[pbs-devel] [RFC proxmox-backup 38/39] datastore: get and set owner for S3 store backend

[Christian Ebner]

Read or write the ownership information from/to the corresponding
object in the S3 object store. Keep that information available if
the bucket is reused as datastore.

Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
---
 pbs-datastore/src/datastore.rs | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/pbs-datastore/src/datastore.rs b/pbs-datastore/src/datastore.rs
index 19d4ca02c..9c8b7de03 100644
--- a/pbs-datastore/src/datastore.rs
+++ b/pbs-datastore/src/datastore.rs
@@ -8,7 +8,7 @@ use std::time::{Duration, SystemTime};
 
 use anyhow::{bail, format_err, Context, Error};
 use nix::unistd::{unlinkat, UnlinkatFlags};
-use pbs_s3_client::{S3Client, S3ClientOptions};
+use pbs_s3_client::{PutObjectResponse, S3Client, S3ClientOptions};
 use pbs_tools::lru_cache::LruCache;
 use tracing::{info, warn};
 
@@ -840,6 +840,22 @@ impl DataStore {
         backup_group: &pbs_api_types::BackupGroup,
     ) -> Result<Authid, Error> {
         let full_path = self.owner_path(ns, backup_group);
+
+        if let DatastoreBackend::S3(s3_client) = self.backend()? {
+            let object_key = full_path
+                .to_str()
+                .ok_or_else(|| format_err!("unexpected owner path"))?;
+            let response =
+                proxmox_async::runtime::block_on(s3_client.get_object(object_key.into()))?
+                    .ok_or_else(|| format_err!("fetching owner failed"))?;
+            let content =
+                proxmox_async::runtime::block_on(hyper::body::HttpBody::collect(response.content))?;
+            let owner = String::from_utf8(content.to_bytes().trim_ascii_end().to_vec())?;
+            return owner
+                .parse()
+                .map_err(|err| format_err!("parsing owner for {backup_group} failed: {err}"));
+        }
+
         let owner = proxmox_sys::fs::file_read_firstline(full_path)?;
         owner
             .trim_end() // remove trailing newline
@@ -868,6 +884,22 @@ impl DataStore {
     ) -> Result<(), Error> {
         let path = self.owner_path(ns, backup_group);
 
+        if let DatastoreBackend::S3(s3_client) = self.backend()? {
+            let object_key = path
+                .to_str()
+                .ok_or_else(|| format_err!("unexpected owner path"))?;
+            let data = hyper::body::Body::from(format!("{auth_id}\n"));
+            let response =
+                proxmox_async::runtime::block_on(s3_client.put_object(object_key.into(), data))?;
+            match response {
+                PutObjectResponse::NeedsRetry => bail!("failed to set owner, needs retry"),
+                PutObjectResponse::PreconditionFailed => {
+                    bail!("failed to set owner, precondition failed")
+                }
+                PutObjectResponse::Success(_) => return Ok(()),
+            }
+        }
+
         let mut open_options = std::fs::OpenOptions::new();
         open_options.write(true);
 
-- 
2.39.5