mod_pubsub_post

Introduction

This module is a fairly generic WebHook receiver that lets you easily publish data to PubSub using a HTTP POST request. The payload can be Atom feeds, arbitrary XML, or arbitrary JSON. The type should be indicated via the Content-Type header.

JSON example

curl http://localhost:5280/pubsub_post/princely_musings \
    -H "Content-Type: application/json" \
    --data-binary '{"musing":"To be, or not to be: that is the question"}'

Atom example

curl http://localhost:5280/pubsub_post/princely_musings \
    -H "Content-Type: application/xml" \
    --data-binary '<feed xmlns="http://www.w3.org/2005/Atom">
        <entry><title>Hello</title></entry></feed>'

Configuration

All settings are optional.

Actor identification

First we have to figure out who is making the request. This is configured on a per-node basis like this:

-- Per node secrets
pubsub_post_actors = {
    princely_musings = "hamlet@denmark.lit"
}
pubsub_post_default_actor = "nobody@nowhere.invalid"

pubsub_post_default_actor is used when trying to publish to a node that is not listed in pubsub_post_actors. Otherwise the IP address of the connection is used.

Authentication

WebSub Authenticated Content Distribution authentication is used.

pubsub_post_secrets = {
    princely_musings = "shared secret"
}
pubsub_post_default_secret = "default secret"

pubsub_post_default_secret is used when trying to publish to a node that is not listed in pubsub_post_secrets. Otherwise the request proceeds with the previously identified actor.

If configured without a secret and a default actor that has permission to create nodes the service becomes wide open.

Authorization

Authorization is handled via pubsub affiliations. Publishing requires an affiliation with the publish capability, usually "publisher".

Setting up affiliations

Prosodys PubSub module supports setting affiliations via XMPP, in trunk since revision 384ef9732b81, so affiliations can be configured with a capable client.

It can however be done from another plugin:

local mod_pubsub = module:depends("pubsub");
local pubsub = mod_pubsub.service;

pubsub:create("princely_musings", true);
pubsub:set_affiliation("princely_musings", true, "127.0.0.1", "publisher");