Using OpenSearch in GitLab 15.0 shows the error "Elasticsearch version not compatible" in the UI.

Summary

One of our customers reported that using OpenSearch 1.3.2 with GitLab 15.0 shows this error:

Elasticsearch version not compatible

I was able to replicate this using AWS OpenSearch 1.2.

Checking in the Rails console:

SystemCheck::App::SearchCheck.current_version
=> #<Gitlab::VersionInfo:0x00007fe224d0cec0 @major=1, @minor=2, @patch=4>

SystemCheck::App::SearchCheck.distribution
=> "elasticsearch"

It seems that GitLab detected this as an Elasticsearch cluster, which probably caused the error above to show.

This was also reflected in gitlab-rake gitlab:check:

Elasticsearch version 7.x-8.x or OpenSearch version 1.x ... no (elasticsearch 1.2.4)

Steps to reproduce

1. Install GitLab 15.0.
2. Setup an OpenSearch cluster (1.2 or 1.3.2)
3. Configure GitLab to use the OpenSearch cluster.

What is the current bug behavior?

UI shows Elasticsearch version not compatible.

What is the expected correct behavior?

OpenSearch integration should work.

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:         Ubuntu 20.04
Proxy:          no
Current User:   git
Using RVM:      no
Ruby Version:   2.7.5p203
Gem Version:    3.1.4
Bundler Version:2.2.33
Rake Version:   13.0.6
Redis Version:  6.2.6
Sidekiq Version:6.4.0
Go Version:     unknown

GitLab information
Version:        15.0.0-ee
Revision:       3b397c17532
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     PostgreSQL
DB Version:     13.6
URL:            https://zd-294331.jpid.xyz
HTTP Clone URL: https://zd-294331.jpid.xyz/some-group/some-project.git
SSH Clone URL:  git@zd-294331.jpid.xyz:some-group/some-project.git
Elasticsearch:  yes
Geo:            no
Using LDAP:     no
Using Omniauth: yes
Omniauth Providers:

GitLab Shell
Version:        14.3.0
Repository storage paths:
- default:      /var/opt/gitlab/git-data/repositories
GitLab Shell path:              /opt/gitlab/embedded/service/gitlab-shell

Results of GitLab application Check

Expand for output related to the GitLab application check

Checking GitLab subtasks ...
Checking GitLab Shell ...
GitLab Shell: ... GitLab Shell version >= 14.3.0 ? ... OK (14.3.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Internal API available: OK
Redis available via internal API: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Gitaly ...
Gitaly: ... default ... OK
Checking Gitaly ... Finished
Checking Sidekiq ...
Sidekiq: ... Running? ... yes
Number of Sidekiq processes (cluster/worker) ... 1/1
Checking Sidekiq ... Finished
Checking Incoming Email ...
Incoming Email: ... Reply by email is disabled in config/gitlab.yml
Checking Incoming Email ... Finished
Checking LDAP ...
LDAP: ... LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab App ...
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... skipped (no tmp uploads folder yet)
Systemd unit files or init script exist? ... skipped (omnibus-gitlab has neither init script nor systemd units)
Systemd unit files or init script up-to-date? ... skipped (omnibus-gitlab has neither init script nor systemd units)
Projects have namespace: ...
2/1 ... yes
Redis version >= 5.0.0? ... yes
Ruby version >= 2.7.2 ? ... yes (2.7.5)
Git user has default SSH configuration? ... yes
Active users: ... 1
Is authorized keys file accessible? ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... yes
Elasticsearch version 7.x-8.x or OpenSearch version 1.x ... no (elasticsearch 1.2.4)
For more information see:
doc/integration/elasticsearch.md
Checking GitLab App ... Finished
Checking GitLab subtasks ... Finished

Possible fixes