Update elasticsearch system check to check for new supported versions

doc/integration/elasticsearch.md

@@ -12,6 +12,7 @@ special searches:
 - [Advanced Syntax Search](../user/search/advanced_search_syntax.md)
 
 ## Version Requirements
+<!-- Please remember to update ee/lib/system_check/app/elasticsearch_check.rb if this changes -->
 
 | GitLab version | Elasticsearch version |
 | -------------- | --------------------- |

ee/changelogs/unreleased/elastic-version-check-fix.yml

+---
+title: Update elasticsearch system check to check for new supported versions
+merge_request: 8683
+author:
+type: fixed

ee/lib/system_check/app/elasticsearch_check.rb

+# frozen_string_literal: true
+
 module SystemCheck
   module App
     class ElasticsearchCheck < SystemCheck::BaseCheck
-      set_name 'Elasticsearch version 5.1 - 5.5?'
+      set_name 'Elasticsearch version 5.6 - 6.x?'
       set_skip_reason 'skipped (elasticsearch is disabled)'
       set_check_pass -> { "yes (#{self.current_version})" }
       set_check_fail -> { "no (#{self.current_version})" }
@@ -18,7 +20,14 @@ module SystemCheck
       end
 
       def check?
-        self.class.current_version.major == 5 && (1..5).cover?(self.class.current_version.minor)
+        case self.class.current_version.major
+        when 5
+          !(1..5).cover?(self.class.current_version.minor)
+        when 6
+          true
+        else
+          false
+        end
       end
 
       def show_error

ee/spec/lib/system_check/app/elasticsearch_check_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe SystemCheck::App::ElasticsearchCheck do
+  describe '#skip?' do
+    context 'with elasticsearch disabled' do
+      before do
+        allow(Gitlab::CurrentSettings.current_application_settings).to receive(:elasticsearch_indexing?).and_return(false)
+      end
+
+      it 'returns true' do
+        expect(described_class.new.skip?).to eq(true)
+      end
+    end
+
+    context 'with elasticsearch enabled' do
+      before do
+        allow(Gitlab::CurrentSettings.current_application_settings).to receive(:elasticsearch_indexing?).and_return(true)
+      end
+      it 'returns false' do
+        expect(described_class.new.skip?).to eq(false)
+      end
+    end
+  end
+
+  describe '#check?' do
+    using RSpec::Parameterized::TableSyntax
+
+    subject { described_class.new.check? }
+
+    where(:version, :result) do
+      '2.3.0' | false
+      '5.3.1' | false
+      '5.6.0' | true
+      '5.6.6' | true
+      '6.0.0' | true
+      '6.3.4' | true
+      '7.1.0' | false
+    end
+
+    with_them do
+      before do
+        # `current_version` is memoized, so we must clear it out
+        described_class.instance_variable_set(:@current_version, nil)
+        allow(Gitlab::Elastic::Client).to receive(:build).and_return(double(info: { 'version' => { 'number' => version } }))
+      end
+
+      it { is_expected.to eq(result) }
+    end
+  end
+end