Major Any time a job is started using the `/build` or `/buildWithParameters` URL (either via the job's page itself or via an API call), it always returns a `HTTP 302` response that redirects to the job's page, instead of the correct HTTP 201.
This behavior contradicts the API documentation itself, which states:
To programmatically schedule a new build, post to this URL (/build). If the build has parameters, post to this URL (/buildWithParameters) and provide the parameters as form data. Either way, the successful queueing will result in 201 status code with Location HTTP header pointing the URL of the item in the queue.
[JENKINS-53869] Starting a job using the API returns 302 instead of 201
I can confirm this is an issue, there is no possible way to obtain the build number of a pipeline job that has been launched by calling /build or /buildWithParameters endpoint
Ardhendu Shekhar Singh
added a comment - Ardhendu Shekhar Singh
added a comment - Hi mrbq / jnazander / macjohnny ,
Is there update on this issue?
Regards,
Ardhendu Singh 
Johan Compagner
added a comment - also createItem api does this
it also gives you a redirect so if i do a post like this:
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :method: POST
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :scheme: https
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :authority: xxxx
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :path: /createItem?name=sandbox_C253ZR_NONE&mode=copy&from=salesDemo_DEV
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> content-type: application/json
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> accept: application/json
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> jenkins-crumb: XXXX
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> user-agent: Apache-HttpAsyncClient/5.1.2 (Java/17.0.4)
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> authorization: XXXX
then i don't get right away 200 back but a redirect to a pure UI page
(and i did set that i only accept application/json (or xml which also doesn't matter)
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << :status: 302
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << date: Wed, 05 Oct 2022 09:30:13 GMT
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << x-content-type-options: nosniff
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << location: https://XXXXXXX/job/sandbox_C253ZR_NONE/configure
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << content-length: 0
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << server: Jetty(10.0.11)
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << strict-transport-security: max-age=31536000
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << set-cookie: INGRESSCOOKIE=XXXXX path=/; HttpOnly; Secure
that really doesn't look ok, if i use REST and i set the right accept then it shouldn't redirect me to a UI page.
This really looks like a createJob done through the ui
Johan Compagner
added a comment - also createItem api does this
it also gives you a redirect so if i do a post like this:
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :method: POST
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :scheme: https
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :authority: xxxx
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> :path: /createItem?name=sandbox_C253ZR_NONE&mode=copy&from=salesDemo_DEV
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> content-type: application/json
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> accept: application/json
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> jenkins-crumb: XXXX
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> user-agent: Apache-HttpAsyncClient/5.1.2 (Java/17.0.4)
DEBUG org.apache.hc.client5.http.headers - c-0000000001 >> authorization: XXXX
then i don't get right away 200 back but a redirect to a pure UI page
(and i did set that i only accept application/json (or xml which also doesn't matter)
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << :status: 302
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << date: Wed, 05 Oct 2022 09:30:13 GMT
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << x-content-type-options: nosniff
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << location: https://XXXXXXX/job/sandbox_C253ZR_NONE/configure
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << content-length: 0
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << server: Jetty(10.0.11)
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << strict-transport-security: max-age=31536000
DEBUG org.apache.hc.client5.http.headers - c-0000000001 << set-cookie: INGRESSCOOKIE=XXXXX path=/; HttpOnly; Secure
that really doesn't look ok, if i use REST and i set the right accept then it shouldn't redirect me to a UI page.
This really looks like a createJob done through the ui
This seems to happen when building a "Pipeline" build. For normal builds, this does not occur.