Route to different Web Service URL in same API?

Question

Dear all

I'm pretty new to Azure API Management and just managed to start a flow through it. However, I would also like to start other flows without creating a new API for each of them. Ideally, I would have 1 API calling different Web Service URL's based on some rules/routing/subscriptions.

Is that somehow possible and if so, could you give me a hint?

Thank you and kind regards,

Answer 1

@FabulousFab You can add multiple operations under the same API (at different paths) and leverage policies to forward requests to different web services.

At the minimum, you would need to use the set-backend-service policy for each operation. Prefer using backends instead of URLs directly.

Answer 2

I think you are looking to orchestrate request and response from different services within a single call, such that response values from previous calls can be used as input values for subsequent calls. If this is the case then you can follow below

<inbound>
<base />

    <set-backend-service base-url="http://services.eg" />
    <rewrite-uri template="/server/rest/services/0/query" />
    <set-query-parameter name="f" exists-action="append">
        <value>json</value>
    </set-query-parameter>
    <set-query-parameter name="rtrElement1" exists-action="append">
        <value>true</value>
    </set-query-parameter>
    <set-query-parameter name="where" exists-action="append">
        <value>@("some string" + context.Request.OriginalUrl.Query.GetValueOrDefault(....))</value>
    </set-query-parameter>
</inbound>
<backend>
    <base />
</backend>
<outbound>
    <base />
    <choose>
        <when condition="@( ((IResponse)context.Response).Body.As<JObject>(true)["ftr"].Count().ToString() == "0") ">
            <return-response>
                <set-status code="204" reason="No catchment area found" />
                <set-header name="Content-Type" exists-action="append">
                    <value>application/json</value>
                </set-header>
                <set-body>No data found</set-body>
            </return-response>
        </when>
        <otherwise>
            <!-- Retrieving the coordinates in the Variables “xfd” and “yfd” -->
            <set-variable name="xfd" value="@{var x = context.Response.Body?.As<JObject>(true); return x["ftr"][0]["sName"]["x"].ToString(); }" />
            <set-variable name="yfd" value="@{ var y = context.Response.Body?.As<JObject>(false); return y["ftr"][0]["sName"]["y"].ToString(); }" />
            <!-- Sending the request to the service 2 with the X and Y coordinates returned from the previous response -->
            <send-request mode="new" response-variable-name="hcNameRsp" timeout="30" ignore-error="true">
                <set-url>@($"http://s..)</set-url>
                <set-method>GET</set-method>
            </send-request>
            <!-- Retrieving the response from the send request Policy stored in variable : hcNameRsp -->
            <return-response>
                <set-status code="200" reason="OK" />
                <set-header name="Content-Type" exists-action="override">
                    <value>application/json</value>
                </set-header>
                <set-body>@{                
                        var rsp = ((IResponse)context.Variables["hcNameRsp"]).Body.As<JObject>();
                        return rsp["ftr"][0]["attributes"]["NAME"].ToString();                
                    }</set-body>
            </return-response>
        </otherwise>
    </choose>
</outbound>
<on-error>
    <base />

    <return-response>
        <set-status code="400" reason="Failed to execute query." />
        <set-header name="Content-Type" exists-action="append">
            <value>application/json</value>
        </set-header>
    </return-response>
</on-error>

Hope it helps