Changing the filename of the result

[vinclou]

Thank you 🙏

I had a chance to get back to working on experimenting with the ImgProxy server and I have a question:

Suppose I have the following part of the content model:

"assets": { // assets is a part of another general model
  "baseUrl": "https://{my.cdn.host}/c/e/B_SP", // misc
  "thumb":  {
    "src": "https://{my.cdn.host}/c/e/B_SP/thumb.jpg", // original image (only for reference)
    "srcset":  [ // these are generated by the backend on-the-fly upon request
      {
        "url": "https://{server.gen.signed.imgproxy.url}/fn:thumb_1x/{other}/thumb.jpg", // results in thumb_1x.jpg or whatever the extension is
        "x": 1,  
        "w": 128
      },
      {
        "url": "https://{server.gen.signed.imgproxy.url}/fn:thumb_2x/{other}/thumb.jpg", // same
        "x": 2,
        "w": 256
      }, // ..etc based on dpi requirements
    ]
  },
}

Problem Space:

I want to be able to generate the srcset on the fly, but I don't want to store the images in the blob storage, I want to be able to generate them on the fly and cache them on the CDN.

Background:

Given I have my blob storage configuration, my server is able to programatically able to determine
the file name, there like 3 - 5 different file names that I need to generate, but the config
for imgproxy is the same, the only thing that changes is the file name.

Question:

Does ImgProxy support renaming the output file in the HTTP response? For example, can ImgProxy return a processed image with a URL ending in thumb_1x.jpg while the actual source file remains thumb.jpg in the storage? Is this renaming just a URL convention, or does it reflect in the HTTP response headers (e.g., in the Content-Disposition header)?

The following is within the docs:

filename:%filename:%encoded
fn:%filename:%encoded

So I suppose I can use the filename option to rename the file,
but I am not sure if I'm applying transformation correctly.

Here's the req to my local imgproxy server:

http://localhost:8080/BaXyTjATDUtsKBK2KLOcv3jpin-uUWOvvKGgj3GuNzI/rs:fit:400:0:0/g:ce/fn:test/plain/local:///ex/C/extraLarge.png

Response Headers:

HTTP/1.1 200 OK
Cache-Control: max-age=31536000, public
Content-Disposition: inline; filename="test.avif"
Content-Length: 12289
Content-Security-Policy: script-src 'none'
Content-Type: image/avif
Expires: Thu, 28 Nov 2024 01:57:49 GMT
Server: imgproxy
Vary: Accept
X-Request-Id: VxMbNw2jcrvRe2uL4mjzR
Date: Wed, 29 Nov 2023 01:57:49 GMT

Request Headers:

GET /BaXyTjATDUtsKBK2KLOcv3jpin-uUWOvvKGgj3GuNzI/rs:fit:400:0:0/g:ce/fn:test/plain/local:///ex/C/extraLarge.png HTTP/1.1
Host: localhost:8080
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/119.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Pragma: no-cache
Cache-Control: no-cache

The Content-Disposition: inline; filename="test.avif" is set properly.

The response has the same file name as the source file, so I am doing something wrong?

[DarthSim]

Hey @vinclou!

Sorry, but I don't really understand what you're trying to achieve. Could you explain what you mean by response filename? The only filename HTTP response can have is one specified in the Content-Disposition header, and this is exactly what the filename option changes.

[vinclou]

I was wondering if it's possible to rename the transformed file;

But, I think I'm just on the wrong path overall & might not even need this.