10up / image-generator

Generates missed thumbnails for images on the fly.

Image Generator

Nginx config

location ~ \.(gif|jpg|png) {
	try_files $uri @img_proxy;
}

location @img_proxy {
	rewrite ^(.*)$ /wp-admin/admin-ajax.php?action=generate_image;
}

Amazon S3 config

To make it working with Amazon S3 you need to enable website hosting for your bucket in S3 console and update redirection rules by adding following snippet:

<RoutingRules>
	<RoutingRule>
		<Condition>
			<HttpErrorCodeReturnedEquals>403</HttpErrorCodeReturnedEquals >
		</Condition>
		<Redirect>
			<HostName>yousite.com</HostName>
			<ReplaceKeyPrefixWith>wp-admin/admin-ajax.php?action=generate_image&amp;provider=aws&amp;image=</ReplaceKeyPrefixWith>
			<HttpRedirectCode>302</HttpRedirectCode>
		</Redirect>
	</RoutingRule>
</RoutingRules>

Please, pay attention to the HttpErrorCodeReturnedEquals parameter. It might accept either 403 or 404 code depending on a bucket settings. Also if you use S3 Uploads plugin, then you need to use S3Uploads provider name instead of aws as shown above. Finally if you stick with aws provider, then you need to define ACCESS KEY, SECRET, REGION and BUCKET constants in your wp-config.php file:

define( 'AWS_ACCESS_KEY_ID', '...' );
define( 'AWS_SECRET_ACCESS_KEY', '...' );
define( 'AWS_S3_REGION', '...' );
define( 'AWS_S3_BUCKET', '...' );