[s3] extension for adding/deleting images on an S3 compatible host

composer.json

@@ -56,7 +56,8 @@
 		"psr/simple-cache"           : "^1.0",
 		"sabre/cache"                : "^2.0.1",
 		"naroga/redis-cache": "dev-master",
-		"tbela99/css": "dev-master"
+		"tbela99/css": "dev-master",
+		"aws/aws-sdk-php": "^3.294"
     },
 
 	"require-dev" : {

ext/s3/config.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shimmie2;
+
+abstract class S3Config
+{
+    public const ACCESS_KEY_ID =     's3_access_key_id';
+    public const ACCESS_KEY_SECRET = 's3_access_key_secret';
+    public const ENDPOINT =          's3_endpoint';
+    public const IMAGE_BUCKET =      's3_image_bucket';
+}

ext/s3/info.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shimmie2;
+
+class S3Info extends ExtensionInfo
+{
+    public const KEY = "s3";
+
+    public string $key = self::KEY;
+    public string $name = "S3 CDN Backend";
+    public string $url = self::SHIMMIE_URL;
+    public array $authors = [self::SHISH_NAME => self::SHISH_EMAIL];
+    public string $license = self::LICENSE_GPLV2;
+    public string $description = "Push post updates to S3";
+}

ext/s3/main.php

@@ -0,0 +1,148 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shimmie2;
+
+require_once "config.php";
+
+class S3 extends Extension
+{
+    public static array $synced = [];
+
+    public function onSetupBuilding(SetupBuildingEvent $event)
+    {
+        global $config;
+
+        $sb = $event->panel->create_new_block("S3 CDN");
+        $sb->add_text_option(S3Config::ACCESS_KEY_ID, "Access Key ID: ");
+        $sb->add_text_option(S3Config::ACCESS_KEY_SECRET, "<br>Access Key Secret: ");
+        $sb->add_text_option(S3Config::ENDPOINT, "<br>Endpoint: ");
+        $sb->add_text_option(S3Config::IMAGE_BUCKET, "<br>Image Bucket: ");
+    }
+
+    public function onCommand(CommandEvent $event)
+    {
+        if ($event->cmd == "help") {
+            print "\ts3-sync <post id>\n";
+            print "\t\tsync a post to s3\n\n";
+            print "\ts3-rm <hash>\n";
+            print "\t\tdelete a leftover file from s3\n\n";
+        }
+        if ($event->cmd == "s3-sync") {
+            if (preg_match('/^(\d+)-(\d+)$/', $event->args[0], $matches)) {
+                $start = (int)$matches[1];
+                $end = (int)$matches[2];
+            } else {
+                $start = (int)$event->args[0];
+                $end = $start;
+            }
+            foreach(Search::find_images_iterable(tags: ["order=id", "id>=$start", "id<=$end"]) as $image) {
+                print("{$image->id}: {$image->hash}\n");
+                ob_flush();
+                $this->sync_post($image);
+            }
+        }
+        if ($event->cmd == "s3-rm") {
+            foreach($event->args as $hash) {
+                print("{$hash}\n");
+                ob_flush();
+                $this->remove_file($hash);
+            }
+        }
+    }
+
+    public function onImageAddition(ImageAdditionEvent $event)
+    {
+        $this->sync_post($event->image);
+    }
+
+    public function onTagSet(TagSetEvent $event)
+    {
+        // pretend that tags were set already so that sync works
+        $orig_tags = $event->image->tag_array;
+        $event->image->tag_array = $event->tags;
+        $this->sync_post($event->image);
+        $event->image->tag_array = $orig_tags;
+    }
+
+    public function onImageDeletion(ImageDeletionEvent $event)
+    {
+        $this->remove_file($event->image->hash);
+    }
+
+    public function onImageReplace(ImageReplaceEvent $event)
+    {
+        $existing = Image::by_id($event->id);
+        $this->remove_file($existing->hash);
+        $this->sync_post($event->image);
+    }
+
+    // utils
+    private function get_client()
+    {
+        global $config;
+        $access_key_id = $config->get_string(S3Config::ACCESS_KEY_ID);
+        $access_key_secret = $config->get_string(S3Config::ACCESS_KEY_SECRET);
+        if(is_null($access_key_id) || is_null($access_key_secret)) {
+            return null;
+        }
+        $endpoint = $config->get_string(S3Config::ENDPOINT);
+        $credentials = new \Aws\Credentials\Credentials($access_key_id, $access_key_secret);
+        return new \Aws\S3\S3Client([
+            'region' => 'auto',
+            'endpoint' => $endpoint,
+            'version' => 'latest',
+            'credentials' => $credentials,
+        ]);
+    }
+
+    private function hash_to_path(string $hash)
+    {
+        $ha = substr($hash, 0, 2);
+        $sh = substr($hash, 2, 2);
+        return "$ha/$sh/$hash";
+    }
+
+    // underlying s3 interaction functions
+    private function sync_post(Image $image)
+    {
+        global $config;
+
+        // multiple events can trigger a sync,
+        // let's only do one per request
+        if(in_array($image->id, self::$synced)) {
+            return;
+        }
+        self::$synced[] = $image->id;
+
+        $client = $this->get_client();
+        if(is_null($client)) {
+            return;
+        }
+        $image_bucket = $config->get_string(S3Config::IMAGE_BUCKET);
+        $friendly = $image->parse_link_template('$id - $tags.$ext');
+        $client->putObject([
+            'Bucket' => $image_bucket,
+            'Key' => $this->hash_to_path($image->hash),
+            'Body' => file_get_contents($image->get_image_filename()),
+            'ACL' => 'public-read',
+            'ContentType' => $image->get_mime(),
+            'ContentDisposition' => "inline; filename=\"$friendly\"",
+        ]);
+    }
+
+    private function remove_file(string $hash)
+    {
+        global $config;
+        $client = $this->get_client();
+        if(is_null($client)) {
+            return;
+        }
+        $image_bucket = $config->get_string(S3Config::IMAGE_BUCKET);
+        $client->deleteObject([
+            'Bucket' => $image_bucket,
+            'Key' => $this->hash_to_path($hash),
+        ]);
+    }
+}