Struct Builder 

pub struct Builder { /* private fields */ }

A builder for constructing Impersonated Service Account Credentials instance.

Example

let impersonated_credential = serde_json::json!({
    "type": "impersonated_service_account",
    "service_account_impersonation_url": "https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/test-principal:generateAccessToken",
    "source_credentials": {
        "type": "authorized_user",
        "client_id": "test-client-id",
        "client_secret": "test-client-secret",
        "refresh_token": "test-refresh-token"
    }
});
let credentials = Builder::new(impersonated_credential).build();

Implementations

impl Builder

pub fn new(impersonated_credential: Value) -> Self

Creates a new builder using impersonated_service_account JSON value.

The impersonated_service_account JSON is typically generated using a gcloud command for application default login.

pub fn from_source_credentials(source_credentials: Credentials) -> Self

Creates a new builder with a source credentials object.

Example

let source_credentials = user_account::Builder::new(json!({ /* add details here */ })).build()?;

let creds = impersonated::Builder::from_source_credentials(source_credentials)
    .with_target_principal("test-principal")
    .build()?;

pub fn with_target_principal<S: Into<String>>(self, target_principal: S) -> Self

Sets the target principal. This is required when using from_source_credentials. Target principal is the email of the service account to impersonate.

Example

let impersonated_credential = json!({ /* add details here */ });

let creds = impersonated::Builder::new(impersonated_credential.into())
    .with_target_principal("test-principal")
    .build();

pub fn with_delegates<I, S>(self, delegates: I) -> Self

where I: IntoIterator<Item = S>, S: Into<String>,

Sets the chain of delegates.

Example

let impersonated_credential = json!({ /* add details here */ });

let creds = impersonated::Builder::new(impersonated_credential.into())
    .with_delegates(["delegate1", "delegate2"])
    .build();

pub fn with_scopes<I, S>(self, scopes: I) -> Self

where I: IntoIterator<Item = S>, S: Into<String>,

Sets the scopes for these credentials. By default https://www.googleapis.com/auth/cloud-platform scope is used.

Example

let impersonated_credential = json!({ /* add details here */ });

let creds = impersonated::Builder::new(impersonated_credential.into())
    .with_scopes(["https://www.googleapis.com/auth/pubsub"])
    .build();

pub fn with_quota_project_id<S: Into<String>>(self, quota_project_id: S) -> Self

Sets the quota project for these credentials.

For some services, you can use an account in one project for authentication and authorization, and charge the usage to a different project. This requires that the target service account has serviceusage.services.use permissions on the quota project.

Any value set here overrides a quota_project_id value from the input impersonated_service_account JSON.

Example

let impersonated_credential = json!({ /* add details here */ });

let creds = impersonated::Builder::new(impersonated_credential.into())
    .with_quota_project_id("my-project")
    .build();

pub fn with_lifetime(self, lifetime: Duration) -> Self

Sets the lifetime for the impersonated credentials.

Example

let impersonated_credential = json!({ /* add details here */ });

let creds = impersonated::Builder::new(impersonated_credential.into())
    .with_lifetime(Duration::from_secs(500))
    .build();

pub fn with_retry_policy<V: Into<RetryPolicyArg>>(self, v: V) -> Self

Configure the retry policy for fetching tokens.

The retry policy controls how to handle retries, and sets limits on the number of attempts or the total time spent retrying.

use gax::retry_policy::{AlwaysRetry, RetryPolicyExt};
let impersonated_credential = json!({ /* add details here */ });
let credentials = Builder::new(impersonated_credential.into())
    .with_retry_policy(AlwaysRetry.with_attempt_limit(3))
    .build();

pub fn with_backoff_policy<V: Into<BackoffPolicyArg>>(self, v: V) -> Self

Configure the retry backoff policy.

The backoff policy controls how long to wait in between retry attempts.

use gax::exponential_backoff::ExponentialBackoff;
let policy = ExponentialBackoff::default();
let impersonated_credential = json!({ /* add details here */ });
let credentials = Builder::new(impersonated_credential.into())
    .with_backoff_policy(policy)
    .build();

pub fn with_retry_throttler<V: Into<RetryThrottlerArg>>(self, v: V) -> Self

Configure the retry throttler.

Advanced applications may want to configure a retry throttler to Address Cascading Failures and when Handling Overload conditions. The authentication library throttles its retry loop, using a policy to control the throttling algorithm. Use this method to fine tune or customize the default retry throttler.

use gax::retry_throttler::AdaptiveThrottler;
let impersonated_credential = json!({ /* add details here */ });
let credentials = Builder::new(impersonated_credential.into())
    .with_retry_throttler(AdaptiveThrottler::default())
    .build();

pub fn build(self) -> Result<Credentials, Error>

Returns a Credentials instance with the configured settings.

Errors

Returns a BuilderError for one of the following cases:

• If the impersonated_service_account provided to Builder::new cannot be successfully deserialized into the expected format. This typically happens if the JSON value is malformed or missing required fields. For more information, on how to generate impersonated_service_account json, consult the relevant section in the application-default credentials guide.
• If the impersonated_service_account provided to Builder::new has a source_credentials of impersonated_service_account type.
• If service_account_impersonation_url is not provided after initializing the builder with Builder::from_source_credentials.