at two or more endpoints, you can use the condition-based protocol to route specific types of messages to specific endpoints. The requests are routed according to the condition-based routing rules you create. For example, if your entry protocol is HTTP or HTTPS, you can select conditional routing specifying HTTP or HTTPS. A routing rule specifies where requests should be routed to, and the criteria to use to route. You may also specify how to authenticate requests.
The following table provides the existing options of routing till webMethods API Gateway version 10.5 and their corresponding variable syntax to choose the same option in webMethods API Gateway version 10.11.
| 10.5 Conditional Variable | 10.5 Condition Operator | 10.11 Transformation Variable | 10.11 Transformation Condition Operator |
|---|---|---|---|
| Consumer | $\{request.application.id\} | Equals | |
| Date | Before After | $\{date\} | Lesser than Greater than |
| Time | Before After | $\{time\} | Lesser than Greater than |
| Predefined System Context Variables | |||
| Inbound HTTP Method | Not equal to | ${inboundHTTPMethod} | Not equals |
| Routing Method | ${routingMethod} | ||
| Inbound Content Type | ${inboundContentType} | ||
| Inbound Accept | ${inboundAccept} | ||
| Inbound Protocol | ${inboundProtocol} | ||
| Inbound Request URI | ${inboundRequestURI} | ||
| Inbound IP | ${inboundIP} | ||
| Gateway Hostname | ${gatewayHostname} | ||
| Gateway IP | ${gatewayIP} | ||
| Operation Name | ${operationName} | ||
| Custom Context Variables | |||
| mx:var1 | Equal to | ${var1} | Equals |
| PROTOCOL_HEADERS[KEY] | Not equal to | ${request.headers.KEY} | Not Equals |
| SOAP_HEADERS[INDEX] | Lesser than | ${soapHeaders[INDEX} | Lesser than |
| Greater than | Greater than | ||
| IPV4 | ${inboundIP} | Range | |
| IPV6 | ${inboundIP} | Range |
The table lists the properties that you can specify for this policy:
| Parameter | Description |
|---|---|
| Default Route To. Specifies the URLs of two or more native services in a pool to which the requests are routed. | |
| Endpoint URI | Specifies the URI of the native API endpoint to route the request to in case all routing
rules evaluate to False. Service registries that have been added to the webMethods API Gateway instance are
also included in the list. If you choose a service registry, webMethods API Gateway sends a request to the service registry to discover the IP address and port at which the native service is running. API Gateway replaces the service registry alias in the Endpoint URI with the IP address and port returned by the service registry. For example, if your service is hosted at the URL: http://hostname/abc/, you need to configure the Endpoint URI as: http://${ServiceRegistryName}/abc/. As this property supports variable framework, you can make use of the available variables. For example, you can configure the endpoint URI using hard coded URL, simple alias, endpoint alias, and variable syntax or any of these combination. If you define the endpoint URI as http://${myAliasHost}:${request.headers.nativeport}/${sys:resource-path}, where the ${myAliasHost} variable syntax is used to define the simple alias and the ${request.headers.nativeport} variable syntax is used to define the native port based on the request. For details about the variables available in webMethods API Gateway, see Variable Framework. Note: If you use endpoint alias, make sure the endpoint alias is created before you define it in the
policy. For example, if you define ${alias} syntax in the policy before creating the alias as
endpoint alias, webMethods API Gateway considers ${alias} as custom variable or simple alias and tries to
resolve against those. So in that case, after creating endpoint alias you have to edit and save the
API or policy to associate ${alias} syntax with the endpoint alias.
|
| HTTP Method | This is applicable to REST-based APIs. Specifies the available routing methods are GET, POST, PUT, DELETE, and CUSTOM (default). When CUSTOM is selected, the HTTP method in the incoming request is sent to the native service. When other methods are selected, the selected method is used in the request sent to the native service. Note: Use to achieve this as other transformations can also be done
under the same policy.
