Client Push

Update notifications for nextcloud clients

About

This app attempts to solve the issue where Nextcloud clients have to periodically check the server if any files have been changed. In order to keep sync snappy, clients wants to check for updates often, which increases the load on the server.

With many clients all checking for updates a large portion of the server load can consist of just these update checks.

By providing a way for the server to send update notifications to the clients, the need for the clients to make these checks can be greatly reduced.

Update notifications are provided on a "best effort" basis, updates might happen without a notification being sent and a notification can be sent even if no update has actually happened. Clients are advised to still perform periodic checks for updates on their own, although these can be run on a much lower frequency.

Requirements

This app requires a redis server to be setup and for nextcloud to be configured to use the redis server.

Quick setup

The app comes with a setup wizard that should guide you through the setup process for most setups.

• Install the "Client Push" (notify_push) app from the appstore
• Run occ notify_push:setup and follow the provided instructions, If the setup wizard fails you can find manual instructions below.

Manual setup

The setup required consists of three steps

• Install the notify_push app from the appstore
• Setting up the push server
• Configuring the reverse proxy
• Configuring the nextcloud app

For Nextcloud Snap users:
The snap team made a wiki page how to install Client Push in Nextcloud snap. See their Wiki page!

Push server

The push server should be setup to run as a background daemon, the recommended way is by setting it up as a system service in the init system. If you're not using systemd then any init or process management system that runs the push server binary with the described environment variables will work.

systemd

For systemd based setups, you can create a systemd service by creating a file named /etc/systemd/system/notify_push.service with the following content.

[Unit]
Description = Push daemon for Nextcloud clients
Documentation=https://github.com/nextcloud/notify_push

[Service]
# Change if you already have something running on this port
Environment = PORT=7867
ExecStart = /path/to/push/binary/notify_push /path/to/nextcloud/config/config.php
# requires the push server to have been build with the systemd feature (enabled by default)
Type=notify
User=www-data
Restart=always
RestartSec=60

[Install]
WantedBy = multi-user.target

If the push server has not been compiled with the optional systemd feature (enabled by default) the Type=notify line has to be removed.

OpenRC

For OpenRC based setups, you can create an OpenRC service by creating a file named /etc/init.d/notify_push with the following content.

#!/sbin/openrc-run

description="Push daemon for Nextcloud clients"

output_log=${output_log:-/var/log/$RC_SVCNAME.log}
pidfile=${pidfile:-/run/$RC_SVCNAME.pid}

command=${command:-/path/to/push/binary/notify_push}
command_user=${command_user:-www-data:www-data}
command_args="--port 7867 /path/to/nextcloud/config/config.php"
command_background=true

depend() {
        need net redis
        use nginx php-fpm8 mariadb postgresql
}

start_pre() {
        checkpath --file --owner $command_user $output_log
}

Adjust the paths, ports and user as needed.

Configuration

The push server can be configured either by loading the config from the nextcloud config.php or by setting all options through environment variables.

Re-using the configuration from nextcloud is the recommended way, as it ensures that the configuration remains in sync.

If using the config.php isn't possible, you can configure the push server by setting the following environment variables:

• DATABASE_URL connection url for the Nextcloud database, e.g. postgres://user:password@db_host/db_name
• DATABASE_PREFIX database prefix configured in Nextcloud, e.g. oc_
• REDIS_URL connection url for redis, e.g. redis://redis_host
• NEXTCLOUD_URL url for the nextcloud instance, e.g. https://cloud.example.com

Or you can specify the options as command line arguments, see notify_push --help for information about the command line arguments.

If a config option is set in multiple sources, the values from the command line argument overwrite values from the environment which in turns overwrites the values from the config.php.

The port the server listens to can only be configured through the environment variable PORT, or --port argument and defaults to 7867. Alternatively you can configure the server to listen on a unix socket by setting the SOCKET_PATH environment variable or --socket-path argument.

Note that Nextcloud load all files matching *.config.php in the config directory in additional to the main config file. You can enable this same behavior by passing the --glob-config option.

TLS Configuration

The push server can be configured to serve over TLS. This is mostly intended for securing the traffic between the push server and the reverse proxy if they are running on different hosts, running without a reverse proxy (or load balancer) is not recommended.

TLS can be enabled by setting the --tls-cert and --tls-key arguments (or the TLS_CERT and TLS_KEY environment variables).

