Move remote_storage config related code into dedicated module (#8132)

Moves `RemoteStorageConfig` and related structs and functions into a
dedicated module. Also implements `Serialize` for the config structs
(requested in #8126).

Follow-up of #8126

libs/remote_storage/src/azure_blob.rs

@@ -34,7 +34,7 @@ use utils::backoff;
 
 use crate::metrics::{start_measuring_requests, AttemptOutcome, RequestKind};
 use crate::{
-    error::Cancelled, AzureConfig, ConcurrencyLimiter, Download, DownloadError, Listing,
+    config::AzureConfig, error::Cancelled, ConcurrencyLimiter, Download, DownloadError, Listing,
     ListingMode, RemotePath, RemoteStorage, StorageMetadata, TimeTravelError, TimeoutOrCancel,
 };
 

libs/remote_storage/src/config.rs

@@ -0,0 +1,277 @@
+use std::{fmt::Debug, num::NonZeroUsize, str::FromStr, time::Duration};
+
+use anyhow::bail;
+use aws_sdk_s3::types::StorageClass;
+use camino::Utf8PathBuf;
+
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    DEFAULT_MAX_KEYS_PER_LIST_RESPONSE, DEFAULT_REMOTE_STORAGE_AZURE_CONCURRENCY_LIMIT,
+    DEFAULT_REMOTE_STORAGE_S3_CONCURRENCY_LIMIT,
+};
+
+/// External backup storage configuration, enough for creating a client for that storage.
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
+pub struct RemoteStorageConfig {
+    /// The storage connection configuration.
+    #[serde(flatten)]
+    pub storage: RemoteStorageKind,
+    /// A common timeout enforced for all requests after concurrency limiter permit has been
+    /// acquired.
+    #[serde(
+        with = "humantime_serde",
+        default = "default_timeout",
+        skip_serializing_if = "is_default_timeout"
+    )]
+    pub timeout: Duration,
+}
+
+fn default_timeout() -> Duration {
+    RemoteStorageConfig::DEFAULT_TIMEOUT
+}
+
+fn is_default_timeout(d: &Duration) -> bool {
+    *d == RemoteStorageConfig::DEFAULT_TIMEOUT
+}
+
+/// A kind of a remote storage to connect to, with its connection configuration.
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
+#[serde(untagged)]
+pub enum RemoteStorageKind {
+    /// Storage based on local file system.
+    /// Specify a root folder to place all stored files into.
+    LocalFs { local_path: Utf8PathBuf },
+    /// AWS S3 based storage, storing all files in the S3 bucket
+    /// specified by the config
+    AwsS3(S3Config),
+    /// Azure Blob based storage, storing all files in the container
+    /// specified by the config
+    AzureContainer(AzureConfig),
+}
+
+/// AWS S3 bucket coordinates and access credentials to manage the bucket contents (read and write).
+#[derive(Clone, PartialEq, Eq, Deserialize, Serialize)]
+pub struct S3Config {
+    /// Name of the bucket to connect to.
+    pub bucket_name: String,
+    /// The region where the bucket is located at.
+    pub bucket_region: String,
+    /// A "subfolder" in the bucket, to use the same bucket separately by multiple remote storage users at once.
+    pub prefix_in_bucket: Option<String>,
+    /// A base URL to send S3 requests to.
+    /// By default, the endpoint is derived from a region name, assuming it's
+    /// an AWS S3 region name, erroring on wrong region name.
+    /// Endpoint provides a way to support other S3 flavors and their regions.
+    ///
+    /// Example: `http://127.0.0.1:5000`
+    pub endpoint: Option<String>,
+    /// AWS S3 has various limits on its API calls, we need not to exceed those.
+    /// See [`DEFAULT_REMOTE_STORAGE_S3_CONCURRENCY_LIMIT`] for more details.
+    #[serde(default = "default_remote_storage_s3_concurrency_limit")]
+    pub concurrency_limit: NonZeroUsize,
+    #[serde(default = "default_max_keys_per_list_response")]
+    pub max_keys_per_list_response: Option<i32>,
+    #[serde(
+        deserialize_with = "deserialize_storage_class",
+        serialize_with = "serialize_storage_class",
+        default
+    )]
+    pub upload_storage_class: Option<StorageClass>,
+}
+
+fn default_remote_storage_s3_concurrency_limit() -> NonZeroUsize {
+    DEFAULT_REMOTE_STORAGE_S3_CONCURRENCY_LIMIT
+        .try_into()
+        .unwrap()
+}
+
+fn default_max_keys_per_list_response() -> Option<i32> {
+    DEFAULT_MAX_KEYS_PER_LIST_RESPONSE
+}
+
+impl Debug for S3Config {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("S3Config")
+            .field("bucket_name", &self.bucket_name)
+            .field("bucket_region", &self.bucket_region)
+            .field("prefix_in_bucket", &self.prefix_in_bucket)
+            .field("concurrency_limit", &self.concurrency_limit)
+            .field(
+                "max_keys_per_list_response",
+                &self.max_keys_per_list_response,
+            )
+            .finish()
+    }
+}
+
+/// Azure  bucket coordinates and access credentials to manage the bucket contents (read and write).
+#[derive(Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct AzureConfig {
+    /// Name of the container to connect to.
+    pub container_name: String,
+    /// Name of the storage account the container is inside of
+    pub storage_account: Option<String>,
+    /// The region where the bucket is located at.
+    pub container_region: String,
+    /// A "subfolder" in the container, to use the same container separately by multiple remote storage users at once.
+    pub prefix_in_container: Option<String>,
+    /// Azure has various limits on its API calls, we need not to exceed those.
