option

Documentation

Overview

Package option contains options for Google API clients.

Index

• type ClientCertSource
• type ClientOption
  • func ImpersonateCredentials(target string, delegates ...string) ClientOption
  • func WithAPIKey(apiKey string) ClientOption
  • func WithAudiences(audience ...string) ClientOption
  • func WithClientCertSource(s ClientCertSource) ClientOption
  • func WithCredentials(creds *google.Credentials) ClientOption
  • func WithCredentialsFile(filename string) ClientOption
  • func WithCredentialsJSON(p []byte) ClientOption
  • func WithEndpoint(url string) ClientOption
  • func WithGRPCConn(conn *grpc.ClientConn) ClientOption
  • func WithGRPCConnectionPool(size int) ClientOption
  • func WithGRPCDialOption(opt grpc.DialOption) ClientOption
  • func WithHTTPClient(client *http.Client) ClientOption
  • func WithQuotaProject(quotaProject string) ClientOption
  • func WithRequestReason(requestReason string) ClientOption
  • func WithScopes(scope ...string) ClientOption
  • func WithServiceAccountFile(filename string) ClientOption
  • func WithTelemetryDisabled() ClientOption
  • func WithTokenSource(s oauth2.TokenSource) ClientOption
  • func WithUserAgent(ua string) ClientOption
  • func WithoutAuthentication() ClientOption

Types

type ClientCertSource

type ClientCertSource = func(*tls.CertificateRequestInfo) (*tls.Certificate, error)

ClientCertSource is a function that returns a TLS client certificate to be used when opening TLS connections.

It follows the same semantics as crypto/tls.Config.GetClientCertificate.

This is an EXPERIMENTAL API and may be changed or removed in the future.

type ClientOption

type ClientOption interface {
	Apply(*internal.DialSettings)
}

A ClientOption is an option for a Google API client.

func ImpersonateCredentials

func ImpersonateCredentials(target string, delegates ...string) ClientOption

ImpersonateCredentials returns a ClientOption that will impersonate the target service account.

In order to impersonate the target service account the base service account must have the Service Account Token Creator role, roles/iam.serviceAccountTokenCreator, on the target service account. See https://cloud.google.com/iam/docs/understanding-service-accounts.

Optionally, delegates can be used during impersonation if the base service account lacks the token creator role on the target. When using delegates, each service account must be granted roles/iam.serviceAccountTokenCreator on the next service account in the chain.

For example, if a base service account of SA1 is trying to impersonate target service account SA2 while using delegate service accounts DSA1 and DSA2, the following must be true:

1. Base service account SA1 has roles/iam.serviceAccountTokenCreator on DSA1.
2. DSA1 has roles/iam.serviceAccountTokenCreator on DSA2.
3. DSA2 has roles/iam.serviceAccountTokenCreator on target SA2.

The resulting impersonated credential will either have the default scopes of the client being instantiating or the scopes from WithScopes if provided. Scopes are required for creating impersonated credentials, so if this option is used while not using a NewClient/NewService function, WithScopes must also be explicitly passed in as well.

If the base credential is an authorized user and not a service account, or if the option WithQuotaProject is set, the target service account must have a role that grants the serviceusage.services.use permission such as roles/serviceusage.serviceUsageConsumer.

This is an EXPERIMENTAL API and may be changed or removed in the future.

func WithAPIKey

func WithAPIKey(apiKey string) ClientOption

WithAPIKey returns a ClientOption that specifies an API key to be used as the basis for authentication.

API Keys can only be used for JSON-over-HTTP APIs, including those under the import path google.golang.org/api/....

func WithAudiences

func WithAudiences(audience ...string) ClientOption

WithAudiences returns a ClientOption that specifies an audience to be used as the audience field ("aud") for the JWT token authentication.

func WithClientCertSource

func WithClientCertSource(s ClientCertSource) ClientOption

WithClientCertSource returns a ClientOption that specifies a callback function for obtaining a TLS client certificate.

This option is used for supporting mTLS authentication, where the server validates the client certifcate when establishing a connection.

