如何在Azure API Management策略中将响应状态码修改为200

问题描述 #

我正在使用Azure API Management服务，当前的策略配置如下：

<!-- Policies are applied in the order they appear. 
     Position <base/> inside a section to inherit policies from the outer scope. 
     Comments within policies are not preserved. -->
<!-- Add policies as children to the <inbound>, <outbound>, <backend>, and <on-error> elements -->
<policies>
    <!-- Throttle, authorize, validate, cache, or transform the requests -->
    <inbound>
        <base />
        <set-backend-service base-url="https://xxx" />
    </inbound>
    <!-- Control if and how the requests are forwarded to services -->
    <backend>
        <base />
    </backend>
    <!-- Customize the responses -->
    <outbound>
        <base />
    </outbound>
    <!-- Handle exceptions and customize error responses -->
    <on-error>
        <base />
    </on-error>
</policies>

我的后端服务返回状态码201，但需要向客户端返回的响应状态码为200，请问如何修改策略以实现这一需求？

解决方案 #

在outbound策略段中添加条件判断逻辑，当检测到后端返回的状态码为201时，使用set-status策略将响应状态码修改为200后返回给客户端。修改后的完整策略配置如下：

<!--
    - Policies are applied in the order they appear.
    - Position <base/> inside a section to inherit policies from the outer scope.
    - Comments within policies are not preserved.
-->
<!-- Add policies as children to the <inbound>, <outbound>, <backend>, and <on-error> elements -->
<policies>
    <!-- Throttle, authorize, validate, cache, or transform the requests -->
    <inbound>
        <base />
    </inbound>
    <!-- Control if and how the requests are forwarded to services  -->
    <backend>
        <base />
    </backend>
    <!-- Customize the responses -->
    <outbound>
        <base />
        <choose>
            <when condition="@(context.Response.StatusCode == 201)">
                <set-status code="200" reason="OK" />
            </when>
        </choose>
    </outbound>
    <!-- Handle exceptions and customize error responses  -->
    <on-error>
        <base />
    </on-error>
</policies>

内容的提问来源于stack exchange，提问作者DeadlyMuffin