You might see that the Dropbox Community team have been busy working on some major updates to the Community itself! So, here is some info on what’s changed, what’s staying the same and what you can expect from the Dropbox Community overall.
Forum Discussion
Error 400 when trying to download a file
Hello, I'm using Dropbox for OTA. It worked for long time up until couple of weeks ago. Now, connection is established, folder list is downloaded, but when trying to download a file, I'm receivi...
sz3324 wrote:...
Is there a way to get a log from your server that shows the format of the received HTTP request?
...
Hi sz3324,
Dropbox (and most other similar services) doesn't provide such logs usually, so server side logs gonna be unavailable to you, as Greg said. In addition, on embedded systems, client side logs are relatively limited where available at all. Usually some coding equilibristics are needed to redirect log to external logging server in such cases, cosa limited local resources.
In spite, there's an easy trick that let you evaluate the transaction without significant effort and as accurate as possible. Just trace the HTTP of interest itself. 😉 An easy way is using pseudo server as denoted here. Make needed temporary changes to the troublesome request (the download - in your case). In addition you may use some helper tool - like Wireshark, for instance.
Hope this helps.
Thanks. I'll try a pseudo server
Hello,
Here is the problematic request (the one acknowledged with error 400), captured locally just before submitted:
'list_folder' request:
POST /2/files/list_folder HTTP/1.1<CR><LF>
Content-Type: application/json<CR><LF>
Authorization: Bearer sl.Bwg31qNyvs2KjuANe6wfTrBJu2LBO7mrVltkFc9dSYg9VCVfg4NhKyPbZ4Es5QSy2BMHTlno5OBgiF14RAOtFCHpbyWuJ1T-EY5jxgKIbOhDv1Wrq4DwXJR6SUHabSP4AdAHwTM<CR><LF>
Host: api.dropboxapi.com<CR><LF>
Content-Length: 41<CR><LF>
<CR><LF>
{"path": "/ota_bundle_office","limit": 1}<CR><LF>'list_folder' response:
{"entries": [{".tag": "file", "name": "20240221072512_CC3220SF.tar", "path_lower": "/ota_bundle_office/20240221072512_cc3220sf.tar", "path_display": "/ota_bundle_office/20240221072512_CC3220SF.tar", "id": "id:dIosUmeVHMoAAAAAAAABVA", "client_modified": "2024-02-21T05:31:31Z", "server_modified": "2024-02-21T05:31:31Z", "rev": "01611dda3b09665000000026de23b50", "size": 573440, "is_downloadable": true, "content_hash": "c31073c7b9ea0a3fa69ff61a6ab8d80e5b51d9fa4ef8eee49384cc5b64071406"}], "cursor": "AAGUl6koiJNa5jclgopptYqRLLcfflMtyH4JCF0vnMrlWQ51eowHqMHoXjqHlaDMXOrhfzWY3yBqNRuGqrAgeS2n-Yf9OlPbeL03QBJ9uw3s2sAm-dAMk9r5JiK8ypWoLwhrYUtVsesIJ_8wu9N1J00J_kZpWsHG1iiuws4AmBtggVPtTKBNtD8TIZMGwQ9z1RrZtbYuHmoMXZ_Vm8a8CRDYen9zNkZsMRHsMOCUkj0b9w", "has_more": false}0<LF><CR>
problematic request:
POST /2/files/get_temporary_link HTTP/1.1<CR><LF>
Content-Type: application/json<CR><LF>
Authorization: Bearer sl.Bwg31qNyvs2KjuANe6wfTrBJu2LBO7mrVltkFc9dSYg9VCVfg4NhKyPbZ4Es5QSy2BMHTlno5OBgiF14RAOtFCHpbyWuJ1T-EY5jxgKIbOhDv1Wrq4DwXJR6SUHabSP4AdAHwTM<CR><LF>
Host: api.dropboxapi.com<CR><LF>
Content-Length: 58<CR><LF>
<CR><LF>
{"path": "/ota_bundle_office/20240221072512_CC3220SF.tar"}<CR><LF>error 400 response:
<!DOCTYPE html><LF>
<html><LF>
<head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><LF>
<meta name="viewport" content="width=device-width, initial-scale=1" /><LF>
<title>Dropbox - 400</title><LF>
<link href="https://cfl.dropboxstatic.com/static/metaserver/static/css/error.css" rel="stylesheet" type="text/css"/><LF>
<link rel="shortcut icon" href="https://cfl.dropboxstatic.com/static/images/favicon.ico"/><LF>
</head><LF>
<body><LF>
<div class="figure"><LF>
<img src="https://assets.dropbox.com/www/en-us/illustrations/spot/target-miss.svg" alt="Error: 400"/><LF>
</div><LF>
<div id="errorbox"><LF>
<h1>Error (400)</h1>Something went wrong. Don't worry, your files are still safe and the Dropbox team has been notified. Check out our <a href="https://status.dropbox.com">Status Page</a> to see if there is a known incident, our <a href="https://www.dropbox.com/help">Help Center</a> and <a href="https://forums.dropbox.com">forums</a> for help, or head back to <a href="https://www.dropbox.com/home">home</a>.<LF>
</div><LF>
<LF>
</body><LF>
</html><LF>
<LF><CR>Can you please help identify the incompatible format part? Thanks
Hm..🤔 In general everything seems fine and no error should be expected. There is one exception though - one more symbol:
sz3324 wrote:..., "has_more": false}0<LF><CR>
...
The zero here is definitely not on place! If this is not some copy/paste mistake, you may have some trouble in your system that you have to debug. In all cases, you may print responses headers out and post here 'x-dropbox-request-id' header. This will let additional error tracing.
sz3324 wrote:...
Can you please help identify the incompatible format part? Thanks
The path's format is all right. There should be something "behind the scene" though, as I said. By the way to see everything follow my directions exactly - the output, you posted, does NOT come from pseudo server since incomplete!
Good luck.
- Greg-DB
Dropbox Staff
sz3324 As Здравко said, the request appears correct. I tried replicating the request as shown here and it did not fail like that for me, so please check that that's exactly what you're actually sending.
Here is a capture of the request when redirected to AWS (API Gateway service). It looks perfectly correct:
(bdc789db-0418-470d-8cd0-c875d80b44b3) Method request headers: {Authorization=*******************************************************************************************************************************************CLnyJw, X-Forwarded-Proto=https, X-Forwarded-For=2.53.174.13, Host=d13k3bi9ke.execute-api.us-east-1.amazonaws.com, X-Forwarded-Port=443, X-Amzn-Trace-Id=Root=1-65e41272-37ecaf0e7538265a0082a13f, Content-Type=application/json}
(bdc789db-0418-470d-8cd0-c875d80b44b3) Method request body before transformations: {
"path": "/ota_bundle_office/20240221072512_CC3220SF.tar"
}Adding the fact that the request is perfectly decoded by other servers (I tried AWS and httpdump.app) to the fact that it worked perfectly with Dropbox.com up until couple of weeks ago, might show that a recent change that you made in your server is the root cause for this issue. I do not think that this is a format issue. Please advise. Thanks
About Dropbox API Support & Feedback
Find help with the Dropbox API from other developers.
