client_factory_component.hpp

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#pragma once
 
/// @file userver/ugrpc/client/client_factory_component.hpp
/// @brief @copybrief ugrpc::client::ClientFactoryComponent
 
#include <userver/components/component_base.hpp>
#include <userver/middlewares/runner.hpp>
 
#include <userver/ugrpc/client/client_factory.hpp>
#include <userver/ugrpc/client/middlewares/base.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace ugrpc::client {
 
namespace impl {
 
/// @brief The interface for a `ClientFactoryComponent` component. So, `ClientFactoryComponent` runs with middlewares.
using MiddlewareRunnerComponentBase = USERVER_NAMESPACE::middlewares::RunnerComponentBase<MiddlewareBase, ClientInfo>;
 
}  // namespace impl
 
// clang-format off
 
/// @ingroup userver_components
///
/// @brief Provides a ClientFactory in the component system
///
/// Multiple ClientFactoryComponent instances may be created if different
/// parameters are required for different clients.
///
/// Requires ugrpc::client::CommonComponent.
///
/// ## Authentication
/// Authentication is controlled by `auth-type` static config field.
/// Possible values:
/// - `insecure` (`InsecureChannelCredentials` - default)
/// - `ssl` (`SslCredentials`)
///
/// Default (system) authentication keys are used regardless of the chosen
/// auth-type.
///
/// ## Service config
/// As per https://github.com/grpc/grpc/blob/master/doc/service_config.md
/// service config should be distributed via the name resolution process.
/// We allow setting default service_config: pass desired JSON literal
/// to `default-service-config` parameter
///
/// ## Static options:
/// The default component name for static config is `"grpc-client-factory"`.
///
/// Name | Description | Default value
/// ---- | ----------- | -------------
/// auth-type | authentication method, see @ref grpc_ssl_authentication "Authentication" | -
/// ssl-credentials-options | TLS/SSL options, see @ref grpc_ssl_authentication "Authentication" | -
/// retry-config | retry configuration for outgoing RPCs | {}
/// channel-args | a map of channel arguments, see gRPC Core docs | {}
/// default-service-config | default service config, see above | -
/// channel-count | Number of underlying grpc::Channel objects | 1
/// middlewares | middlewares names to use | -
/// disable-user-pipeline-middlewares | a flag to disable groups::User middlewares from pipeline | false
/// disable-all-pipeline-middlewares | a flag to disable all middlewares from the pipeline | false
///
/// @see https://grpc.github.io/grpc/core/group__grpc__arg__keys.html
 
// clang-format on
 
class ClientFactoryComponent final : public impl::MiddlewareRunnerComponentBase {
public:
    /// @ingroup userver_component_names
    /// @brief The default name of ugrpc::client::middlewares::log::Component
    static constexpr std::string_view kName = "grpc-client-factory";
 
    ClientFactoryComponent(const components::ComponentConfig& config, const components::ComponentContext& context);
 
    ClientFactory& GetFactory();
 
    static yaml_config::Schema GetStaticConfigSchema();
 
private:
    std::optional<ClientFactory> factory_;
};
 
}  // namespace ugrpc::client
 
template <>
inline constexpr bool components::kHasValidate<ugrpc::client::ClientFactoryComponent> = true;
 
USERVER_NAMESPACE_END