Struct GoogleAccessToken 

pub struct GoogleAccessToken { /* private fields */ }

A cached source of Google OAuth2 access tokens. See the module docs.

Implementations

impl GoogleAccessToken

pub fn from_env() -> Self

GOOGLE_ACCESS_TOKEN when set; otherwise the metadata server when one answers (Cloud Run, GKE, Compute Engine), else gcloud auth print-access-token. GCE_METADATA_HOST overrides the metadata host.

pub fn fixed(token: impl Into<String>) -> Self

Always this token (it is not refreshed).

pub fn metadata_server(host: impl Into<String>) -> Self

Tokens for the attached service account, from the metadata server at host (normally metadata.google.internal).

pub fn gcloud() -> Self

Tokens from gcloud auth print-access-token.

pub async fn token(&self) -> Result<String, AuthError>

A valid access token, fetching a new one when the cached one is about to expire.

pub async fn invalidate(&self)

Forget the cached token, e.g. after a request was rejected with 401.

pub async fn into_access_token(self) -> Result<AccessToken, AuthError>

An AccessToken that stays valid for as long as it is held.

AccessToken is read synchronously on every connection attempt, and fetching a token is asynchronous, so the token is fetched here once (an error means there are no usable credentials) and then kept fresh by a background task. The task checks every minute and fetches a new token shortly before the current one expires. It stops once every clone of the returned AccessToken is dropped. If a refresh fails, the previous token is kept and the next check retries.

Must be called inside a Tokio runtime.

Trait Implementations

impl Debug for GoogleAccessToken

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

Formats the value using the given formatter.