Components

    Dapr uses a modular design where functionality is delivered as a component. Each component has an interface definition. All of the components are pluggable so that you can swap out one component with the same interface for another. The components contrib repo is where you can contribute implementations for the component interfaces and extends Dapr’s capabilities.

    A building block can use any combination of components. For example the building block and the state management building block both use . As another example, the Pub/Sub building block uses .

    You can get a list of current components available in the current hosting environment using the CLI command.

    State store components are data stores (databases, files, memory) that store key-value pairs as part of the state management building block.

    Service discovery

    Service discovery components are used with the service invocation building block to integrate with the hosting environment to provide service-to-service discovery. For example, the Kubernetes service discovery component integrates with the Kubernetes DNS service and self hosted uses mDNS.

    Dapr allows custom middleware to be plugged into the request processing pipeline. Middleware can perform additional actions on a request, such as authentication, encryption and message transformation before the request is routed to the user code, or before the request is returned to the client. The middleware components are used with the building block.

    Pub/sub brokers

    External resources can connect to Dapr in order to trigger a service or be called from a service as part of the building block.

    Secret stores

    In Dapr, a is any piece of private information that you want to guard against unwanted users. Secrets stores are used to store secrets that can be retrieved and used in services.