I used the latest build (not official one) in order to test the fix, and this time I'm getting HTTP CODE 200

I created a simple job with one string parameter and used the following code:

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

.
.
.
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);

MultiValueMap<String, String> form = new LinkedMultiValueMap<String, String>();
form.add("COUNT", "5");

HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<MultiValueMap<String, String>>(form,headers);

ResponseEntity<String> responce = restTemplate.exchange("http://192.168.1.126:8080/jenkins/job/test1/buildWithParameters", HttpMethod.POST, request, String.class);
.
.
.

The returned HTTP code is 200 instead of 201 (saw it on Fiddler)

Additionally, I'm getting a json result which contains the "queueItem" section, together with other non-relevant info, I can use this "queueItem" info for tracking the job, BUT when starting few instances of the same job in parallel (each instance with different parameters), in each HTTP response I'm getting the same "queueItem" as the first one I got, although, when checking the queue the other new instance were created with different item id in the queue

If this too complicated to understand, lets try to set a webex session or something similar (my mail: amos_son@malam.com)

I confirm that using the REST API, I get a 200 instead of a 201 when performing a build. The URL I call is :
https://<hidden>/jenkins/job/<JOB>/buildWithParameters?module=amoreTST

More importantly, buildWithParameters returns 201 without Location to build queue.

> the successful queueing will result in 201 status code with Location HTTP header pointing the URL of the item in the queue.

The current version of ParametersDefinitionProperty.buildWithParameters does seem to send either a 201 with redirect to a newly created or existing queue item, or a 200 with redirect to the job in case queue scheduling was refused. If you can reproduce different behavior please file a pull request with accompanying test.

Remember that you need to either POST (with a valid crumb, if Jenkins is so configured), or (for historical compatibility) GET with a token (if one is defined), in order to schedule a build: for security reasons, GET requests may not initiate actions.

Code changed in jenkins
User: Jesse Glick
Path:
src/test/java/hudson/plugins/git/RevisionParameterActionTest.java
http://jenkins-ci.org/commit/git-plugin/4fe33a1fa31459563b7d9e4c4c652b20bde6df4d
Log:
Commenting out assertions that fail in 1.521+ due to improved core behavior from JENKINS-18407.

Code changed in jenkins
User: Craig Rodrigues
Path:
src/test/groovy/com/cloudbees/plugins/flow/ConcurrencyTest.groovy
http://jenkins-ci.org/commit/build-flow-plugin/faeaa5cc2062f7c7b73073e201b12646e9538963
Log:
Delete test which no longer works in 1.521+ due to improved core behavior from JENKINS-18407

Due to the improved core behavior, in JobInvocation.groovy's run()
method, schedule2() no longer returns null when invoked from the test.

It seems that this bug is still present (version 2.138.1) - every time when a build is triggered using `POST /job/[JOB_NAME]/build` (either normally or via Curl), jenkins ALWAYS returns 302 instead of 201. This makes it impossible to trigger builds via a webhook, because the HTTP client sees that the response code is not 2xx and starts retrying it.

jnazander no you are just using the wrong endpoint (build vs. buildWithParameters). Please use the users’ list for assistance. If you believe you have encountered a bug please file a fresh report with complete steps to reproduce from scratch, linking to existing issues as appropriate.

jglick But my job doesn't have parameters, and if I try calling the job using `/buildWithParameters`, it returns HTTP 500 – `IllegalStateException: This build is not parameterized!`

In any case, Jenkins's API documentation says:

`To programmatically schedule a new build, post to this URL (https://jenkins.***.net/job/accounts/build). If the build has parameters, post to this URL and provide the parameters as form data. Either way, the successful queueing will result in 201 status code`

While in reality it returns 302. This looks like a bug to me, should I create a new ticket?

If your job has parameters, use buildWithParameters. If it does not, use build. Which is what the API documentation says. There is no bug I can see. Again please use the users’ list for assistance.