+    /// See [`DEFAULT_REMOTE_STORAGE_AZURE_CONCURRENCY_LIMIT`] for more details.
+    #[serde(default = "default_remote_storage_azure_concurrency_limit")]
+    pub concurrency_limit: NonZeroUsize,
+    #[serde(default = "default_max_keys_per_list_response")]
+    pub max_keys_per_list_response: Option<i32>,
+}
+
+fn default_remote_storage_azure_concurrency_limit() -> NonZeroUsize {
+    NonZeroUsize::new(DEFAULT_REMOTE_STORAGE_AZURE_CONCURRENCY_LIMIT).unwrap()
+}
+
+impl Debug for AzureConfig {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("AzureConfig")
+            .field("bucket_name", &self.container_name)
+            .field("storage_account", &self.storage_account)
+            .field("bucket_region", &self.container_region)
+            .field("prefix_in_container", &self.prefix_in_container)
+            .field("concurrency_limit", &self.concurrency_limit)
+            .field(
+                "max_keys_per_list_response",
+                &self.max_keys_per_list_response,
+            )
+            .finish()
+    }
+}
+
+fn deserialize_storage_class<'de, D: serde::Deserializer<'de>>(
+    deserializer: D,
+) -> Result<Option<StorageClass>, D::Error> {
+    Option::<String>::deserialize(deserializer).and_then(|s| {
+        if let Some(s) = s {
+            use serde::de::Error;
+            let storage_class = StorageClass::from_str(&s).expect("infallible");
+            #[allow(deprecated)]
+            if matches!(storage_class, StorageClass::Unknown(_)) {
+                return Err(D::Error::custom(format!(
+                    "Specified storage class unknown to SDK: '{s}'. Allowed values: {:?}",
+                    StorageClass::values()
+                )));
+            }
+            Ok(Some(storage_class))
+        } else {
+            Ok(None)
+        }
+    })
+}
+
+fn serialize_storage_class<S: serde::Serializer>(
+    val: &Option<StorageClass>,
+    serializer: S,
+) -> Result<S::Ok, S::Error> {
+    let val = val.as_ref().map(StorageClass::as_str);
+    Option::<&str>::serialize(&val, serializer)
+}
+
+impl RemoteStorageConfig {
+    pub const DEFAULT_TIMEOUT: Duration = std::time::Duration::from_secs(120);
+
+    pub fn from_toml(toml: &toml_edit::Item) -> anyhow::Result<Option<RemoteStorageConfig>> {
+        let document: toml_edit::Document = match toml {
+            toml_edit::Item::Table(toml) => toml.clone().into(),
+            toml_edit::Item::Value(toml_edit::Value::InlineTable(toml)) => {
+                toml.clone().into_table().into()
+            }
+            _ => bail!("toml not a table or inline table"),
+        };
+
+        if document.is_empty() {
+            return Ok(None);
+        }
+
+        Ok(Some(toml_edit::de::from_document(document)?))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn parse(input: &str) -> anyhow::Result<Option<RemoteStorageConfig>> {
+        let toml = input.parse::<toml_edit::Document>().unwrap();
+        RemoteStorageConfig::from_toml(toml.as_item())
+    }
+
+    #[test]
+    fn parse_localfs_config_with_timeout() {
+        let input = "local_path = '.'
+timeout = '5s'";
+
+        let config = parse(input).unwrap().expect("it exists");
+
+        assert_eq!(
+            config,
+            RemoteStorageConfig {
+                storage: RemoteStorageKind::LocalFs {
+                    local_path: Utf8PathBuf::from(".")
+                },
+                timeout: Duration::from_secs(5)
+            }
+        );
+    }
+
+    #[test]
+    fn test_s3_parsing() {
+        let toml = "\
+    bucket_name = 'foo-bar'
+    bucket_region = 'eu-central-1'
+    upload_storage_class = 'INTELLIGENT_TIERING'
+    timeout = '7s'
+    ";
+
+        let config = parse(toml).unwrap().expect("it exists");
+
+        assert_eq!(
+            config,
+            RemoteStorageConfig {
+                storage: RemoteStorageKind::AwsS3(S3Config {
+                    bucket_name: "foo-bar".into(),
+                    bucket_region: "eu-central-1".into(),
+                    prefix_in_bucket: None,
+                    endpoint: None,
+                    concurrency_limit: default_remote_storage_s3_concurrency_limit(),
+                    max_keys_per_list_response: DEFAULT_MAX_KEYS_PER_LIST_RESPONSE,
+                    upload_storage_class: Some(StorageClass::IntelligentTiering),
+                }),
+                timeout: Duration::from_secs(7)
+            }
+        );
+    }
+
+    #[test]
+    fn test_azure_parsing() {
+        let toml = "\
+    container_name = 'foo-bar'
+    container_region = 'westeurope'
+    upload_storage_class = 'INTELLIGENT_TIERING'
+    timeout = '7s'
+    ";
+
+        let config = parse(toml).unwrap().expect("it exists");
+
+        assert_eq!(
+            config,
+            RemoteStorageConfig {
+                storage: RemoteStorageKind::AzureContainer(AzureConfig {
+                    container_name: "foo-bar".into(),
+                    storage_account: None,
+                    container_region: "westeurope".into(),
+                    prefix_in_container: None,
+                    concurrency_limit: default_remote_storage_azure_concurrency_limit(),
+                    max_keys_per_list_response: DEFAULT_MAX_KEYS_PER_LIST_RESPONSE,
+                }),
+                timeout: Duration::from_secs(7)
+            }
+        );
+    }
+}