The callback function will be invoked whenever the server requests a certificate from the client. Implementations of the callback function should try to ensure that a valid certificate can be repeatedly returned on demand for the entire life cycle of the transport client. If a nil Certificate is returned (i.e. no Certificate can be obtained), an error should be returned.

This is an EXPERIMENTAL API and may be changed or removed in the future.

func WithCredentials

func WithCredentials(creds *google.Credentials) ClientOption

WithCredentials returns a ClientOption that authenticates API calls.

func WithCredentialsFile

func WithCredentialsFile(filename string) ClientOption

WithCredentialsFile returns a ClientOption that authenticates API calls with the given service account or refresh token JSON credentials file.

func WithCredentialsJSON

func WithCredentialsJSON(p []byte) ClientOption

WithCredentialsJSON returns a ClientOption that authenticates API calls with the given service account or refresh token JSON credentials.

func WithEndpoint

func WithEndpoint(url string) ClientOption

WithEndpoint returns a ClientOption that overrides the default endpoint to be used for a service.

func WithGRPCConn

func WithGRPCConn(conn *grpc.ClientConn) ClientOption

WithGRPCConn returns a ClientOption that specifies the gRPC client connection to use as the basis of communications. This option may only be used with services that support gRPC as their communication transport. When used, the WithGRPCConn option takes precedent over all other supplied options.

func WithGRPCConnectionPool

func WithGRPCConnectionPool(size int) ClientOption

WithGRPCConnectionPool returns a ClientOption that creates a pool of gRPC connections that requests will be balanced between.

This is an EXPERIMENTAL API and may be changed or removed in the future.

func WithGRPCDialOption

func WithGRPCDialOption(opt grpc.DialOption) ClientOption

WithGRPCDialOption returns a ClientOption that appends a new grpc.DialOption to an underlying gRPC dial. It does not work with WithGRPCConn.

func WithHTTPClient

func WithHTTPClient(client *http.Client) ClientOption

WithHTTPClient returns a ClientOption that specifies the HTTP client to use as the basis of communications. This option may only be used with services that support HTTP as their communication transport. When used, the WithHTTPClient option takes precedent over all other supplied options.

func WithQuotaProject

func WithQuotaProject(quotaProject string) ClientOption

WithQuotaProject returns a ClientOption that specifies the project used for quota and billing purposes.

For more information please read: https://cloud.google.com/apis/docs/system-parameters

func WithRequestReason

func WithRequestReason(requestReason string) ClientOption

WithRequestReason returns a ClientOption that specifies a reason for making the request, which is intended to be recorded in audit logging. An example reason would be a support-case ticket number.

For more information please read: https://cloud.google.com/apis/docs/system-parameters

func WithScopes

func WithScopes(scope ...string) ClientOption

WithScopes returns a ClientOption that overrides the default OAuth2 scopes to be used for a service.

func WithServiceAccountFile

func WithServiceAccountFile(filename string) ClientOption

WithServiceAccountFile returns a ClientOption that uses a Google service account credentials file to authenticate.

Deprecated: Use WithCredentialsFile instead.

func WithTelemetryDisabled

func WithTelemetryDisabled() ClientOption

WithTelemetryDisabled returns a ClientOption that disables default telemetry (OpenCensus) settings on gRPC and HTTP clients. An example reason would be to bind custom telemetry that overrides the defaults.

func WithTokenSource

func WithTokenSource(s oauth2.TokenSource) ClientOption

WithTokenSource returns a ClientOption that specifies an OAuth2 token source to be used as the basis for authentication.

func WithUserAgent

func WithUserAgent(ua string) ClientOption

WithUserAgent returns a ClientOption that sets the User-Agent.

func WithoutAuthentication

func WithoutAuthentication() ClientOption

WithoutAuthentication returns a ClientOption that specifies that no authentication should be used. It is suitable only for testing and for accessing public resources, like public Google Cloud Storage buckets. It is an error to provide both WithoutAuthentication and any of WithAPIKey, WithTokenSource, WithCredentialsFile or WithServiceAccountFile.