2022-11-16: [GPRD] Upgrade Consul cluster to 1.13.3 (2/5)

Production Change

Change Summary

We're currently running a Consul server cluster on physical VMs using a very old unsupported version of Consul (1.7.2). This CR is just one of several with the end goal being to deploy a Consul server cluster in k8s using the latest version of Consul (using the official and latest consul-k8s chart), decommission the Consul server cluster running on VMs and upgrade/migrate all Consul clients running in k8s and VMs.

We have carried out this process in staging (see CR). It was largely successful with a few lessons learnt along the way that will hopefully make the production deploy even smoother.

This CR aims to upgrade the Consul cluster deployed in #8032 (closed) to the latest version (1.13.3).

Issue: https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/16268
Epic: &844 (closed)

Change Details

  1. Services Impacted - ServiceConsul
  2. Change Technician - @gsgl
  3. Change Reviewer - @f_santos
  4. Time tracking - 2.5hrs
  5. Downtime Component - none

Detailed steps for the change

Change Steps - steps to take to execute the change

Estimated Time to Complete (mins) - 150min

  • Set label changein-progress /label ~change::in-progress
  • On one of the Consul members (eg. console), get Consul member list and peer list and save to a file:
    • consul members | tail -n+2 | sort -k 1 > consul-members.list
    • consul operator raft list-peers | tail -n+2 | sort -k 1 > consul-peers.list
  • On each Consul server VM:
    • Disable Chef
    • Shutdown Consul (consul leave)
    • On another Consul host, ensure it is listed as left in consul members
    • On another Consul host: consul force-leave -prune <consul host that was shutdown>
    • Disable Consul to ensure it doesn't start up again: sudo systemctl disable consul
  • Verify Consul Member List matches the one previously gathered minus the Consul Server VMs.
  • Take a snapshot: consul snapshot save pre-consul-upgrade-1-8-19.snap
  • Bump k8s Consul server version to 1.8.19 (see doco)
  • Take a snapshot: consul snapshot save pre-consul-upgrade-1-10-12.snap
  • Bump k8s Consul server version to 1.10.12
  • Take a snapshot: consul snapshot save pre-consul-upgrade-1-12-6.snap
  • Bump k8s Consul server version to 1.12.6
  • Take a snapshot: consul snapshot save pre-consul-upgrade-1-13-3.snap
  • Bump k8s Consul server version to 1.13.3
  • Enable Consul UI
  • Set label changecomplete /label ~change::complete

Rollback

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

Estimated Time to Complete (mins) - Estimated Time to Complete in Minutes

  • Revert to the desired version
  • Restore desired Consul snapshot (see doco)
  • Set label changeaborted /label ~change::aborted

Monitoring

Key metrics to observe

Change Reviewer checklist

C4 C3 C2 C1:

  • Check if the following applies:
    • 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:

  • Check if the following applies:
    • 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.
    • The labels blocks deployments and/or blocks feature-flags are applied as necessary

Change Technician checklist

  • Check if all items below are complete:
    • The change plan is technically accurate.
    • This Change Issue is linked to the appropriate Issue and/or Epic
    • 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.
    • The change execution window respects the Production Change Lock periods.
    • For C1 and C2 change issues, the change event is added to the GitLab Production calendar.
    • For C1 and C2 change issues, the 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.)
    • For C1 and C2 change issues, the SRE on-call provided approval with the eoc_approved label on the issue.
    • For C1 and C2 change issues, the Infrastructure Manager provided approval with the manager_approved label on the issue.
    • 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 that are severity1 or severity2
    • If the change involves doing maintenance on a database host, an appropriate silence targeting the host(s) should be added for the duration of the change.
Edited by Gonzalo Servat