push-sub

push-sub

push-sub is a daemon which maintains subscriptions with PubSubHubbub (PuSH) hubs and calls specified commands when messages arrive. PuSH is a server-to-server update protocol. It's used to notify servers about changes on other servers. This tool aims to make receiving PuSH updates secure and easy.

Usage

Create a config file and run push-sub. Here's an example config file which to receives updates from a youtube channel topic and dumps them into /tmp/pub.txt:

# config.toml
address="127.0.0.1:17889"
basepath="https://hub.ydns.eu/"

[subscriptions.youtube_channel]
topic="https://www.youtube.com/xml/feeds/videos.xml?channel_id=UCF8wOZvgrBZzj4netRo3m2A"
hub="https://pubsubhubbub.appspot.com"
command=["/usr/bin/tee", "/tmp/pub.txt"]

For more configuration options, check out config.go.

Now run push-sub and wait for messages. Make sure that basepath is publically visible and points to address. When a message arrives, command will be executed and the message will passed to it through standard input.

INFO[0000] reading config: ./config.toml                
INFO[0000] discovering hub                                  name="youtube_channel"
INFO[0000] discovered hub: https://pubsubhubbub.appspot.com name="youtube_channel"
INFO[0000] registered endpoint="https://hub.ydns.eu/ZC8IRIuuaObmkaOx1zC8NhxjGDJ0E6n4FT7TjMAyyot3f6zxvupGacl56isMR6rGkHebwRwitNXObtAzjYxBKt0ze3k9XTD9q1i" name="youtube_channel"
INFO[0000] listening on 127.0.0.1:17889
INFO[0001] subscribing                                   name="youtube_channel"
INFO[0001] subscribed                                    name="youtube_channel"
INFO[0013] received message                              name="youtube_channel"
INFO[0013] running command                               args=[/usr/bin/tee /tmp/pub.txt] name="youtube_channel"

Installing

go get github.com/0xcaff/sub/push-sub

If you don't have go, check out the releases for prebuilt binaries.

Daemonizing (Systemd)

Here is a systemd unit file to run push-sub as a daemon:

[Unit]
Description=PubSubHubbub Subscriber
Requires=network-online.target

[Service]
Type=simple
ExecStart=/opt/push-sub -config /opt/push-sub.toml

[Install]
WantedBy=multi-user.target