CrossDesk Server

[ 中文 / English ]

Server designed for CrossDesk , supporting WSS-encrypted connections and using SQLite3 to store user information.

---

Requirements:

• xmake

Build:

git clone https://github.com/kunkundi/crossdesk-server.git

cd crossdesk-server

xmake b crossdesk_server

About Xmake

Build Options

# Switch build mode
xmake f -m debug/release

# Optional build parameters
-r : Rebuild the target
-v : Show detailed build logs
-y : Automatically confirm prompts

# Example
xmake b -vy crossdesk_server

For more information, please refer to the official Xmake documentation .

Build Docker Image

# Run from the repository root. This image contains CrossDesk Server only.
sudo docker build -f docker/dockerfile -t image-name .

Coturn now runs in a separate container. compose.yaml pins the official image coturn/coturn:4.17.0-r0-debian by digest so the tag cannot drift.

Coturn 4.17.0 enables stateless nonces by default. Compose also keeps the nonce secret stable and passes --dtls explicitly because DTLS became opt-in in this release.

Run Services

Use Published Images (Recommended for Servers)

Download compose.yaml and env.example from the GitHub Release. The released env.example pins CROSSDESK_IMAGE to that release tag:

cp env.example .env

# Set the public/private IPs, ports, and TURN credentials.
vi .env

sudo docker compose pull
sudo docker compose up -d
sudo docker compose ps

When using .env.example from the repository, change CROSSDESK_IMAGE from latest to the exact release tag intended for production.

Build from Local Source

Build the binary as described above, place it at dist/crossdesk_server, and then run:

cp .env.example .env
vi .env
sudo docker compose up -d --build

Compose starts two independent containers:

• crossdesk_server runs CrossDesk Server and generates the shared certificates on first startup.
• crossdesk_coturn runs the pinned official Coturn image after the certificates are ready, and can be upgraded, restarted, and resource-limited independently.

Parameters

• EXTERNAL_IP: The server’s public IP. This corresponds to Server Address in the CrossDesk client’s Self-Hosted Server Configuration.
• INTERNAL_IP: The server’s internal IP.
• CROSSDESK_SERVER_PORT: The port used by the self-hosted service. This corresponds to Server Port in the CrossDesk client’s Self-Hosted Server Configuration.
• COTURN_PORT: The port used by the COTURN service. This corresponds to Relay Service Port in the CrossDesk client’s Self-Hosted Server Configuration.
• MIN_PORT / MAX_PORT: The port range used by the COTURN service. Example: MIN_PORT=50000, MAX_PORT=60000. Adjust the range depending on the number of clients.
• COTURN_USERNAME / COTURN_PASSWORD: TURN long-term credentials; they must match the client configuration.
• COTURN_STATELESS_NONCE_SECRET: Generate it with openssl rand -hex 32 and keep it stable so Coturn restarts do not force every client through an extra 438 re-authentication round trip.
• COTURN_LOG_LEVEL: Defaults to warning to avoid per-request debug logging.
• COTURN_MEMORY_LIMIT: Coturn container memory limit; defaults to 512m and can be adjusted for expected concurrency.
• CROSSDESK_DATA_DIR / CROSSDESK_LOG_DIR: Host directories for persistent data, certificates, and CrossDesk logs.

Logging Mode (Default: Hybrid)

Compose uses a hybrid logging model by default:

• CrossDesk business logs continue to be written under /var/log/crossdesk/ and are persisted to the host through CROSSDESK_LOG_DIR for backup, download, and application troubleshooting.
• Coturn runtime logs go only to stdout. Docker rotates them with max-size=50m and max-file=3, retaining approximately 150 MB at most so abnormal public traffic cannot grow the log indefinitely.
• Coturn no longer creates /var/log/crossdesk/turn.log, avoiding duplicate copies in both a log file and Docker's container log.

When migrating from the previous docker run deployment and retaining /root/workspace/server_config, set the following in .env:

CROSSDESK_DATA_DIR=/root/workspace/server_config
CROSSDESK_LOG_DIR=/root/workspace/server_config/logs

This reuses the existing certs, db, and CrossDesk log directories. Coturn's high-volume runtime log remains bounded and rotated by Docker instead of being written there.

View or export Coturn logs with:

# Follow the most recent 200 lines.
sudo docker logs -f --tail 200 crossdesk_coturn

# Show the last hour.
sudo docker logs --since 1h crossdesk_coturn

# Export an incident to the persistent log directory when needed.
sudo docker logs --since 1h crossdesk_coturn \
  > /root/workspace/server_config/logs/coturn-export.log 2>&1

Docker removes the Coturn container log when the container is deleted. Export incident logs before removal when long-term retention is required, or forward them to a centralized logging system.

Notes

• The server must open the following ports: COTURN_PORT/udp, COTURN_PORT/tcp, MIN_PORT–MAX_PORT/udp, and CROSSDESK_SERVER_PORT/tcp.
• Coturn uses EXTERNAL_IP/INTERNAL_IP mapping for cloud servers behind public NAT.
• Docker stdout/stderr logs for both containers are limited to three 50 MB files.
• Certificate files will be automatically generated on first startup and persisted to the host at /var/lib/crossdesk/certs.
• The database file will be automatically created and stored at /var/lib/crossdesk/db/crossdesk-server.db.
• CrossDesk business logs are persisted under /var/log/crossdesk/; view rotating Coturn logs with docker logs crossdesk_coturn.

