Troubles with .gitlab-ci.yml triggers configuration - gitlab

Question

How should I set up my .gitlab-ci.yml manifest to run builds ONLY on:
Merge Request;
Push to branch with opened merge request from it (I mean when the merge request from branch Y to branch X is already opened and some new changes are pushed to branch Y);
Push to master;
I've tried to solve it with a setting like this:
job:
only:
- triggers
- /merge-requests/
- master
except:
- branches
Regarding on the documentation here: https://docs.gitlab.com/ce/ci/yaml/README.html#only-and-except-simplified
Suddenly the error occurred on my MR page:
Could not connect to the CI server. Please check your settings and try again.
When I removed only/except restrictions from my manifest, the error was gone.
What am I doing wrong here?
My Gitlab version is: GitLab Community Edition 10.8.1

Answer 1

You want to run a job only on:
merge request: I don't understand what you want here
Push to branch with opened merge request from it: you have to set a special job that call the Gitlab API to control that the current branch has a MR
A job executed only on new pushed branch:
image: alpine:latest
script:
- # <-- add here the script that call Gitlab API
only:
- branches
Push to master:
A job executed only on master:
image: alpine:latest
script:
- echo "Hello world!"
only:
- master