Add Gitaly data to the usage ping

Gitaly data wasn't available to the team, an this change is a first
iteration towards understanding what data we need and how to interpret
it. Later more values will be added.

For now the most important thing is the filesystem String Array, as that
includes data on ext4 exposure and NFS.

Part of: https://gitlab.com/gitlab-org/gitlab-ce/issues/60602

changelogs/unreleased/zj-gitaly-usage-data.yml

+---
+title: Add Gitaly data to the usage ping
+merge_request:
+author:
+type: added

lib/gitaly/server.rb

@@ -2,8 +2,18 @@
 module Gitaly
   class Server
-    def self.all
-      Gitlab.config.repositories.storages.keys.map { |s| Gitaly::Server.new(s) }
+    class << self
+      def all
+        Gitlab.config.repositories.storages.keys.map { |s| Gitaly::Server.new(s) }
+      end
+
+      def count
+        all.size
+      end
+
+      def filesystems
+        all.map(&:filesystem_type).compact.uniq
+      end
     end
     attr_reader :storage
@@ -36,6 +46,10 @@ module Gitaly
       storage_status&.writeable
     end
+    def filesystem_type
+      storage_status&.fs_type
+    end
+
     def address
       Gitlab::GitalyClient.address(@storage)
     rescue RuntimeError => e

lib/gitlab/usage_data.rb

@@ -136,8 +136,9 @@ module Gitlab
       def components_usage_data
         {
-          gitlab_pages: { enabled: Gitlab.config.pages.enabled, version: Gitlab::Pages::VERSION },
           git: { version: Gitlab::Git.version },
+          gitaly: { version: Gitaly::Server.all.first.server_version, servers: Gitaly::Server.count, filesystems: Gitaly::Server.filesystems },
+          gitlab_pages: { enabled: Gitlab.config.pages.enabled, version: Gitlab::Pages::VERSION },
           database: { adapter: Gitlab::Database.adapter_name, version: Gitlab::Database.version }
         }
       end

spec/lib/gitaly/server_spec.rb

@@ -47,6 +47,12 @@ describe Gitaly::Server do
     end
   end
+  describe "#filesystem_type" do
+    subject { server.filesystem_type }
+
+    it { is_expected.to be_present }
+  end
+
   describe 'request memoization' do
     context 'when requesting multiple properties', :request_store do
       it 'uses memoization for the info request' do

spec/lib/gitlab/usage_data_spec.rb

@@ -54,6 +54,7 @@ describe Gitlab::UsageData do
         gitlab_shared_runners_enabled
         gitlab_pages
         git
+        gitaly
         database
         avg_cycle_analytics
         web_ide_commits
@@ -205,6 +206,10 @@ describe Gitlab::UsageData do
       expect(subject[:git][:version]).to eq(Gitlab::Git.version)
       expect(subject[:database][:adapter]).to eq(Gitlab::Database.adapter_name)
       expect(subject[:database][:version]).to eq(Gitlab::Database.version)
+      expect(subject[:gitaly][:version]).to be_present
+      expect(subject[:gitaly][:servers]).to be >= 1
+      expect(subject[:gitaly][:filesystems]).to be_an(Array)
+      expect(subject[:gitaly][:filesystems].first).to be_a(String)
     end
   end