[GSTG] Reprovision HAProxy with a single NIC

Production Change

Change Summary

Related to https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/15218

Change Details

  1. Services Impacted - ServiceHAProxy
  2. Change Technician - @ahmadsherif
  3. Change Reviewer - @jarv
  4. Time tracking - 1h 20 minutes
  5. Downtime Component - none

Detailed steps for the change

Pre-Change Steps - steps to be completed before execution of the change

Estimated Time to Complete (mins) - 1 minute

  • Set label changein-progress on this issue
  • Make sure no deployment to staging is tacking place (check #announcements Slack channel)

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - 60 minutes

  • Merge https://ops.gitlab.net/gitlab-com/gl-infra/config-mgmt/-/merge_requests/3573
  • Run ssh fe-01-lb-gstg.c.gitlab-staging-1.internal 'sudo /usr/local/sbin/drain_haproxy.sh -w 60'
  • Locally, in config-mgmt/environments/gstg, run tf apply -target module.fe-lb.google_compute_instance.default[0]
  • After the node has been fully provisioned, make sure it's receiving traffic by checking the logs at /var/log/haproxy.log and that its status in GCP dashboard is marked as healthy.
  • Run the following snippet for each remaining server, check the node name below after completion : 
    i=${i:-1}
i=$((i+1))
ssh fe-0$i-lb-gstg.c.gitlab-staging-1.internal 'sudo /usr/local/sbin/drain_haproxy.sh -w 60'
tf apply -target "module.fe-lb.google_compute_instance.default[$((i-1))]"
    • fe-02-lb-gstg.c.gitlab-staging-1.internal
    • fe-03-lb-gstg.c.gitlab-staging-1.internal

Post-Change Steps - steps to take to verify the change

Estimated Time to Complete (mins) - 3 minutes

  • Check /var/log/haproxy.log on the nodes for traffic logs
  • Check GCP dashboard that all nodes are marked as healthy

Rollback

Rollback steps - steps to be taken in the event of a need to rollback this change

Estimated Time to Complete (mins) - 5 minutes

Monitoring

Key metrics to observe

Summary of infrastructure changes

  • Does this change introduce new compute instances?
  • Does this change re-size any existing compute instances?
  • Does this change introduce any additional usage of tooling like Elastic Search, CDNs, Cloudflare, etc?

Summary of the above

Change Reviewer checklist

C4 C3 C2 C1:

  • The scheduled day and time of execution of the change is appropriate.
  • The change plan is technically accurate.
  • The change plan includes estimated timing values based on previous testing.
  • The change plan includes a viable rollback plan.
  • The specified metrics/monitoring dashboards provide sufficient visibility for the change.

C2 C1:

  • The complexity of the plan is appropriate for the corresponding risk of the change. (i.e. the plan contains clear details).
  • The change plan includes success measures for all steps/milestones during the execution.
  • The change adequately minimizes risk within the environment/service.
  • The performance implications of executing the change are well-understood and documented.
  • The specified metrics/monitoring dashboards provide sufficient visibility for the change. - If not, is it possible (or necessary) to make changes to observability platforms for added visibility?
  • The change has a primary and secondary SRE with knowledge of the details available during the change window.

Change Technician checklist

  • This issue has a criticality label (e.g. C1, C2, C3, C4) and a change-type label (e.g. changeunscheduled, changescheduled) based on the Change Management Criticalities.
  • This issue has the change technician as the assignee.
  • Pre-Change, Change, Post-Change, and Rollback steps and have been filled out and reviewed.
  • This Change Issue is linked to the appropriate Issue and/or Epic
  • Necessary approvals have been completed based on the Change Management Workflow.
  • Change has been tested in staging and results noted in a comment on this issue.
  • A dry-run has been conducted and results noted in a comment on this issue.
  • SRE on-call has been informed prior to change being rolled out. (In #production channel, mention @sre-oncall and this issue and await their acknowledgement.)
  • Release managers have been informed (If needed! Cases include DB change) prior to change being rolled out. (In #production channel, mention @release-managers and this issue and await their acknowledgment.)
  • There are currently no active incidents.
Edited by Ahmad Sherif