---

labels:

- 'Stage-Stable'

summary: Publish to PubSub nodes from via HTTP POST/WebHooks

---

# 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.

``` {.bash}

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"}'

```

# 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:

``` {.lua}

-- 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](https://www.w3.org/TR/2018/REC-websub-20180123/) [Authenticated

Content

Distribution](https://www.w3.org/TR/2018/REC-websub-20180123/#authenticated-content-distribution)

authentication is used.

``` {.lua}

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.

::: {.alert .alert-danger}

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](https://xmpp.org/extensions/xep-0060.html#owner-affiliations), in

trunk since [revision

384ef9732b81](https://hg.prosody.im/trunk/rev/384ef9732b81), so

affiliations can be configured with a capable client.

It can however be done from another plugin:

``` {.lua}

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");

```