Configuring Nextcloud Full Text Search with Elasticsearch.

Installing Elasticsearch (elastic-7.x)

c.f. https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-elasticsearch-on-ubuntu-20-04

curl -fsSL https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-7.x.list
sudo apt update
sudo apt install elasticsearch

Plugin

Enable inedxing PDF, Office documents, etc.

sudo bin/elasticsearch-plugin install ingest-attachment

Enable Japanese indexing

https://qiita.com/shin_hayata/items/41c07923dbf58f13eec4

sudo bin/elasticsearch-plugin install analysis-kuromoji

Check if tokenizer is working

sudo -u www-data php ./occ fulltextsearch:check

Indexing – for the first time

sudo -u www-data php ./occ fulltextsearch:index

Indexing – automatically on the background

https://github.com/nextcloud/fulltextsearch/wiki/Basic-Installation#live-index-service

Add a service process to run background process.

# /etc/systemd/system/nextcloud-fulltext-elasticsearch-worker.service

[Unit]
Description=Elasticsearch Worker for Nextcloud Fulltext Search
After=network.target

[Service]
User=www-data
Group=www-data
WorkingDirectory=/var/www/nextcloud
ExecStart=/usr/bin/php /var/www/nextcloud/occ fulltextsearch:live -q
ExecStop=/usr/bin/php /var/www/nextcloud/occ fulltextsearch:stop
Nice=19
Restart=always

[Install]
WantedBy=multi-user.target

Enable the service

systemctl enable nextcloud-fulltext-elasticsearch-worker.service
systemctl start nextcloud-fulltext-elasticsearch-worker.service

Try the search in Japanese

References

https://github.com/nextcloud/fulltextsearch/wiki

https://qiita.com/shin_hayata/items/41c07923dbf58f13eec4