Add duration field to stage - GraphQL

Problem to solve

The frontend needs to be able to display the total duration of a stage to implement the issue #29439

We initially discussed writing an algorithm on the client to calculate the total duration of a stage. But it would not be a long-term solution and we would be re-creating logic that already exists on the BE.

Where should the frontend get access to this data?

This data would first be displayed on the main pipeline graph. This feature is built with GraphQL, so the frontend would need to be able to access it in GraphQL. Specifically a single pipeline per project.

The query shape would look like this. And duration would potentially return null until the stage has finished running.

query getPipelineDetails($projectPath: ID!, $iid: ID!) {
  project(fullPath: $projectPath) {
    pipeline(iid: $iid) {
      ...
      stages {
        nodes {
          ...
          duration (new field)

Proposal

• add duration tracking columns to the ci_stages table:

  started_at               | timestamp without time zone |           |          |                                          | plain    |              |
  finished_at              | timestamp without time zone |           |          |                                          | plain    |              |
  duration                 | integer                     |           |          |                                          | plain    |              |

• Populate the values when the stage's state changes, like we do for pipelines: https://gitlab.com/gitlab-org/gitlab/-/blob/05393b19d5b218f263da59d7fd5a5aa3ad80cf6f/app/models/ci/pipeline.rb#L204-212
• Expose the duration value in the graphql data

added Category:Continuous Delivery GraphQL backend devopsverify grouppipeline execution typemaintenance labels

@mbobin does this issue make sense? Do I need to make any changes?

Thanks, @pburdette! I've added a plan for the implementation and a weight.

Awesome @mbobin thank you! I'll mark this one workflowready for development

cc: @jheimbuck_gl

mentioned in issue #29439

marked this issue as related to #29439

changed the description

set weight to 2

added workflowready for development label

changed milestone to %15.2

added VerifyP3 label

added sectionops label

added [deprecated] Accepting merge requests label

mentioned in issue gitlab-org/quality/triage-reports#7590 (closed)

mentioned in issue gitlab-org/quality/triage-reports#7591 (closed)

added Category:Continuous Integration label and removed Category:Continuous Delivery label

changed milestone to %Backlog

mentioned in issue #362655 (closed)

removed VerifyP3 label