Struct ProviderUnavailable 

pub struct ProviderUnavailable(pub Error);

A DB-backed auth provider (e.g. DbApiKeyAuthProvider) could not reach its key store — distinguishes a store outage from a rejected credential all the way out to the HTTP/gRPC response.

Wraps the underlying anyhow::Error rather than replacing it: callers that only need to log or propagate the error keep using it as an anyhow::Error (via ?/From), while MultiAuthProvider, auth_middleware, and the gRPC AuthService downcast (anyhow::Error::downcast_ref) to detect this specific kind and map it to a retryable status (503 / Status::unavailable) instead of the blanket “invalid credential” response every other error gets.

Per rust/CLAUDE.md’s anyhow-vs-thiserror rule, the retryable/terminal distinction is modeled as an explicit type rather than an ad-hoc string — that’s the part of the rule this satisfies. What it doesn’t satisfy: callers still reach that type via downcast_ref instead of matching on it directly, because AuthProvider::validate_request returns anyhow::Result and this plan chose not to change that trait’s public return type. Treat this as a deliberate, scoped exception rather than a full application of the rule.

Tuple Fields

0: Error

Trait Implementations

impl Debug for ProviderUnavailable

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Display for ProviderUnavailable

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Error for ProviderUnavailable

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.