http://:9000 {
	header * {
		-Server
	}
	root D:/Images

	@thumbnail {
		path_regexp thumb /.+\.(jpg|jpeg|png|gif|bmp|tif|tiff|webp)$
	}

	handle @thumbnail {
		image_filter {
			fit {query.w} {query.h}
		}
	}

	file_server
}

http://localhost {
	header * {
		-Server
	}
	root * D:/Images
	route {
		
		reverse_proxy /api/operation/downfile http://localhost:205 {
			@accel header X-Accel-Redirect *
			handle_response @accel {
				rewrite * {rp.header.X-Accel-Redirect}
				header {
					#To realize the download after the file name is changed, add the Content-Disposition at the bottom. 
					#If it is not added, it can realize the authentication before the file acquisition (through the file ID),  Can be used for preview
					Content-Disposition {rp.header.Content-Disposition}
					Water-Mark {rp.header.Water-Mark}
				}
				reverse_proxy [::1]:9000
			}
		}

		try_files {path} /index.html

		file_server
	}
}

#   C# Code if you need I can also provide the go code
#The code returns the true path of the file through the response header. With the watermark to be added, can caddy add the #watermark to the returned image when forwarding to localhost: 9000

# public IActionResult DownFile() {
# 	//If the file does not exist, point to a default picture

# 	//return Redirect("http://localhost:8001/UserFile/notfind.jpg");

# 	//HttpContext.Response.Headers["Content-type"] = "application/octet-stream";
# 	var _fileName = HttpUtility.UrlEncode("imagerealName.jpg");
# 	HttpContext.Response.Headers["Content-Disposition"] = "attachment;filename=" + _fileName;

# 	HttpContext.Response.Headers["X-Accel-Redirect"] = "D:/Images/aaaa.jpg";
#   HttpContext.Response.Headers["Water-Mark"] = "UserRealId";

# 	HttpContext.Response.StatusCode = 200;

# 	return Json("");
# }

{
    order image_ filter before file_ server
}

@thumbnail {

    path_ regexp thumb /.+\. (jpg|jpeg|png|gif|bmp|tif|tiff|webp)$

    query w=*

    query h=*

}

image_ filter @thumbnail {

    fit {query.w} {query.h}

}

{
    order image_ filter before file_ server
}

http://localtest.xxx.cn {

    root * D:/GitHub/dist

    route {

        reverse_ proxy /api/* http://192.168.1.123:1205

        try_ files {path} /index.html

        file_ server

   }

   @thumbnail {

        path_ regexp thumb /.+\. (jpg|jpeg|png|gif|bmp|tif|tiff|webp)$

        query w=*

        query h=*

  }


    handle @thumbnail {

    image_ filter {

        fit {query.w} {query.h}

    }

}

{

order image_ filter before file_ server

order cache before rewrite

}

http://localtest.xxx.cn {

    root * D:/GitHub/dist

    route {

        reverse_ proxy /api/* http://192.168.1.123:1205

        try_ files {path} /index.html

        file_ server

    }

    @thumbnail {

        path_ regexp thumb /.+\. (jpg|jpeg|png|gif|bmp|tif|tiff|webp)$

    }

    handle @thumbnail {

        reverse_ proxy [::1]:9000 # prevents multiple "Server: Caddy" response header

    }

}



http://:9000 { # internal address only accessable from the server itself to transform images

   bind ::1 # local ipv6 address (same as 127.0.0.1 for ipv4)

    #cache {

        #ttl 1000s

    #}



#header Cache-Control "max-age=86400" # keep 1 day in cache

    root D:/GitHub/dist

    @thumbnail {

         path_ regexp thumb /.+\. (jpg|jpeg|png|gif|bmp|tif|tiff|webp)$

    }

    handle @thumbnail {

        image_ filter {

            fit {query.w} {query.h}

        }

    }

}