Access external sources from Kyma function

[lucasmillbrodt]

Dear all,

I am experimenting in the Kyma environment and I would like to access an external OData-service (in this case one that is anchored in our C4C) in a Node.js-function. I can see and use the credentials saved in the environment variables, however, I am uncertain which JavaScript-function can be used in this environment to access the external source.

So far, my function looks like this. Upon contacting the API-Endpoint directing to this function, I receive my username of the C4C (as saved in the environment variables) and the unique entity-id as served by the C4C after firing the Event Notification.

module.exports = { 
  main: function (event, context) {
    // access to environment variables
    var oCredentials = JSON.parse(process.env.CONFIGURATION);
    var sUser = oCredentials.credentials.username;
    
    // make the incoming JSON readable by Node.js and select the Unique-ID (Entity-ID)
    var sEventData = event.data.replace(/-/g, '');
    var oEventNotification = JSON.parse(sEventData);
    var sEntityId = oEventNotification.data.entityid;
    return sUser + " " + sEntityId;
  }
}

If I simulate this code by sending a payload via Postman, I see, that I get the values I selected. My next step would be fetching the corresponding data with this entity-id from the OData Service. Is this possible in this manner?

Also, as you can see, my C4C is already recognized by the Kyma-environment:

All the best

Lucas Millbrodt

[lucasmillbrodt]

Thank you all! With the workaround of jamie.cawley I can read all the data. My final step would be to POST the data I have fetched from one Custom OData-Service to another Custom OData-Service. For this I first fetch the CSRF-token, then I use a function to POST to the C4C-Custom OData-Service. For this I use this code-fragment, however, even though the Token is transmitted (also visible in the C4C-OData API Monitor), I get an error message telling me that validation of the token failed. Is there anything I am missing?

await axios({
    auth: {
     username: oCredentials.credentials.username,
 password: oCredentials.credentials.password
 },
 headers: {
 "x-csrf-token" : sToken, // The token previously fetched via GET
 "Content-Type" : "application/json"
 },
 method: 'post',
 url: sWriteURL + "Z_EventRootCollection('" + sEntityId + "')",
 data: {
 StartDate : oResults.StartDate,
 StartTime : oResults.StartTime,
 EndTime : oResults.EndTime,
 Description : oResults.Description,
 Source : oResults.Source
 }
});

Best regards

Lucas

[jamie_cawley]

Hi Lucas,

When you are sending the post most sure you include the cookies received in the response for obtaining the x-csrf-token.

Regards,

Jamie

[lucasmillbrodt]

Hey Jamie,

do you have a suggestion on how to implement the inclusion of cookies via the Node.js-Code?

Best regards

Lucas

[jamie_cawley]

The values should be in the set-cookie headers, just copy and send them the same way you are doing with the x-csrf-token.

Regards,

Jamie

[lucasmillbrodt]

Hi Jamie,

I set the cookies acoordingly, as to be seen in this screenshot:

Sadly, the error message remains the same (It says CSRF token validation failed):

Best regards

Lucas

[jamie_cawley]

Try setting the headers with

headers: {
"x-csrf-token": resp.headers['x-csrf-token'],
        "Cookie": resp.headers["set-cookie"].join(";")
      },

[lucasmillbrodt]

Thank you Jamie,

this solved my problems.

All the best

Lucas