What are the ways to transfer an image to a second hosting?

Question

PHP

Hello community!

There are initial data:
1. Hosting with a site, current, it stores site statics, user avatars and other trifles
- the domain (for example) example.com
- the volume is limited to 2 GB (SSD is all business), increasing the volume is expensive and only up to 10 GB
- hoster, let's call it for example (Seagull)
2. The second hosting, it is planned to store images for the site blogs
- a subdomain, respectively, img.examle.com
- everything that is not needed is disabled (mysql, php, etc.) only domains, ftp, ssh are left
- places 150 GB maximum speed, cheap enough, so you can buy another 150, etc. with img2 img3 imgN subdomains
- let's call the hoster another, for example (Eagle)

Task:
It is planned to make multi-upload of images into the theme using Jquery Uploadify, output individually after successful upload, BB insert code in the textarea field, cropping if necessary. And much more (but that's a completely different story) I

'm specifically interested in the method of transferring images to third-party hosting.
I read a lot, I implemented the system on php-ftp, but this system is limited by the number of ftp connections and may stop working as soon as we hit the limit.
It is possible, in principle, to implement the receiving script on the other side in php, but this needs to be done to protect against "enemies", I would like to have the control system on the main hosting.
I also read about sockets, I haven't studied them in detail yet.
Perhaps someone already had experience in such an implementation, what would you recommend useful?
Where can you read?

PS*
I must say right away that VDS, VPS are not considered because the budget is very limited. We do our best with minimal effort.

Answer 1

Not exactly a pretty option, but it should work.
Set up nginx in Orel so that it gives some kind of stub in the style of "Now your image is being processed, it will be available in a while."
When you upload a picture, you put it in a specific folder in Seagull. And on the crown you distill the pictures from this folder to the Eagle.
Or you can go further, configure nginx in Orel so that it searches for files first in this folder, and then in Seagull.