Permission Notice If the directories automatically created by Docker belong to root and have insufficient write permissions, the container user may not be able to write to them. This can cause:

• Certificate generation failure, leading to startup script errors and container exit.
• Database directory creation failure, causing the program to throw exceptions and crash.
• Log directory creation failure, preventing logs from being written (though the program may continue running).

Solution: Manually set permissions before starting the container:

sudo mkdir -p /var/lib/crossdesk /var/log/crossdesk
sudo chown -R $(id -u):$(id -g) /var/lib/crossdesk /var/log/crossdesk

Service Stats Endpoint

After the service starts, you can query runtime stats through the same HTTPS port:

Official CA deployment example:

curl https://your-domain.example.com:9090/stats

Self-signed certificate deployment example:

curl --cacert /var/lib/crossdesk/certs/api.crossdesk.cn_root.crt \
  https://your-server-ip:9090/stats

Notes:

• Official CA certificates are usually trusted by the operating system, so curl does not need an extra --cacert
• Self-signed certificates require the root certificate api.crossdesk.cn_root.crt to be provided explicitly
• The request host must match the domain name or IP address in the server certificate; do not replace it with 127.0.0.1 arbitrarily

The /api/stats path is also supported. Example response:

{
  "online_device_count": 12,
  "online_web_client_count": 2,
  "active_connection_count": 3,
  "online_duration_seconds": 86400,
  "total_online_seconds": 259200,
  "total_control_seconds": 3600,
  "total_controlled_seconds": 7200
}

• online_device_count: Number of online devices, excluding temporary web-* clients and C-* clone clients
• online_web_client_count: Number of online web clients, counting only temporary web-* clients
• active_connection_count: Number of active in-progress connections, summed from the current guests connected to each host; a guest's own login or join connection is not counted separately
• online_duration_seconds: Sum of the current online session duration for online devices, excluding temporary web-* clients and C-* clone clients
• total_online_seconds: Sum of accumulated device online duration, including the current session duration for devices that are still online
• total_control_seconds: Sum of accumulated duration where devices are controlling another device, including active remote-control sessions
• total_controlled_seconds: Sum of accumulated duration where devices are being controlled, including active remote-control sessions
• The response includes Access-Control-Allow-Origin: *, so it can be called directly from browser fetch

Certificate Files

If you use the built-in self-signed certificate flow, you can find the root certificate api.crossdesk.cn_root.crt at /var/lib/crossdesk/certs on the host machine. Download it to your client device and select it in the Certificate File Path field under the CrossDesk client’s Self-Hosted Server Settings.

If you deploy an official CA certificate, you usually do not need to distribute this root certificate separately, because clients and curl will validate the certificate with the system trust store.

Admin Dashboard

The server can serve an embedded admin dashboard at /admin on the same HTTPS port.

Enable it by setting both environment variables before startup:

ADMIN_USERNAME=admin
ADMIN_PASSWORD=change-this-password

Compose example: set the following values in .env:

ADMIN_USERNAME=admin
ADMIN_PASSWORD=change-this-password

Then apply the configuration:

sudo docker compose up -d

After startup, open:

https://your-domain.example.com:9090/admin

The dashboard shows online devices, online web clients, active remote-control sessions, accumulated online duration, accumulated control duration, and accumulated controlled duration, and supports disconnecting a selected remote-control session. It includes a China user-distribution map where darker provinces have more users, with users outside China summarized separately. The client-presence table defaults to online PC clients and provides online, active remote-control, offline, and all status filters plus a PC/Web client-kind selector; it also supports search, pagination, sorting, expandable details, and the geographic location resolved from the current online connection IP. Client IP and geolocation are kept only as in-memory online state, not persisted as device profile data in the database. The current online duration refreshes live while a client is online, and the row stays visible with the last-online timestamp after the client goes offline.

Public IP geolocation does not call an external service by default. Private, loopback, and Docker private-network addresses are shown as Private network. Set CROSSDESK_GEOIP_LOOKUP=1 and provide an IP2Location API key with CROSSDESK_GEOIP_KEY to enable public GeoIP lookups. The default request is https://api.ip2location.io/?key={key}&ip={ip}. The resolver reads only country_name, country_code, and region_name, and builds location text such as California, United States of America; city fields are no longer read or displayed. Geo distribution counts a client as unknown only when both country and a recognizable province are missing. If you use the IP2Location.io Free plan or keyless API, attribution is required; the admin geo-distribution area displays CrossDesk uses IP2Location.io IP geolocation web service. with a link to https://www.ip2location.io. Configure the endpoint with CROSSDESK_GEOIP_SCHEME, CROSSDESK_GEOIP_HOST, CROSSDESK_GEOIP_PORT, and CROSSDESK_GEOIP_PATH; {ip} and {key} in the path are replaced before the request. The lookup timeout can be adjusted with CROSSDESK_GEOIP_TIMEOUT_MS; the default is 1200ms. Successful IP results are cached; failed results are not stored as device locations. A background IP queue deduplicates lookups by IP and re-enqueues failures with backoff. If no online device is using an IP when a retry runs, the job is dropped. Backoff starts at 60000ms and doubles up to 1800000ms by default. Tune this with CROSSDESK_GEOIP_FAILURE_TTL_MS and CROSSDESK_GEOIP_FAILURE_MAX_TTL_MS.

The admin frontend assets live in src/admin/web and are copied to /crossdesk-server/admin in the container. Set CROSSDESK_ADMIN_WEB_DIR to serve a custom frontend directory. The China map boundary asset china-provinces.json is generated from the ISC-licensed china-map-geojson@1.0.4 province-level GeoJSON data.