[pbs-devel] [PATCH proxmox-backup v8 04/45] api: datastore: check s3 backend bucket access on datastore create

[Lukas Wagner]

With the two string constants moved:

Reviewed-by: Lukas Wagner <l.wagner at proxmox.com>


On  2025-07-15 14:52, Christian Ebner wrote:
> Check if the configured S3 object store backend can be reached and
> the provided secrets have the permissions to access the bucket.
> 
> Perform the check before creating the chunk store, so it is not left
> behind if the bucket cannot be reached.
> 
> Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
> ---
> changes since version 7:
> - no changes
> 
>  Cargo.toml                   |  2 +-
>  src/api2/config/datastore.rs | 48 ++++++++++++++++++++++++++++++++----
>  2 files changed, 44 insertions(+), 6 deletions(-)
> 
> diff --git a/Cargo.toml b/Cargo.toml
> index c7a77060e..a5954635a 100644
> --- a/Cargo.toml
> +++ b/Cargo.toml
> @@ -77,7 +77,7 @@ proxmox-rest-server = { version = "1", features = [ "templates" ] }
>  proxmox-router = { version = "3.2.2", default-features = false }
>  proxmox-rrd = "1"
>  proxmox-rrd-api-types = "1.0.2"
> -proxmox-s3-client = "1.0.0"
> +proxmox-s3-client = { version = "1.0.0", features = [ "impl" ] }
>  # everything but pbs-config and pbs-client use "api-macro"
>  proxmox-schema = "4"
>  proxmox-section-config = "3"
> diff --git a/src/api2/config/datastore.rs b/src/api2/config/datastore.rs
> index b133be707..0fb822c79 100644
> --- a/src/api2/config/datastore.rs
> +++ b/src/api2/config/datastore.rs
> @@ -1,21 +1,22 @@
>  use std::path::{Path, PathBuf};
>  
>  use ::serde::{Deserialize, Serialize};
> -use anyhow::{bail, Context, Error};
> +use anyhow::{bail, format_err, Context, Error};
>  use hex::FromHex;
>  use serde_json::Value;
>  use tracing::{info, warn};
>  
>  use proxmox_router::{http_bail, Permission, Router, RpcEnvironment, RpcEnvironmentType};
> +use proxmox_s3_client::{S3Client, S3ClientConfig, S3ClientOptions, S3ClientSecretsConfig};
>  use proxmox_schema::{api, param_bail, ApiType};
>  use proxmox_section_config::SectionConfigData;
>  use proxmox_uuid::Uuid;
>  
>  use pbs_api_types::{
> -    Authid, DataStoreConfig, DataStoreConfigUpdater, DatastoreNotify, DatastoreTuning, KeepOptions,
> -    MaintenanceMode, PruneJobConfig, PruneJobOptions, DATASTORE_SCHEMA, PRIV_DATASTORE_ALLOCATE,
> -    PRIV_DATASTORE_AUDIT, PRIV_DATASTORE_MODIFY, PRIV_SYS_MODIFY, PROXMOX_CONFIG_DIGEST_SCHEMA,
> -    UPID_SCHEMA,
> +    Authid, DataStoreConfig, DataStoreConfigUpdater, DatastoreBackendConfig, DatastoreBackendType,
> +    DatastoreNotify, DatastoreTuning, KeepOptions, MaintenanceMode, PruneJobConfig,
> +    PruneJobOptions, DATASTORE_SCHEMA, PRIV_DATASTORE_ALLOCATE, PRIV_DATASTORE_AUDIT,
> +    PRIV_DATASTORE_MODIFY, PRIV_SYS_MODIFY, PROXMOX_CONFIG_DIGEST_SCHEMA, UPID_SCHEMA,
>  };
>  use pbs_config::BackupLockGuard;
>  use pbs_datastore::chunk_store::ChunkStore;
> @@ -116,6 +117,43 @@ pub(crate) fn do_create_datastore(
>              .parse_property_string(datastore.tuning.as_deref().unwrap_or(""))?,
>      )?;
>  
> +    if let Some(ref backend_config) = datastore.backend {
> +        let backend_config: DatastoreBackendConfig = backend_config.parse()?;
> +        match backend_config.ty.unwrap_or_default() {
> +            DatastoreBackendType::Filesystem => (),
> +            DatastoreBackendType::S3 => {
> +                let s3_client_id = backend_config
> +                    .client
> +                    .as_ref()
> +                    .ok_or_else(|| format_err!("missing required client"))?;
> +                let bucket = backend_config
> +                    .bucket
> +                    .clone()
> +                    .ok_or_else(|| format_err!("missing required bucket"))?;
> +                let (config, _config_digest) =
> +                    pbs_config::s3::config().context("failed to get s3 config")?;
> +                let (secrets, _secrets_digest) =
> +                    pbs_config::s3::secrets_config().context("failed to get s3 secrets")?;
> +                let config: S3ClientConfig = config
> +                    .lookup("s3client", s3_client_id)
> +                    .with_context(|| format!("no '{s3_client_id}' in config"))?;
> +                let secrets: S3ClientSecretsConfig = secrets
> +                    .lookup("s3secrets", s3_client_id)
> +                    .with_context(|| format!("no '{s3_client_id}' in secrets"))?;

The "s3client" and "s3secrets" section type strings should be `pub const` where the the config parser is defined.

> +                let options = S3ClientOptions::from_config(
> +                    config,
> +                    secrets,
> +                    bucket,
> +                    datastore.name.to_owned(),
> +                );
> +                let s3_client = S3Client::new(options).context("failed to create s3 client")?;
> +                // Fine to block since this runs in worker task
> +                proxmox_async::runtime::block_on(s3_client.head_bucket())
> +                    .context("failed to access bucket")?;

I wonder whether we should add some kind of retry logic not only here, but also for anywhere else
where we interact with S3. Might of course be easier to implement that right in the s3 client crate.
Also, no need to add this right away, just some idea for future improvements.

> +            }
> +        }
> +    }
> +
>      let unmount_guard = if datastore.backing_device.is_some() {
>          do_mount_device(datastore.clone())?;
>          UnmountGuard::new(Some(path.clone()))

-- 
- Lukas