WP Offload S3 uses a StreamWrapper to enable editing of remote files on S3, using the s3:// protocol.
You’re likely getting the error because:
a) Something is stopping the s3:// protocol from being registered.
or
b) allow_url_fopen has been turned off.
Both of these are likely down to some sort of security setup.
I need to revisit this again, still not able to edit images. Clearly, if everyone else can edit images and we cannot, there must be something missing on our server. I have set up a vanilla CentOS 7.4 server with all updates running Apache 2.4.6 with PHP 7.2 and installed WordPress 4.9.4 all from scratch. I disabled selinux and opened http, https, ssh and ftp in Firewalld. I am using the Twenty Seventeen theme with only the WP Offload S3 Lite v1.3.2 plugin installed and activated. The allow_url_fopen is on, here is the complete PHP info:
http://wp.webtent.net/info.php
I go to the Media Library and upload an image, then click to Edit Image and rotate. When I save, the error in the Apache error log is:
[Mon Mar 26 10:23:11.742252 2018] [php7:warn] [pid 11843] [client 96.254.71.164:49223] PHP Warning: fopen(http://s3.amazonaws.com/wmnf/wp-test/uploads/2017/12/06224532/Linux-Music-e1522074191942.jpg): failed to open stream: HTTP wrapper does not support writeable connections in /var/www/html/wp-includes/class-wp-image-editor.php on line 407, referer: http://wp.webtent.net/wp-admin/upload.php?item=5&mode=edit
That’s it, very easy to duplicate this issue. If allow_url_open is On, then the issue with this stock set up as I described is preventing the s3 protocol from being registered as suggested? How can images be uploaded successfully to the S3 in that case? Or could someone suggest what I am missing?
