feat: support multi-tenant azure deployments in the remote client

This forwards an x-azure-tenant-id header to the remote server when
supplied in storage_options. This makes it possible to have a server
deployment that spans multiple Azure AD tenants.

rust/lancedb/src/connection.rs

@@ -921,8 +921,15 @@ pub struct ConnectBuilder {
 }
 
 #[cfg(feature = "remote")]
-const ENV_VARS_TO_STORAGE_OPTS: [(&str, &str); 1] =
-    [("AZURE_STORAGE_ACCOUNT_NAME", "azure_storage_account_name")];
+const ENV_VARS_TO_STORAGE_OPTS: [(&str, &str); 4] = [
+    ("AZURE_STORAGE_ACCOUNT_NAME", "azure_storage_account_name"),
+    ("AZURE_TENANT_ID", "azure_tenant_id"),
+    ("AZURE_CLIENT_ID", "azure_client_id"),
+    (
+        "AZURE_FEDERATED_TOKEN_FILE",
+        "azure_federated_token_file",
+    ),
+];
 
 impl ConnectBuilder {
     /// Create a new [`ConnectOptions`] with the given database URI.

rust/lancedb/src/remote/client.rs

@@ -438,21 +438,26 @@ impl<S: HttpSend> RestfulLanceDbClient<S> {
             );
         }
 
-        if let Some(v) = options.0.get("account_name") {
-            headers.insert(
-                HeaderName::from_static("x-azure-storage-account-name"),
-                HeaderValue::from_str(v).map_err(|_| Error::InvalidInput {
-                    message: format!("non-ascii storage account name '{}' provided", db_name),
-                })?,
-            );
-        }
-        if let Some(v) = options.0.get("azure_storage_account_name") {
-            headers.insert(
-                HeaderName::from_static("x-azure-storage-account-name"),
-                HeaderValue::from_str(v).map_err(|_| Error::InvalidInput {
-                    message: format!("non-ascii storage account name '{}' provided", db_name),
-                })?,
-            );
+        // Map storage options to HTTP headers for Azure configuration.
+        const OPTION_TO_HEADER: &[(&str, &str)] = &[
+            ("account_name", "x-azure-storage-account-name"),
+            ("azure_storage_account_name", "x-azure-storage-account-name"),
+            ("azure_tenant_id", "x-azure-tenant-id"),
+            ("azure_client_id", "x-azure-client-id"),
+            (
+                "azure_federated_token_file",
+                "x-azure-federated-token-file",
+            ),
+        ];
+        for (opt_key, header_name) in OPTION_TO_HEADER {
+            if let Some(v) = options.get(opt_key) {
+                headers.insert(
+                    HeaderName::from_static(header_name),
+                    HeaderValue::from_str(v).map_err(|_| Error::InvalidInput {
+                        message: format!("non-ascii value for '{}' provided", opt_key),
+                    })?,
+                );
+            }
         }
 
         for (key, value) in &config.extra_headers {

rust/lancedb/src/remote/db.rs

@@ -792,11 +792,21 @@ impl RemoteOptions {
     pub fn new(options: HashMap<String, String>) -> Self {
         Self(options)
     }
+
+    pub fn get(&self, key: &str) -> Option<&String> {
+        self.0.get(key)
+    }
 }
 
 impl From<StorageOptions> for RemoteOptions {
     fn from(options: StorageOptions) -> Self {
-        let supported_opts = vec!["account_name", "azure_storage_account_name"];
+        let supported_opts = vec![
+            "account_name",
+            "azure_storage_account_name",
+            "azure_tenant_id",
+            "azure_client_id",
+            "azure_federated_token_file",
+        ];
         let mut filtered = HashMap::new();
         for opt in supported_opts {
             if let Some(v) = options.0.get(opt) {