Stop returning alerts from prometheus alerts endpoint

What does this MR do and why?

Implements #372115 (closed)

Do not return any JSON response from the Prometheus alerts endpoint.

When Prometheus sends an alert it does not expect any returning values. We can safely drop the JSON response.

How to verify locally

Prometheus

1. Setup [Prometheus Integration]https://docs.gitlab.com/ee/operations/incident_management/integrations.html#http-endpoints) via Settings > Monitor > Alerts
2. Clone https://gitlab.com/splattael/gitlab-manual-prometheus
3. Edit gitlab-manual-prometheus/alertmanager.yml:

global: {}
receivers:
- name: gitlab
  webhook_configs:
  - send_resolved: true
    # e.g. url: http://192.168.10.38:3001/manual-prometheus/autodevops-deploy/prometheus/alerts/notify.json
    url: http://localhost:3000/gitlab-org/gitlab-test/prometheus/alerts/notify.json
    http_config:
      # e.g. bearer_token: 2195dc9c136400428d0124805e78a7bb
      bearer_token: c34fc9a8840666ba815429a2af6dab94
route:
  group_interval: 5s
  group_wait: 5s
  receiver: gitlab
  repeat_interval: 5m

4. gdk stop prometheus (if running) to allow our prometheus to be bind on port 9090
5. docker-compose up and wait ~10 seconds
6. See http://localhost:3000/gitlab-org/gitlab-test/-/alert_management/2/details
7. Via curl

$ curl -v --request POST --data '{"version":"4","receiver":"gitlab","status":"firing","alerts":[{"status":"firing","labels":{"alertname":"title","gitlab":"hook","gitlab_alert_id":""},"annotations":{},"startsAt":"2018-09-24T08:57:31.095725221Z","endsAt":"0001-01-01T00:00:00Z","generatorURL":"http://prometheus-prometheus-server-URL"}],"groupLabels":{"alertname":"title"},"commonLabels":{"alertname":"title","gitlab":"hook","gitlab_alert_id":null},"commonAnnotations":{},"externalURL":"","groupKey":"{}:{alertname='title'}"}
' --header "Authorization: Bearer TOKEN" --header "Content-Type: application/json"  http
://localhost:3000/gitlab-org/gitlab-test/prometheus/alerts/notify.json

# => 201 Created

HTTP Endpoint

This endpoints still returns information for created alerts

1. Setup HTTP Endpoint via Settings > Monitor > Alerts
2. Fire an alert via curl

$ curl -v --request POST --data '{ "title": "Testing" }' --header "Authorization: Bearer TOKEN" --header "Content-Type: application/json"  http://localhost:3000/gitlab-org/gitlab-test/alerts/notify/test/ID.json

3. Request succeeds and returns [{"iid":1,"title":"Testing"}]
4. http://localhost:3000/gitlab-org/gitlab-test/-/alert_management/1/details is available

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

changed milestone to %15.6

added Category:Incident Management [deprecated] Accepting merge requests backend bugperformance devopsmonitor grouprespond priority3 sectionops severity3 typebug workflowready for development labels

assigned to @ck3g

Reviewer roulette

Changes that require review have been detected!

Please refer to the table below for assigning reviewers and maintainers suggested by Danger in the specified category:

Category	Reviewer	Maintainer
backend	Drew Blessing (@dblessing) (UTC-5, 7 hours behind @ck3g)	Vasilii Iakliushin (@vyaklushin) (UTC+2, same timezone as @ck3g)

To spread load more evenly across eligible reviewers, Danger has picked a candidate for each review slot, based on their timezone. Feel free to override these selections if you think someone else would be better-suited or use the GitLab Review Workload Dashboard to find other available reviewers.

To read more on how to use the reviewer roulette, please take a look at the Engineering workflow and code review guidelines. Please consider assigning a reviewer or maintainer who is a domain expert in the area of the merge request.

Once you've decided who will review this merge request, assign them as a reviewer! Danger does not automatically notify them for you.

If needed, you can retry the danger-review job that generated this comment.

Generated by Danger

removed [deprecated] Accepting merge requests label

added 1 commit

• 845232a7 - Stop returning alerts from prometheus alerts endpoint

Compare with previous version

Allure report

allure-report-publisher generated test report!

e2e-review-qa: test report for 53b9c7c6

expand test summary

+------------------------------------------------------------+
|                       suites summary                       |
+-------+--------+--------+---------+-------+-------+--------+
|       | passed | failed | skipped | flaky | total | result |
+-------+--------+--------+---------+-------+-------+--------+
+-------+--------+--------+---------+-------+-------+--------+
| Total | 0      | 0      | 0       | 0     | 0     | ➖     |
+-------+--------+--------+---------+-------+-------+--------+

marked this merge request as ready

marked the checklist item I have evaluated the MR acceptance checklist for this MR. as completed

@sgarg_gitlab could you please review this one? Thanks

requested review from @sgarg_gitlab

Hi, Everything looks great to me Just some minor comments please check

removed review request for @sgarg_gitlab

requested review from @sgarg_gitlab

approved this merge request

@sgarg_gitlab, thanks for approving this merge request.

This is the first time the merge request is approved. To ensure full test coverage, a new pipeline will be started shortly.

For more info, please refer to the following links:

• rspec minimal jobs
• jest minimal jobs
• merging a merge request.

added 1 deleted label

added 652 commits

• 845232a7...89a3da03 - 651 commits from branch master
• 1f9cdf20 - Stop returning alerts from prometheus alerts endpoint

Compare with previous version

requested review from @splattael

removed review request for @sgarg_gitlab

changed the description

changed the description

changed the description

approved this merge request

resolved all threads

enabled an automatic merge when the pipeline for 8d7fa6de succeeds

aborted the automatic merge because source branch was updated

added 844 commits

• 1f9cdf20...e5c9b7f4 - 843 commits from branch master
• 53b9c7c6 - Stop returning alerts from prometheus alerts endpoint

Compare with previous version

enabled an automatic merge when the pipeline for cbad5b7b succeeds

merged

mentioned in commit 8d88677b

added workflowstaging-canary label and removed workflowready for development label

added workflowcanary label and removed workflowstaging-canary label

added workflowstaging label and removed workflowcanary label

added workflowproduction label and removed workflowstaging label

added releasedcandidate label

mentioned in issue #372115 (closed)

mentioned in merge request kubitus-project/kubitus-installer!1646 (merged)

added releasedpublished label and removed releasedcandidate label