Add "project_blob_path", "can_edit" to "all_dashboards" in metrics_dashboard.json

Objective

Add an "Edit Dashboard" link in the metrics dashboard. Part of #34779 (closed)

Requirement

Add an edit_path project_blob_path and can_edit to the dashboard data in the GET metrics_dashboard.json endpoint (e.g. /root/autodevops-deploy/environments/29/metrics_dashboard.json?...)

edit_path can_edit should only be true if the dashboard can be modified, and if they use can access this file in the reposity.

Example:

{
  "all_dashboards": [
    {
      "default": true,
      "can_edit": false,
      "display_name": "Default",
      "path": "config/prometheus/common_metrics.yml",
      "project_blob_path": null,
      "system_dashboard": true
    },
    {
      "default": false,
      "can_edit": true,
      "display_name": "anomaly_simple.yml",
      "path": ".gitlab/dashboards/anomaly_simple.yml",
      "project_blob_path": "/root/autodevops-deploy/blob/master/.gitlab/dashboards/anomaly_simple.yml",
      "system_dashboard": false
    },
    {
      "default": false,
      "can_edit": true,
      "display_name": "anomaly_subqueries.yml",
      "path": ".gitlab/dashboards/anomaly_subqueries.yml",
      "project_blob_path": "/root/autodevops-deploy/blob/master/.gitlab/dashboards/anomaly_subqueries.yml",
      "system_dashboard": false
    }
  ],
  "dashboard": {
    "dashboard": "My Dashboard",
	....
  },
  "status": "success"
}

Technical Implementation

New property could be added here:

• https://gitlab.com/gitlab-org/gitlab/blob/master/app/services/metrics/dashboard/project_dashboard_service.rb#L17
• https://gitlab.com/gitlab-org/gitlab/blob/master/app/services/metrics/dashboard/system_dashboard_service.rb#L21

Original Discussion

The following discussion from !19279 (merged) should be addressed:

• @mrincon started a discussion:

  Hardcoding /blob/master/ here is probably a bad approach, I am still search for solutions.