Add diagnostic message for failure during CLI search deploy (#29462)

lib/mastodon/cli/search.rb

@@ -100,6 +100,14 @@ module Mastodon::CLI
       progress.finish
 
       say("Indexed #{added} records, de-indexed #{removed}", :green, true)
+    rescue Elasticsearch::Transport::Transport::ServerError => e
+      fail_with_message <<~ERROR
+        There was an issue connecting to the search server. Make sure the
+        server is configured and running correctly, and that the environment
+        variable settings match what the server is expecting.
+
+        #{e.message}
+      ERROR
     end
 
     private

spec/lib/mastodon/cli/search_spec.rb

@@ -33,6 +33,17 @@ describe Mastodon::CLI::Search do
       end
     end
 
+    context 'when server communication raises an error' do
+      let(:options) { { reset_chewy: true } }
+
+      before { allow(Chewy::Stash::Specification).to receive(:reset!).and_raise(Elasticsearch::Transport::Transport::Errors::InternalServerError) }
+
+      it 'Exits with error message' do
+        expect { subject }
+          .to raise_error(Thor::Error, /issue connecting to the search/)
+      end
+    end
+
     context 'without options' do
       before { stub_search_indexes }