How can i change and set the HTTP status Code ? I want to set HTTP status code based on my backend service response. Though my backend service is failed some reason(Say Ex:Invalid Request) and the backend service returns Service Error code, but Proxy returns default 200 Ok status code which i want to change based on status of backend service. how do i achieve that ? or what is best way to do that?
1 Like
Check out this similar question: https://community.apigee.com/questions/10879/response-flow-in-case-of-non-success-response-code.html
Will that solution work for your case?
If there is a difference between the successful response message and an error response message, you can use an extract variable policy and extract the values from the back end response and use a Raise Fault policy to raise an error with an appropriate http code when that variable is not null.
<Step>
<Name>fault-resource-not-found</Name>
<Condition>(responsePrefix.error != null)</Condition>
</Step>
In the above snippet, responsePrefix.error is the value extracted from the response we got from the backend.
And the fault something like
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<RaiseFault async="false" continueOnError="false" enabled="true" name="fault-missing-info">
<DisplayName>fault-missing-info</DisplayName>
<Properties/>
<FaultResponse>
<Set>
<Headers>
<Header name="Content-Type">application/json</Header>
</Headers>
<Payload contentType="application/json" variablePrefix="#" variableSuffix="%">
{
"errors":[
{
"code": "400",
"userMessage": "Missing Info",
"systemMessage": "Missing Info"
}
]
}
</Payload>
<StatusCode>400</StatusCode>
<ReasonPhrase>Bad Request</ReasonPhrase>
</Set>
</FaultResponse>
<IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
</RaiseFault>
As you see in the Raise fault policy, you can configure the response message, http code, etc via flow variables.
Hope this helps
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Thanks !! Does responsePrefix is predefined which reads from XML or JSON ? My output default variable is response.
No, responsePrefix is the Variable prefix I have on my ExtractVariable policy. You need to pass your response into the Extract Variable as Source and then use the extracted variable in the Condition.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ExtractVariables async="false" continueOnError="false" enabled="true" name="extract-baas-response">
<DisplayName>extract-response</DisplayName>
<Properties/>
<IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
<JSONPayload>
<Variable name="entities" type="nodeset">
<JSONPath>$.entities</JSONPath>
</Variable>
<Variable name="error" type="string">
<JSONPath>$.error</JSONPath>
</Variable>
<Variable name="error_description" type="string">
<JSONPath>$.error_description</JSONPath>
</Variable>
</JSONPayload>
<Source clearPayload="false">response</Source>
<VariablePrefix>responsePrefix</VariablePrefix>
</ExtractVariables>
After the above Extract policy is executed, responsePrefix.error will have a value when an error is sent from the target. Using that you can have a Condition in your flow
<Step>
<Name>resource-not-found</Name>
<Condition>(responsePrefix.error != null)</Condition>
</Step>
and Raise a Fault. In my case I am extracting the error_description also and using that when building the Fault policy custom payload. Something like this
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<RaiseFault async="false" continueOnError="false" enabled="true" name="resource-not-found">
<DisplayName>resource-not-found</DisplayName>
<Properties/>
<FaultResponse>
<Set>
<Headers>
<Header name="Content-Type">application/json</Header>
</Headers>
<Payload contentType="application/json" variablePrefix="#" variableSuffix="%">
{
"errors":[
{
"code": "Not Found",
"userMessage": "#responsePrefix.error%",
"systemMessage": "#responsePrefix.error_description%"
}
]
}
</Payload>
<StatusCode>404</StatusCode>
<ReasonPhrase>Not Found</ReasonPhrase>
</Set>
</FaultResponse>
<IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
</RaiseFault>
Hope this clarifies. Please accept if it does
That works !! But, i want set only Status Code. Because, My Service Errors are handled at transformation and displayed in UI. I would like to set only Status Code other than 200Ok. If i use Raise Fault before or after Raise Fault, my formatted error by xsl transformation is overwritten. Is that best to set only Bad Request with Status Code like 404 ?
Will this help ?
I followed this approach.
Step 1) Conditionally Checking and calling Assign Message Policy after my final transformed response.
<Step>
<Condition>responsePrefix.status == "Failed"</Condition>
<Name>AMBackend-Service-Fault</Name>
</Step>
Step 2) if condition satisfied then putting the response.content in Assign Message Policy like this.
But, not sure whether good recommended solution or not.
<Set>
<Headers>
<Header name="Content-Type">application/json</Header>
</Headers>
<Payload contentType="application/json" variablePrefix="@" variableSuffix="#">"@response.content#"</Payload>
<StatusCode>404</StatusCode>
<ReasonPhrase>Bad Request</ReasonPhrase>
</Set>
But, the above Approach the the response is not formatted as per JSON standard.
HI
I would recommend Raise Fault policy for any error responses instead of Assign Message. Change your AMBackend-Service-Fault policy to a Raise Fault policy - more details here
<FaultResponse>
<Set>
<StatusCode>404</StatusCode>
<ReasonPhrase>Bad Request</ReasonPhrase>
</Set>
</FaultResponse>
No need to set the payload
You should see the response payload with the above set code and reason
@Sai Saran Vaidyanathan Is that anyway to set the http status code & reason phrase using Java script ?
Check this link
@Sai Saran Vaidyanathan That works !! Thanks a Lot !