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

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

[Hannes Laimer]

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>
---
did notice this with RustFS, MinIO did not have that problem

v2, thanks @Chris:
 - use `application/octet-stream`
 - also change to `application/octet-stream` in `put_object`


 proxmox-s3-client/src/client.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/proxmox-s3-client/src/client.rs b/proxmox-s3-client/src/client.rs
index 413b3984..fbffe3e9 100644
--- a/proxmox-s3-client/src/client.rs
+++ b/proxmox-s3-client/src/client.rs
@@ -530,7 +530,7 @@ impl S3Client {
         let mut request = Request::builder()
             .method(Method::PUT)
             .uri(self.build_uri(&object_key, &[])?)
-            .header(header::CONTENT_TYPE, "binary/octet");
+            .header(header::CONTENT_TYPE, "application/octet-stream");
 
         if !replace {
             // Some providers not implement this and fails with error if the header is set,
@@ -660,6 +660,7 @@ 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, "application/octet-stream")
             .header(
                 "x-amz-metadata-directive",
                 HeaderValue::from_str("REPLACE")?,
-- 
2.47.3

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

[Hannes Laimer]

oops, sorry, wrong header. this is for `proxmox`

On 2026-03-16 15:19, 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>
> ---
> did notice this with RustFS, MinIO did not have that problem
> 
> v2, thanks @Chris:
>  - use `application/octet-stream`
>  - also change to `application/octet-stream` in `put_object`
> 
> 
>  proxmox-s3-client/src/client.rs | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/proxmox-s3-client/src/client.rs b/proxmox-s3-client/src/client.rs
> index 413b3984..fbffe3e9 100644
> --- a/proxmox-s3-client/src/client.rs
> +++ b/proxmox-s3-client/src/client.rs
> @@ -530,7 +530,7 @@ impl S3Client {
>          let mut request = Request::builder()
>              .method(Method::PUT)
>              .uri(self.build_uri(&object_key, &[])?)
> -            .header(header::CONTENT_TYPE, "binary/octet");
> +            .header(header::CONTENT_TYPE, "application/octet-stream");
>  
>          if !replace {
>              // Some providers not implement this and fails with error if the header is set,
> @@ -660,6 +660,7 @@ 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, "application/octet-stream")
>              .header(
>                  "x-amz-metadata-directive",
>                  HeaderValue::from_str("REPLACE")?,

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

[Christian Ebner]

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>