Starting the service

Once the systemd service file is set up with the correct configuration you can start it using

• systemd: sudo systemctl start notify_push
• OpenRc: sudo rc-service notify_push start

and enable it to automatically start on boot using

• systemd: sudo systemctl enable notify_push
• OpenRc: sudo rc-update add notify_push

Every time this app receives an update you should restart the systemd service using

• systemd: sudo systemctl restart notify_push
• OpenRc: sudo rc-service notify_push restart

Alternatively, you can do this automatically via systemctl by creating the following systemd service and path (click to expand)

First create a oneshot service to trigger the daemon restart

/etc/systemd/system/notify_push-watcher.service

[Unit]
Description=Restart Push daemon for Nextcloud clients when it receives updates
Documentation=https://github.com/nextcloud/notify_push
Requires=notify_push.service
After=notify_push.service
StartLimitIntervalSec=10
StartLimitBurst=5

[Service]
Type=oneshot
ExecStart=/usr/bin/systemctl restart notify_push.service

[Install]
WantedBy=multi-user.target

Then create a path job to trigger the restart whenever the push binary is changed

/etc/systemd/system/notify_push-watcher.path

[Unit]
Description=Restart Push daemon for Nextcloud clients when it receives updates
Documentation=https://github.com/nextcloud/notify_push
PartOf=notify_push-watcher.service

[Path]
PathModified=/path/to/push/binary/notify_push
Unit=notify_push-watcher.service

[Install]
WantedBy=multi-user.target

Adjusting the path as needed.

Finally, enable it with

sudo systemctl enable notify_push-watcher.path

Reverse proxy

It is strongly recommended to set up the push service behind a reverse proxy, this both removes the need to open a new port to the internet and handles the TLS encryption of the connection to prevent sending credentials in plain text.

You can probably use the same webserver that you're already using for your nextcloud.

Nginx

If you're using nginx, add the following location block to the existing server block of the nextcloud server.

location ^~ /push/ {
    proxy_pass http://127.0.0.1:7867/;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}

Note that both trailing slashes are required.

Once the nginx configuration is edit you can reload nginx using.

sudo nginx -s reload

Apache

To use apache as a reverse proxy you first need to enable the proxy modules using

sudo a2enmod proxy
sudo a2enmod proxy_http
sudo a2enmod proxy_wstunnel

Then add the following lines to the <VirtualHost> block used for the Nextcloud server.

ProxyPass /push/ws ws://127.0.0.1:7867/ws
ProxyPass /push/ http://127.0.0.1:7867/
ProxyPassReverse /push/ http://127.0.0.1:7867/

Afterwards you can restart apache using

sudo systemctl restart apache2

Caddy v2

handle_path /push/* {
    reverse_proxy http://127.0.0.1:7867
}

Nextcloud app

Once the push server is configured and the reverse proxy setup, you can enable the notify_push app and tell it where the push server is listening.

• enable the app occ app:enable notify_push
• set the url of the push server occ notify_push:setup https://cloud.example.com/push

The app will automatically run some tests to verify that the push server is configured correctly.

Logging

By default, the push server only logs warnings, you can temporarily change the log level with an occ command

occ notify_push:log <level>

Where level is error, warn, info, debug or trace, or restore the log level to the previous value using

occ notify_push:log --restore

Alternatively you can set the log level of the push server in the LOG environment variable.

Metrics

The push server can expose some basic metrics about the number of connected clients and the traffic flowing through the server by setting the METRICS_PORT environment variable.

Once set the metrics are available in a prometheus compatible format at /metrics on the configured port.

Additionally you can manually check the metrics by running the occ notify_push:metrics command, this will function even if you haven't setup METRICS_PORT.

Self-signed certificates

If your nextcloud is using a self-signed certificate then you either need to set the NEXTCLOUD_URL to a non-https, local url, or disable certificate verification by setting ALLOW_SELF_SIGNED=true.

Troubleshooting

When running into issues you should always first ensure that you're on the latest release, as your issue might either already be fixed or additional diagnostics might have been added.

"push server is not a trusted proxy"

• Ensure you haven't added a duplicate trusted_proxies list to your config.php.

• If you're modified your forwarded_for_headers config, ensure that HTTP_X_FORWARDED_FOR is included.

• If your nextcloud hostname resolves do a dynamic ip you can try setting the NEXTCLOUD_URL to the internal ip of the server.

  Alternatively, editing the /etc/hosts file to point your nextcloud domain to the internal ip can work in some setups.

• If you're running your setup in docker and your containers are linked, you should be able to use the name of the nextcloud container as hostname in the NEXTCLOUD_URL

Developing

For information about how to use the push server in your own app or client, see DEVELOPING.md

Test client

For development and testing purposes a test client is provided which can be downloaded from the current release page.
(Click the test_client for your platform to download the binary.)

test_client https://cloud.example.com username password

Note that this does not support two-factor authentication of non-default login flows, you can use an app-password in those cases.