Getting io.camunda.connector.api.error.ConnectorException while trying REST Connector for Keycloak token API

Camunda 8 Topics Discussion & Questions
1

Getting this error, while trying to execute REST Connector
The endpoint that I am trying to access is working in postman and sending a response.

https://keycloak.localhost.com/realms/my-realm/protocol/openid-connect/token

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2

Hi @Sunil_Purohit, welcome to the forum! Are you using SaaS or Self-Managed? I believe that particular error occurs when the connector can’t make a connection to the URL provided. Could you also provide a screenshot of the connector configuration in Modeler?

3

I am using Self Managed - Docker Deplyment. @nathan.loding

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4

Screenshot with URL and Header

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5

@Sunil_Purohit - everything looks good in the screenshots. I would be curious if you can make a curl request to the URL from inside the connectors container. What is the output of a command like:

docker exec connectors curl http://keycloak......./token

(Replace “connectors” with the container name, and insert the proper URL of course!)

6

I would like to add few more points.

  1. What protocol are you using in postman, http or https
  2. From your initial post, you are trying to access the keycloak using “HTTPS”, did you setup https for keycloak in the docker compose setup. By default only HTTP is enabled.
  3. Second screenshot you mentioned HTTP end point in the connector configuration.
  4. Please do check the https request using POSTMAN.
  5. What is the Camunda version are you using?
  6. Are you running default Keycloak comes with Docker-compose or externally hosting keycloak.
7

Yes here it is working,

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8

I tried with both http and https… but none working in the Camunda and https is working in POSTMAN.

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9

Getting this error…

{“code”:“401”,“variables”:{“response”:{“headers”:{“X-Frame-Options”:“SAMEORIGIN”,“Referrer-Policy”:“no-referrer”,“Strict-Transport-Security”:“max-age=31536000; includeSubDomains”,“Cache-Control”:“no-store”,“X-Content-Type-Options”:“nosniff”,“Connection”:“keep-alive”,“Pragma”:“no-cache”,“X-XSS-Protection”:“1; mode=block”,“Content-Length”:“93”,“Date”:“Fri, 23 May 2025 11:24:32 GMT”,“Content-Type”:“application/json”},“body”:{“error”:“invalid_client”,“error_description”:“Invalid client or Invalid client credentials”}}},“message”:“Unauthorized”,“type”:“io.camunda.connector.api.error.ConnectorException”}

10

@Sunil_Purohit - this is definitely a strange issue. I did some further research:

Are you using Camunda’s docker-compose configuration? Can you share your docker-compose file (and any related files, such as .env, with secrets redacted where necessary)?

I also noticed in the docker exec command you used https for the URL, but in your screenshot of Modeler, it is using http. Do you get the same error if you use the exact same URL from the docker exec command, or do you get a different error? If you use the http URL in the docker exec command, does it still work, or does it fail? If it fails, what is the error?

11

This time i got this error:
{“code”:“401”,“variables”:{“response”:{“headers”:{“X-Frame-Options”:“SAMEORIGIN”,“Referrer-Policy”:“no-referrer”,“Strict-Transport-Security”:“max-age=31536000; includeSubDomains”,“Cache-Control”:“no-store”,“X-Content-Type-Options”:“nosniff”,“Connection”:“keep-alive”,“Pragma”:“no-cache”,“X-XSS-Protection”:“1; mode=block”,“Content-Length”:“93”,“Date”:“Fri, 23 May 2025 11:43:33 GMT”,“Content-Type”:“application/json”},“body”:{“error”:“invalid_client”,“error_description”:“Invalid client or Invalid client credentials”}}},“message”:“Unauthorized”,“type”:“io.camunda.connector.api.error.ConnectorException”}

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12

If you could share the details about your setup/config details, we can tryout in our local environment and keep you updated.

Please do share the details what @nathan.loding requested.

I also asked the same details, but you are answering the issue only, to replicate we need more details.

13

@Sunil_Purohit - the error you are seeing is an error from the API you are calling, not from the connector itself. The REST connector forwards the error the HTTP client received back to your process. It looks like you have something misconfigured for those credentials within Keycloak, perhaps.

14

I don’t know if this is going to work, but try changing your payload from

=
{
   "client_id":"redacted_value";
   "client_secret":"redacted_value";
   "password":"redacted_value";
   "username":"user'sID";
   "grant_type":"password"
}

to something more like:

"client_id=redacted_value
client_secret=redacted_value
password=redacted_value
username=user'sID
grant_type=password"