Re: [PATCH proxmox-backup v2] s3-client: fix Content-Type for put and copy object requests

[Christian Ebner <c.ebner@proxmox.com>]

On 3/16/26 3:19 PM, Hannes Laimer wrote:
> Use the IANA registered `application/octet-stream` content type instead
> of the non-standard `binary/octet` value in put_object.
> 
> Also set Content-Type explicitly in copy_object requests, since some S3
> providers drop all source metadata, including Content-Type, when using
> x-amz-metadata-directive REPLACE unless it is explicitly provided. This
> caused s3_refresh to fail with "missing header 'content-type'" on such
> providers when fetching objects moved via copy_object.
> 
> Setting it unconditionally is safe, since put_object already does the
> same.
> 
> Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>

Only one small nit: The header value "application/octet-stream" could 
have been defined as common constant.

Tested by syncing new contents from a local datastore to an s3 datastore 
backed by Ceph RGW and inspecting the content-type header value in the 
ceph client logs. Further, moved a group with patches [0] applied again 
checking the content-type header in the Ceph logs, performed a 
successful s3-refresh and verification job on the group.

[0] 
https://lore.proxmox.com/pbs-devel/c883656f-d89c-4e9d-97ab-3a47ee966200@proxmox.com/T/#t

Reviewed-by: Christian Ebner <c.ebner@proxmox.com>
Tested-by: Christian Ebner <c.ebner@proxmox.com>