Trigger a DAG Run via the Stable REST API fails with Bad Request due to external_trigger is set

Apache Airflow version:

2.0.0

Environment:

• Cloud provider or hardware configuration: OpenStack -> VM -> Docker container
• OS (e.g. from /etc/os-release): Debian GNU/Linux 10 (buster)
• Kernel (e.g. uname -a): Linux 77f8efd77516 4.4.0-193-generic #224-Ubuntu

What happened:

I am trying to trigger a DAG run via the new stable REST-API 1.0.0 by using a Java-based client. The Java client is generated from the Airflow OpenAPI specification with OpenAPI generator version 5.0.0 .

In Airflow I have one active DAG demo

I trigger the DAG execution via the java client with the following code snippet:

ApiClient defaultClient = Configuration.getDefaultApiClient();
defaultClient.setBasePath("http://1.2.3.4:8080/api/v1);
DagRunApi dagRunApi = new DagRunApi(defaultClient);
DAGRun dagRun = new DAGRun();
try {
      DAGRun result = dagRunApi.postDagRun("demo", dagRun);

      LOGGER.debug(result);

    } catch (ApiException e) {
      e.printStackTrace();
    }

However, I receive the following exception:

BAD REQUEST

What you expected to happen:

By checking the airflow logs it turned out that the external_trigger value of the DAGRun is set but this is actually a read-only value and not allowed to be set which results in the BAD REQUEST response.

Adding the nullable: true setting to the external_trigger and recreating the java client resolved the issue!

external_trigger:
          type: boolean
          nullable: true
          readOnly: true

How to reproduce it:

Create the Java client (probably any client will produce this error) via OpenAPI generator:

1. java -jar codegen/openapi-generator-cli-5.0.0.jar generate -i openapi.yaml -g java -o .
2. create a simple java class and apply the code snippets from above

[mik-laj]

https://github.com/OpenAPITools/openapi-generator/issues/4190 It looks related.

[mik-laj]

Just out of curiosity, did you test the postDagRun call with the Airflow go client?

@houqp Can you check it?