Re: [PATCH proxmox] s3-client: copy_object: always set Content-Type header

[Hannes Laimer <h.laimer@proxmox.com>]

On 2026-03-12 13:39, Christian Ebner wrote:
> On 3/11/26 10:56 AM, Hannes Laimer wrote:
>> Some S3 providers drop all source metadata, including Content-Type,
>> when using x-amz-metadata-directive REPLACE unless it is explicitly
>> provided in the copy request. This caused s3_refresh to fail with
>> "missing header 'content-type'" on such providers when fetching
>> objects moved via copy_object.
>>
>> Setting Content-Type explicitly is a no-op for providers that already
>> preserve it, so this is safe regardless of the provider.
> 
> This should further state that it only acceptable  to set the header
> unconditionally here, since the current s3 client implementation does
> set it unconditionally as well. Which however raises the inconsistency
> as mentioned below.
> 
>>
>> Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
>> ---
>> did notice this with RustFS, MinIO did not have that problem
>>
>>   proxmox-s3-client/src/client.rs | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/proxmox-s3-client/src/client.rs b/proxmox-s3-client/src/
>> client.rs
>> index 81645716..baa8345e 100644
>> --- a/proxmox-s3-client/src/client.rs
>> +++ b/proxmox-s3-client/src/client.rs
>> @@ -602,6 +602,7 @@ impl S3Client {
>>               .method(Method::PUT)
>>               .uri(self.build_uri(&destination_key, &[])?)
>>               .header("x-amz-copy-source",
>> HeaderValue::from_str(&copy_source)?)
>> +            .header(header::CONTENT_TYPE, "binary/octet-stream")
> 
> This should be `application/octet-stream` [0], there is no `binary/
> octet-stream` according to [1]. While checking this, I did notice the
> original Content-Type in put_object() is set to `binary/octet` which is
> also wrong. So both should be fixed and aligned.
> 

thanks for taking a look, makes sense! Funnily enough, even this did fix
the problem, I guess it being set at all was enough :P

I'll send a v2, with this and the one you mentioned updated


> [0] https://www.iana.org/assignments/media-types/application/octet-stream
> [1] https://www.iana.org/assignments/media-types/media-types.xhtml
> 
>>               .header(
>>                   "x-amz-metadata-directive",
>>                   HeaderValue::from_str("REPLACE")?,
>