view mod_ogp/README.markdown @ 4877:adc6241e5d16

mod_measure_process: Report the enforced limit The soft limit is what the kernel actually enforces, while the hard limit is is how far you can change the soft limit without privileges. Unless the process dynamically adjusts the soft limit, knowing the hard limit is not as useful as knowing the soft limit. Reporting the soft limit and the number of in-use FDs allows placing alerts on expressions like 'process_open_fds / process_max_fds >= 0.95'
author Kim Alvefur <zash@zash.se>
date Tue, 18 Jan 2022 18:55:20 +0100
parents 09f0911c735d
children
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# mod_ogp

This module adds [Open Graph Protocol](https://ogp.me) metadata to URLs sent inside a MUC.

With mod_ogp enabled, when a user sends a URL in a MUC (where the message has its `id` equal to its `origin-id`), the module calls the URL and parses the result for `<meta>` html tags that have any `og:...` properties.
If it finds any, it sends a [XEP-0422 fastening](https://xmpp.org/extensions/xep-0422.html) applied to the original message that looks like:

```xml
<message id="example" from="chatroom@muc.example.org" to="user@chat.example.org/resource">
<apply-to xmlns="urn:xmpp:fasten:0" id="origin-id-X">
<meta xmlns="http://www.w3.org/1999/xhtml" property="og:title" content="The Rock"/>
<meta xmlns="http://www.w3.org/1999/xhtml" property="og:url" content="https://www.imdb.com/title/tt0117500/"/>
<meta xmlns="http://www.w3.org/1999/xhtml" property="og:image" content="https://ia.media-imdb.com/images/rock.jpg"/>
</apply-to>
</message>
```

The module is intentionally simple in the sense that it is basically a transport for https://ogp.me/

Configuration
-------------

You can present an allowlist or denylist of domains for which OGP metadata will be fetched
via the `ogp_domain_allowlist` and `ogp_domain_denylist` settings repectively.

For example:

```lua
Component "muc.example.org" "muc"
  modules_enabled = { "ogp" }
  ogp_domain_allowlist = { "prosody.im" }
```