Using Policies

Add the Message Policy.

1. Navigate to Configure → APIs and choose the API Proxies tab.

   

2. Open your API view by choosing the link GWSAMPLE_BASIC_v1_date_subaccountnumber.

3. Choose the Policies button.

   

4. Choose the Edit button.

   

5. You can see the grey plus symbols on the right side.

   

6. Choose the following: Flows → TargetEndpoint → PostFlow. The plus signs are now black and usable.

   

7. Find the Assign Message Policy on the left side menu.

   Note

   To implement the policies in your API proxy, you must have a working concept on how the policies work.
   

8. Choose the plus sign at the Assign Message policy symbol. To add the following:

9. Choose the Add button in the pop-up window.

   Field Name	Value
   Policy Type	Assign Message
   Policy Name	setCredentials
   Endpoint Type	TargetEndpoint
   Flow Type	Postflow
   Stream	Incoming Request

   

10. Choose the Add button in the pop-up window.

    

11. In the XML editor, enter the following code via copy-paste:

    Note

    Be aware to substitute the Username and Password with yours.
    Code Snippet

    Copy codeSwitch to dark mode

    12345678910111213141516171819
    
    <!-- This policy can be used to create or modify the standard HTTP request and response messages -->
    <AssignMessage async="false" continueOnError="false" enabled="true" xmlns='http://www.sap.com/apimgmt'>
    <!-- Sets a new value to the existing parameter -->
      <Set>
          <Payload contentType="application/json" variablePrefix="@" variableSuffix="#">{"name":"foo",             "type":"@apiproxy.name#"}</Payload>
      </Set>
        <AssignVariable>
          <Name>request.header.username</Name>
          <Value>Your username from your GWSAMPLE_BASIC backend system</Value>
        </AssignVariable>
        <AssignVariable>
          <Name>request.header.password</Name>
          <Value>Your password from your GWSAMPLE_BASIC backend system</Value>
        </AssignVariable>
      <IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>
    <AssignTo createNew="false" type="request">request</AssignTo>
    </AssignMessage>
    

    Note

    Be sure to substitute the username and password with yours.

    Note

    You can also download the code snippets via Github for this learning journey:

    integration-suite-learning-journey/src/rev_20 at main · SAP-samples/integration-suite-learning-journey · GitHub

12. Enter your username and password in a plain text format. It is also possible to set both values encrypted from a keystore.

    

    Now, you have defined two variables, request.header.username and the request.header.password.

13. Be aware before your update and save this entry, to set a second policy that uses the variables for basic authentication.

Add the Basic Authentication Policy.

1. On the right side, choose the Basic Authentication policy and choose the plus button.

   

2. Add/check the following data:

   Field Name	Value
   Policy Type	Basic Authentication
   Policy Name	setBasicAuthentication
   Endpoint Type	TargetEndpoint
   Flow Type	Postflow
   Stream	Incoming Request

   

3. Choose the Add button within the pop-up window.

   

4. Check the entries and choose the update button (on top right of the screen).

   Switch back to the detail view of your API Proxy and choose the Save button.

5. After saving a navigation bar at the top of the API Proxy details window with a request to deploy, the API Proxy shows.

   

6. Choose the Click to Deploy link to confirm the deployment via the detail pop-up window.

   

Test your policies via resources.

1. Choose the Resources tab. Choose the first entry GET/BusinessPartnerSet, select the Try out button, and then choose the Execute button.

   
   

2. You receive an HTTP status Code with response 200 and the containing response body.

3. Check out the result.

   
   Note

   If you don't get an HTTP status Code with response 200, check your username and password in the policy. Be sure that your backend system account is not blocked by too many failed logons.

Analyze your API calls.

1. Navigate to Monitor → APIs.

   
   Note

   Your monitor can look different.

Log on to the SAP Business Accelerator Hub.

1. Open the link: https://api.sap.com

   

2. Log in through the Login button to try out the APIs.

3. Navigate to Explore → APIs.

   

Explore the policies.

1. Choose the Policy Template tab.

   

2. Now, you can check out all the available policies, which you can use in your SAP API Management.

   

3. Find the Performance_Traceability policy and open it.

   

4. Check out the documentation for more information.

5. Review the configuration of the policies, especially the proxy_request_retriving_latency.

Explore the APIs.

1. Navigate back to https://api.sap.comExplore → APIs.

2. Choose ODATA V2.

3. In the search bar, enter Purchase Order and choose Enter.

   You see a tile with the name: Purchase Order.

4. Choose the Purchase Order tile. You will find a lot of information there.

   

   Note

   The Purchase Order ODATA V2 is marked as deprecated, but don't worry it works, so try it out.

5. Choose the Try Out button.

   

6. On the left side, find Purchase Order → GET /APurchaseOrder and choose it. On top of the page, you see the chosen context, /A_PurchaseOrder.

7. Choose the Run button.

   You get an HTTP Status Code 200 and a filled Response Body and Response Header.