dansvidania / rust-camunda-client Goto Github PK

Thank you for this (auto-generated?) library, it's really useful and saved a lot of time to implement from scratch. The URI defined for the process definition API should be corrected as "process-definition". Currently it is typed as "process_definition". Please check https://docs.camunda.org/manual/latest/reference/rest/process-definition/post-start-process-instance/.

Hi @Dansvidania , here is an improvement for the library. As we discussed in Dansvidania/camunda-worker#11 Camunda REST API allows long polling. For the duration you set while you perform "fetch and lock" for an external task, you can set a timer up to 30 minutes and for that long the HTTP connection is kept alive and Camunda pushes the client newly created tasks immediately thereby eliminating the constant need for making new HTTP requests to check if there is a new task.

However, reqwest crate which is used here comes with a default time out period of 30 seconds. This breaks the long polling set longer than 30 seconds. There is a configuration function to disable it.

https://docs.rs/reqwest/0.8.4/reqwest/struct.ClientBuilder.html

fn timeout<T>(&mut self, timeout: T) -> &mut ClientBuilder 
where
    T: Into<Option<Duration>>, 
[src][−]
Set a timeout for connect, read and write operations of a Client.

Default is 30 seconds.

Pass None to disable timeout.

Hi, @Dansvidania , I see that the Decision Definition forund at https://docs.camunda.org/manual/latest/reference/rest/decision-definition/ is not generated within the library. Is there a certain reason you know?

Hi @Dansvidania , the current implementation converts Errors from the Reqwest crate into the library's own Error implementation. However, this conversion loses some part of the error messages. This is done in here: https://github.com/Dansvidania/rust-camunda-client/blob/master/src/apis/mod.rs

An example:

This is what is propogated to where the lib is used in the camunda_worker:

Reqwest(Error(Status(500), "http://localhost:8080/engine-rest/external-task/8d762d22-a7ea-11eb-a622-0242ac110002/complete"))

An this is the actual response when we make the same request from Postman:

{
    "type": "ProcessEngineException",
    "message": "ENGINE-02025 Variable 'xxxListVar' is not of the expected type 'Collection'."
}

Should we create a proper impl Fromreqwest::Error for Error implemantation or what? Any ideas?