Struct DanubeClientBuilder 

pub struct DanubeClientBuilder { /* private fields */ }

A builder for configuring and creating a DanubeClient instance.

The DanubeClientBuilder struct provides methods for setting various options needed to construct a DanubeClient. This includes configuring the base URI for the Danube service, connection settings.

Fields

• uri: The base URI for the Danube service. This is a required field and specifies the address of the service that the client will connect to. It is essential for constructing the DanubeClient.
• connection_options: Optional connection settings that define how the grpc client connects to the Danube service. These settings can include parameters such as timeouts, retries, and other connection-related configurations.

Implementations

impl DanubeClientBuilder

pub fn service_url(self, url: impl Into<String>) -> Self

Sets the base URI for the Danube service in the builder.

This method configures the base URI that the DanubeClient will use to connect to the Danube service. The base URI is a required parameter for establishing a connection and interacting with the service.

Parameters

• url: The base URI to use for connecting to the Danube service. The URI should include the protocol and address of the Danube service.

pub fn with_tls(self, ca_cert: impl AsRef<Path>) -> Result<Self>

Sets the TLS configuration for the client in the builder.

pub fn with_mtls( self, ca_cert: impl AsRef<Path>, client_cert: impl AsRef<Path>, client_key: impl AsRef<Path>, ) -> Result<Self>

Sets the mutual TLS configuration for the client in the builder.

pub fn with_token(self, token: impl Into<String>) -> Self

Sets the authentication token (JWT) for the client.

Use danube-admin security tokens create to generate a token. Automatically enables TLS. If no TLS config has been set via with_tls() or with_mtls(), a default TLS config using system root certificates is applied.

For tokens that expire, consider with_token_supplier instead, which allows runtime token refresh.

pub fn with_token_supplier( self, supplier: impl Fn() -> String + Send + Sync + 'static, ) -> Self

Sets a dynamic token supplier for the client.

The supplier function is called on every gRPC request to obtain the current token, enabling runtime token refresh without restarting the client. This is useful for:

• File-based tokens: Read from a file that is updated by infrastructure (e.g., K8s projected volumes, sidecar token refreshers)
• Environment-based tokens: Read from an environment variable
• Custom refresh logic: Implement your own token rotation

Automatically enables TLS (same as with_token).

Examples

// Read token from a file on each request
let client = DanubeClient::builder()
    .service_url("https://broker:6650")
    .with_token_supplier(|| {
        std::fs::read_to_string("/var/run/secrets/danube-token")
            .unwrap_or_default()
            .trim()
            .to_string()
    })
    .build()
    .await?;

pub fn with_api_key(self, api_key: impl Into<String>) -> Self

👎Deprecated since 0.11.0:

Use with_token() — Danube now uses JWT tokens instead of API keys

Deprecated: Use with_token() instead. This method treats the input as a JWT token.

pub fn with_internal_broker(self, broker_name: impl Into<String>) -> Self

Sets the internal broker identity for the client in the builder.

pub async fn build(self) -> Result<DanubeClient>

Constructs and returns a DanubeClient instance based on the configuration specified in the builder.

This method finalizes the configuration and creates a new DanubeClient instance. It uses the settings and options that were configured using the DanubeClientBuilder methods.

Returns

• Ok(DanubeClient): A new instance of DanubeClient configured with the specified options.
• Err(e): An error if the configuration is invalid or incomplete.

Trait Implementations

impl Clone for DanubeClientBuilder

fn clone(&self) -> DanubeClientBuilder

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DanubeClientBuilder

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

Formats the value using the given formatter.

impl Default for DanubeClientBuilder

fn default() -> DanubeClientBuilder

Returns the “default value” for a type.