gerben
/
nextcloud-memento

# Memento — Nextcloud web archive server

If you host snapshots of web pages on your Nextcloud, this app enables any client that speaks the
Memento protocol to access these snapshots. It is part of an experiment aiming to create personal
web archives.

The Memento protocol ([RFC7089][]) is widely used to ask archives (such as the Internet Archive's
[Wayback Machine][]) for their copies of web pages. For example, a client (e.g. a browser extension)
may ask an archive whether it has a copy of `https://nextcloud.com` from around July last year, and
—if successful— will be redirected to the closest match.

## Snapshot format

Currently this app only supports snapshots that are stored as plain html files (supporting [WARC][]
files could be a future addition). It recognises a file as being a snapshot if the file contains a
`<link>` to the location of the original page; such snapshots can be created using [Freeze-dry][].

For example, assume you have an html file `example.html`. If this file contains a `<link
rel="origin" href="https://example.org">` in its `<head>`, it will be recognised as a snapshot of
`https://example.org`.

## Usage

This app presents a Memento TimeGate at the `/timegate/{url}` route. Assuming that the
`example.html` of the above example resides in a shared folder with URL `/s/123abc`, then visiting
`/apps/memento/timegate/https://example.org` would redirect you to
`/apps/raw/s/123abc/example.html` (hence you need the [Raw][] app as well).

Note that a private file will only be found if the client supplies login credentials (i.e. the
session cookie). Otherwise, only files/folders for which 'Share link' is enabled will be scanned.

In a typical Memento client (e.g. the [Memento Time Travel][] browser extension), you would add your
archive as `https://my-nextcloud/apps/memento/timegate/` (of course first replace `my-nextcloud`
appropriately).

A TimeMap is also exposed, at the `/timemap/{url}` route, to list all available snapshots of a URL.
For details, look at the documentation of the Memento protocol ([RFC7089][]).

The app normally looks for shared snapshots of all users on the Nextcloud instance. To limit results
to those of a single user, use `.../u/{userid}/timegate/...` instead of `.../timegate/...` (and
likewise for `timemap`).

## Requirements

Besides of course Nextcloud itself (tested on version 14), this app requires the app [Raw][] to also
be installed, in order to host the snapshots.

## Installation

Clone this repo into your Nextcloud installation's `/apps` (or `/custom_apps`) folder, ensuring the
folder's name is `memento`:

    git clone https://code.treora.com/gerben/nextcloud-memento memento

Then log into Nextcloud as admin, find and enable it in the list of apps.

This app is currently not published in the Nextcloud app store.


[Memento Time Travel]: https://addons.mozilla.org/en-US/firefox/addon/memento-timetravel/
[RFC7089]: https://tools.ietf.org/html/rfc7089
[Wayback Machine]: https://web.archive.org/
[WARC]: https://iipc.github.io/warc-specifications/specifications/warc-format/warc-1.1/
[Freeze-dry]: https://github.com/WebMemex/freeze-dry
[Raw]: https://code.treora.com/gerben/nextcloud-raw