Bug 27252: Add deprecation warning, cross_fields pref, and add version to ES info

This patch prepares Koha to officially no longer support Elasticsearch 5.X

It adds a new system preference 'ElasticsearchCrossFields' to allow users to choose whether or not
to enable this feature

It updates the about page to add a deprecation warning if a site is running ES5

To test:
 1 - Be running Koha with Elasticsearch 5.X
 2 - Attempt to search
   Error: Unable to perform your search. Please try again.
 3 - Apply patch
 4 - Update database
 5 - Searching works
 6 - Find syspref 'ElasticsearchCrossFields'
 7 - Enable it
 8 - Searching is now broken
 9 - Check the about page
 10 - you can now see the Elasticsearch version
 11 - The systeminformation tab has a deprectaion warning
 12 - Set SearchEngine preference to 'Zebra'
 13 - View the about page - no warnings
 14 - Test again with ES6 - searching should "work" with either pref setting
 15 - There should be no warning on about pages

Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Koha/SearchEngine/Elasticsearch/QueryBuilder.pm

@@ -100,9 +100,9 @@ sub build_query {
             fields           => $fields,
             lenient          => JSON::true,
             analyze_wildcard => JSON::true,
-            type             => 'cross_fields',
         }
     };
+    $res->{query}->{query_string}->{type} = 'cross_fields' if C4::Context->preference('ElasticsearchCrossFields');
 
     if ( $options{sort} ) {
         foreach my $sort ( @{ $options{sort} } ) {

about.pl

@@ -341,6 +341,7 @@ if ( C4::Context->preference('SearchEngine') eq 'Elasticsearch' ) {
         #       fetch the list of available indexes (e.g. plugins, etc)
         $es_status->{nodes} = $es_conf->{nodes};
         my $es = Search::Elasticsearch->new({ nodes => $es_conf->{nodes} });
+        my $es_status->{version} = $es->info->{version}->{number};
 
         foreach my $index ( @indexes ) {
             my $count;

installer/data/mysql/atomicupdate/Bug_27252_add_ElasticsearchCrossFields_preference.perl

@@ -0,0 +1,9 @@
+$DBversion = 'XXX'; # will be replaced by the RM
+if( CheckVersion( $DBversion ) ) {
+    # you can use $dbh here like:
+    $dbh->do(q{
+        INSERT IGNORE INTO systempreferences ( `variable`, `value`, `options`, `explanation`, `type` ) VALUES
+       ('ElasticsearchCrossFields', '1', '', 'Enable "cross_fields" option for searches using Elastic search.', 'YesNo')
+    });
+    NewVersion( $DBversion, 27252, "Add ElasticsearchCrossFields system preference");
+}

installer/data/mysql/mandatory/sysprefs.sql

@@ -178,6 +178,7 @@ INSERT INTO systempreferences ( `variable`, `value`, `options`, `explanation`, `
 ('ElasticsearchIndexStatus_authorities', '0', 'Authorities index status', NULL, NULL),
 ('ElasticsearchIndexStatus_biblios', '0', 'Biblios index status', NULL, NULL),
 ('ElasticsearchMARCFormat', 'ISO2709', 'ISO2709|ARRAY', 'Elasticsearch MARC format. ISO2709 format is recommended as it is faster and takes less space, whereas array is searchable.', 'Choice'),
+('ElasticsearchCrossFields', '1', '', 'Enable "cross_fields" option for searches using Elastic search.', 'YesNo'),
 ('EmailAddressForSuggestions','','',' If you choose EmailAddressForSuggestions you have to enter a valid email address: ','free'),
 ('emailLibrarianWhenHoldIsPlaced','0',NULL,'If ON, emails the librarian whenever a hold is placed','YesNo'),
 ('EmailPurchaseSuggestions','0','0|EmailAddressForSuggestions|BranchEmailAddress|KohaAdminEmailAddress','Choose email address that new purchase suggestions will be sent to: ','Choice'),

koha-tmpl/intranet-tmpl/prog/en/modules/about.tt

@@ -55,6 +55,9 @@
                 <td><span class="status_warn">[% elasticsearch_fatal_config_error | html %]</span></td>
             [% ELSE %]
                 <td>
+                    Version:
+                    <span>[% elasticsearch_status.version | html %]</span>
+                    |
                     Nodes:
                     <span>[% elasticsearch_status.nodes.join(' / ') | html %]</span>
                     |
@@ -382,6 +385,12 @@
                     integration. This feature will be removed from Koha in a short term.
                     </td></tr>
                 [% END %]
+                [% IF Koha.Preference('SearchEngine') == 'Elasticsearch' && elasticsearch_status.version.substr(0,1) < 6 %]
+                    <tr><th scope="row"><strong>Deprecation warning</strong></th><td>
+                            Elasticsearch version 5.x is not supported in Koha 20.11 and greater. Please upgrade your Elasticsearch cluster
+                    </td></tr>
+                [% END %]
+
             </table>
         [% END %]
 

koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/searching.pref

@@ -86,6 +86,14 @@ Searching:
                   yes: Enable
                   no: Disable
             - "browsing search results from the bibliographic record detail page in staff interface."
+        -
+            - pref: ElasticsearchCrossFields
+              default: 0
+              choices:
+                  yes: Enable
+                  no: Disable
+            - "the cross_fields option for Elasticsearch searches, supported in Elasticsearch 6.X and above."
+            - "See documentation at https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-multi-match-query.html#type-cross-fields"
     Search form:
         -
             - pref : LoadSearchHistoryToTheFirstLoggedUser