Jaidyn Ann
71fa674ce3
Now that LitePub has its own classes (rather than modifying those of Activity-Vocabulary), this is necessary.
152 lines
5.6 KiB
Common Lisp
152 lines
5.6 KiB
Common Lisp
;;;; simple-server: A bare-bones example ActivityPub instance.
|
||
|
||
;; Written in 2024 by Jaidyn Levesque <jadedctrl@posteo.at>
|
||
;;
|
||
;; To the extent possible under law, the author(s) have dedicated
|
||
;; all copyright and related and neighboring rights to this
|
||
;; software to the public domain worldwide. This software is
|
||
;; distributed without any warranty.
|
||
;;
|
||
;; You should have received a copy of the CC0 Public Domain
|
||
;; Dedication along with this software. If not, see
|
||
;; <http://creativecommons.org/publicdomain/zero/1.0/>.
|
||
|
||
(defpackage #:activitypub-example
|
||
(:use #:cl)
|
||
(:export :start-server :seed)
|
||
;; Note that we use a nickname for the ActivityStreams vocab!
|
||
;; I recommend doing likewise; save yourself some typing!
|
||
(:local-nicknames (:ass :activity-servist/vocab/activity)
|
||
(:lp :activity-servist/vocab/litepub)))
|
||
|
||
(in-package #:activitypub-example)
|
||
|
||
|
||
;;; Globals
|
||
;;; ————————————————————————————————————————
|
||
(defvar *store* (make-hash-table :test #'equal)
|
||
"Our “object-store” — stores all ActivityPub objects, mapped by their IRI @ID.")
|
||
|
||
(defvar *config*
|
||
'(:host "http://localhost:8080" :address "127.0.0.1" :port 8080 :fetch fetch))
|
||
|
||
(defvar *user-id-format* "~A/users/~A"
|
||
"The format we use for user’s @IDs/URIs.
|
||
The first parameter is the protocol+host, and the second is the username.
|
||
For example: “https://localhost:8080/users/lena”.")
|
||
|
||
|
||
|
||
;;; Invocation
|
||
;;; ————————————————————————————————————————
|
||
(defun start-server ()
|
||
"Start the server; simple and to-the-point."
|
||
(clack:clackup
|
||
(lambda (env)
|
||
(let ((activity-servist:*config* *config*))
|
||
(activity-servist:server env)))
|
||
:server 'woo
|
||
:address (getf *config* :address)
|
||
:port (getf *config* :port)))
|
||
|
||
(defun seed ()
|
||
"Seed our server with some random users, for testing purposes."
|
||
(save (make-user "maria" "Maria ♥"))
|
||
(save (make-user "melanie" "Melanie >:o"))
|
||
(save (make-user "jorge" "Jorge 🦆")))
|
||
|
||
|
||
|
||
;;; Activity-Servist callbacks
|
||
;;; ————————————————————————————————————————
|
||
(defun fetch (uri)
|
||
"activity-servist callback); returns the JSON-LD-OBJECT of the given @ID or URI.
|
||
This example server simply stores objects in a hash-table mapping IDs to objects."
|
||
(let ((id (or (uri->id uri) uri)))
|
||
(gethash id *store*)))
|
||
|
||
|
||
|
||
;;; ID-management
|
||
;;; ————————————————————————————————————————
|
||
(defun uri->id (uri-str)
|
||
"Returns an object’s @ID corresponding to the URI string.
|
||
For most cases, returning URI-STR directly is what you want. But there are two exceptions:
|
||
• Account URIs of format “acct:username@host.tld”, as used by WebFinger.
|
||
• Aliases, if an object can be accessed through several URIs.
|
||
|
||
This example only handles the first exception, acct: URIs."
|
||
(let* ((uri (quri:uri uri-str))
|
||
(scheme (quri:uri-scheme uri)))
|
||
(if (or (not scheme)
|
||
(equal scheme "acct"))
|
||
(acct-uri->id uri)
|
||
uri-str)))
|
||
|
||
(defun acct-uri->id (uri)
|
||
"Helper-function for URI->ID. Returns the @ID of an acct:-format URI.
|
||
That is, an “acct:username@host.tld” URI."
|
||
(let* ((path (quri:uri-path uri))
|
||
(sans-preceding-@ (if (str:starts-with-p "@" path)
|
||
(subseq path 1)
|
||
path)))
|
||
(destructuring-bind (user host)
|
||
(str:split "@" sans-preceding-@)
|
||
(format nil *user-id-format*
|
||
(host-w-scheme host) user))))
|
||
|
||
(defun host-w-scheme (hostname)
|
||
"Helper-function for ACCT-URI->ID. From a hostname, returns “scheme://hostname”.
|
||
If it matches our configured :HOST (in *CONFIG*), simply returns :HOST’s value.
|
||
Otherwise, assume “https”."
|
||
(let ((our-host (getf *config* :host)))
|
||
(if (equal (quri:uri-host (quri:uri our-host)) hostname)
|
||
our-host
|
||
(format nil "https://~A" hostname))))
|
||
|
||
|
||
|
||
;;; Data-management
|
||
;;; ————————————————————————————————————————
|
||
(defun save (obj)
|
||
"Save an object to our object-store, *STORE*."
|
||
(setf (gethash (json-ld:@id obj) *store*) obj))
|
||
|
||
|
||
|
||
;;; Users
|
||
;;; ————————————————————————————————————————
|
||
(defclass user (ass:person lp:object)
|
||
((inbox
|
||
:accessor user-inbox
|
||
:initform nil
|
||
:documentation "A list of objects in the user’s inbox.")
|
||
(outbox
|
||
:accessor user-outbox
|
||
:initform nil
|
||
:documentation "A list of objects in the user’s outbox.")
|
||
(following
|
||
:accessor user-following
|
||
:initform nil
|
||
:documentation "A list of Actor objects that the user is following.")
|
||
(followers
|
||
:accessor user-followers
|
||
:initform nil
|
||
:documentation "A list of Actor objects that follow the user.")))
|
||
|
||
(defun make-user (username nickname)
|
||
"Create a USER of the given USERNAME and NICKNAME.
|
||
The ID and ENDPOINTS are derived using the parameter USERNAME and the global *USER-ID-FORMAT*."
|
||
(let ((obj (make-instance 'user))
|
||
(uri (format nil *user-id-format*
|
||
(getf *config* :host) username)))
|
||
(flet ((sub-uri (path)
|
||
(format nil "~A/~A" uri path)))
|
||
(setf (ass:name obj) username)
|
||
(setf (json-ld:@id obj) uri)
|
||
(setf (ass:inbox obj) (sub-uri "inbox"))
|
||
(setf (ass:outbox obj) (sub-uri "outbox"))
|
||
(setf (ass:following obj) (sub-uri "following"))
|
||
(setf (ass:followers obj) (sub-uri "followers")))
|
||
obj))
|