Enum Adc 

pub enum Adc {
    Metadata(Metadata),
    User(GcloudUser),
    Static(Static),
}

Application Default Credentials (no private-key signing).

Variants

Metadata(Metadata)

The instance metadata server.

User(GcloudUser)

gcloud user credentials.

Static(Static)

A fixed token.

Implementations

impl Adc

pub fn discover() -> Result<Self>

GOOGLE_APPLICATION_CREDENTIALS (user credentials), then gcloud’s well-known file, then the metadata server (discover_with under MetadataPolicy::Allow).

pub fn discover_with(metadata: MetadataPolicy) -> Result<Self>

Discovery as discover, with the metadata server allowed or forbidden.

pub fn from_access_token(secret: impl Into<String>) -> Result<Self>

A caller-supplied access token, used as is and never refreshed (Adc::Static). An empty or blank token is Error::NoCredentials: it would send unauthenticated requests.

Trait Implementations

impl Debug for Adc

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

Formats the value using the given formatter.

impl TokenProvider for Adc

type Token<'a> = impl Future<Output = Result<AccessToken, Error>> + 'a

Future of token.

fn token(&self) -> Self::Token<'_>

A token valid for at least a minute (an empty secret sends no header).

fn quota_project(&self) -> Option<&str>

The project billed for API quota (user credentials only).