ONLYOFFICE

Ascensio System SIA's document server. WOPI host with a browser editor.

This page is about ONLYOFFICE only. Nothing here is evidence about Euro-Office, Collabora or LibreOffice, even where the products are related.

Deployment shape

Document server	sidecar container filinq-onlyoffice, image onlyoffice/documentserver:latest (3.32 GB), host port 8092
Nextcloud connector	app id onlyoffice, inside the nextcloud container at /var/www/html/custom_apps/onlyoffice — not bind-mounted, see README

1. Start the server

docker compose -f docker-compose.office.yml --profile onlyoffice up -d
docker inspect filinq-onlyoffice --format '{{.State.Health.Status}}'   # want: healthy

First boot takes 1–3 minutes. The port answers well before the converters are ready, so the healthcheck greps for the literal true from /healthcheck rather than accepting a 200.

2. WOPI is OFF by default — measured on this image

default.json in /etc/onlyoffice/documentserver/ ships:

"wopi": { "enable": false }

With it unset, measured 2026-08-16:

Signal	Result
container health	healthy
GET /healthcheck	200, body true
GET /	302
GET /hosting/discovery	404

Container up, port answering, admin page green — and no WOPI at all. The overlay sets WOPI_ENABLED=true, which flips discovery to 200.

3. Install the connector

Not on the Nextcloud appstore for NC 34 (occ app:install onlyoffice fails with "not found on the appstore"). From the upstream release:

curl -sL -o onlyoffice.tar.gz \
  https://github.com/ONLYOFFICE/onlyoffice-nextcloud/releases/download/v10.1.2/onlyoffice.tar.gz
tar -xzf onlyoffice.tar.gz
docker cp onlyoffice nextcloud:/var/www/html/custom_apps/
docker exec nextcloud chown -R www-data:www-data /var/www/html/custom_apps/onlyoffice
docker exec nextcloud php occ app:enable onlyoffice

4. Three URLs, three directions

# BROWSER -> server. Must be reachable from the HOST. Not a container name.
docker exec nextcloud php occ config:app:set onlyoffice DocumentServerUrl \
    --value="http://localhost:8092/"

# NEXTCLOUD -> server. Resolved inside the container, so it IS the container name.
docker exec nextcloud php occ config:app:set onlyoffice DocumentServerInternalUrl \
    --value="http://filinq-onlyoffice/"

# SERVER -> NEXTCLOUD, to fetch and save the file.
docker exec nextcloud php occ config:app:set onlyoffice StorageUrl \
    --value="http://nextcloud/"

Setting only the first to the container name renders the editor and immediately shows "ONLYOFFICE cannot be reached" — the browser cannot resolve filinq-onlyoffice. Everything else is correct; only the direction is wrong.

5. Verified 2026-08-16

container running                          PASS  running
container health                           PASS  healthy
reachable from nextcloud                   PASS  HTTP 302
WOPI discovery                             PASS  200 at /hosting/discovery
conversion (docx->odt)                     PASS  ok at /ConvertService.ashx (json/url)
self-report (/healthcheck)                 ----  true

Additionally, end to end through the UI:

• opened subsidiebesluit.docx in the ONLYOFFICE editor at /apps/onlyoffice/<fileId>
• the Hermiq chat changed "binnen zes weken" → "binnen vier weken"
• verified on the bytes, and by having ONLYOFFICE convert the edited file to text
• anchor round-trip docx → odt → docx rewrote word/document.xml (1599 → 2590 B) and all five content-hash anchors survived, ordinal included
• a document with an embedded chart rendered to a 51,777 B PDF against 25,793 B without it

Conversion API

JSON body naming a URL the server fetches itself:

POST /ConvertService.ashx
{"async":false,"filetype":"docx","key":"...","outputtype":"odt","url":"http://..."}

⚠️ docx → docx is a passthrough on this server: it returns a package whose parts are byte-identical, only the ZIP container differs. Use a format change when measuring whether the engine actually re-serialises.