[FLINK-37430] Operator hides the actual error on deployment issues

[rodmeneses]

What is the purpose of the change

The operator often hides the actual issue for deployment errors and do not correctly report the error events.

Brief change log

We are reporting the first 3 possible exceptions in the exception hierarchy in the error events.

Verifying this change

This change added tests and can be verified as follows:

• Added new unit tests

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changes to the CustomResourceDescriptors: no
• Core observer or reconciler logic that is regularly executed: no

Documentation

• Does this pull request introduce a new feature? no

[gyfora]

So many test cases feel a bit over the top, could we narrow it down to 2-3 cases that cover the functionality?

[gyfora]

You could add a test for the non serializable case such as:

    @Test
    void testSerializedThrowableError() {
        var serializedException = new SerializedThrowable(new NonSerializableException());
        assertThat(ExceptionUtils.getExceptionMessage(serializedException))
                .isEqualTo("Unknown Error (SerializedThrowable)");
    }

    private static class NonSerializableException extends Exception {
        private void writeObject(java.io.ObjectOutputStream stream) throws IOException {
            throw new IOException();
        }
    }

[rodmeneses]

good idea!

[gyfora]

The e2es for Flink 2.0 started to fail after the official release, so we have new docker images. Merging this to fix the maven build then going to work on fixing the 2.0 compatibility.