skynet-webportal/docker/nginx/conf.d/include/generate-siapath

# Extract 2 sets of 2 characters from $request_id and assign to $dir1, $dir2
# respectfully. The rest of the $request_id is going to be assigned to $dir3.
# We use those variables to automatically generate a unique path for the uploaded file.
# This ensures that not all uploaded files end up in the same directory, which is something
# that causes performance issues in the renter.
# Example path result: /af/24/9bc5ec894920ccc45634dc9a8065
if ($request_id ~* "(\w{2})(\w{2})(\w+)") {
    set $dir1 $1;
    set $dir2 $2;
    set $dir3 $3;
}