|
| SOAP Optimization Method | This is applicable for SOAP-based APIs. Specifies the optimization methods that API Gateway can use to parse SOAP requests to the native API. Select one of the following options:
|
| HTTP Connection Timeout (seconds) | Specifies the time interval (in seconds) after which a connection attempt times out. The precedence of the Connection Timeout configuration is as follows:
|
| Read Timeout (seconds) | Specifies the time interval (in seconds) after which a socket read attempt times out. The precedence of the Read Timeout configuration is as follows:
|
| Pass WS-Security Headers | This is applicable for SOAP-based APIs. Selecting this indicates that webMethods API Gateway should pass the WS-Security headers of the incoming requests to the native API. |
| SSL Configuration. Configures keystore, key alias, and truststore for securing connections to native APIs. | |
| Keystore Alias | Specifies the keystore alias configured in webMethods API Gateway. This value (along with the value of Client Certificate Alias) is used for performing SSL client authentication. Lists all available keystores. If you have not configured any keystore, the list is empty. |
| Key Alias | Specifies the alias for the private key, which must be stored in the keystore specified by the keystore alias. |
| Truststore Alias | Specifies the alias for the truststore that contains the list of CA certificates that API Gateway uses to validate the trust relationship with the native API. If you do not configure any truststore alias, it implies that webMethods API Gateway does not validate the certificates provided by native APIs. |
| Service Registry Configuration | |
| Service Discovery Endpoint Parameter | Values required for constructing the discovery service URI.
For example: if the service registry configuration of the service registry that you have
selected in Endpoint URI has Service discovery path
set to "/catalog/service/{serviceName}" (and the As the Value field supports variable framework, you can make use of the available variables as path parameters. For example, if you provide a parameter as {serviceName}( in Service discovery path while you define a service registry) and the corresponding values for the path parameter as ${request.header.var1}, the value in var1 retrieved from the request header substitutes the service name. For details about the variables available in API Gateway, see Variable Framework. |
| Rule. Defines the routing decisions based on one of the following routing options. | |
| Name | Provide a name for the rule. |
| Condition Operator | Specifies the condition operator to be used. Select one of the following operators:
|
| Add Condition | Specify the context variables for processing client requests.
For details about the variables available in webMethods API Gateway, see Variable Framework. |
| Route To. Specifies the endpoint URI of native services in a pool to which the requests are routed. | |
| Endpoint URI | Specifies the URI of the native API endpoint to route the request to. You can use service
registries in a similar manner as described in the main Endpoint URI
configuration section described earlier. For example, if your service is hosted at the URL: http://hostname/abc/, you need to configure the Endpoint URI as: http://${ServiceRegistryName}/abc/. As this property supports variable framework, you can make use of the available variables. For example, you can configure the endpoint URI using hard coded URL, simple alias, endpoint alias, and variable syntax or any of these combination. If you define the endpoint URI as http://${myAliasHost}:${request.headers.nativeport}/${sys:resource-path}, where the ${myAliasHost} variable syntax is used to define the simple alias and the ${request.headers.nativeport} variable syntax is used to define the native port based on the request. For details about the variables available in webMethods API Gateway, see Variable Framework . Note: If you use endpoint alias, make sure the endpoint alias is created before you define it in the
policy. For example, if you define ${alias} syntax in the policy before creating the alias as
endpoint alias, webMethods API Gateway considers ${alias} as custom variable or simple alias and tries to
resolve against those. So in that case, after creating endpoint alias you have to edit and save the
API or policy to associate ${alias} syntax with the endpoint alias.
|
| HTTP Method | This is applicable for REST-based APIs. Specifies the available routing methods are GET, POST, PUT, DELETE, and CUSTOM (default). When CUSTOM is selected, the HTTP method in the incoming request is sent to the native service. When other methods are selected, the selected method is used in the request sent to the native service. |
| Soap Optimization Method | This is applicable for SOAP-based APIs. Specifies values to enable SSL authentication for SOAP APIs. Select one of the following options:
|
| HTTP Connection Timeout (seconds) | Specifies the time interval (in seconds) after which a connection attempt times out. The precedence of the Connection Timeout configuration is as follows:
|
| Read Timeout (seconds) | Specifies the time interval (in seconds) after which a socket read attempt times out. The precedence of the Read Timeout configuration is as follows:
|
| Pass WS-Security Headers | This is applicable for SOAP-based APIs. Selecting this indicates that webMethods API Gateway should pass the WS-Security headers of the incoming requests to the native API. |
| SSL Configuration | Configures keystore, key alias, and truststore for securing connections to native APIs.
Provide the following information:
|
| Service Registry Configuration | |
| Service Discovery Endpoint Parameter | Values required for constructing the discovery service URI.
For example: if the service registry configuration of the service registry that you have
selected in Endpoint URI has Service discovery path
set to "/catalog/service/{serviceName}" (and the As the Value field supports variable framework, you can make use of the available variables as path parameters. For example, if you provide a parameter as {serviceName}( in Service discovery path while you define a service registry) and the corresponding values for the path parameter as ${request.header.var1}, the value in var1 retrieved from the request header substitutes the service name. For details about the variables available in API Gateway, see Variable Framework. |