Service invocation on Dapr Docs

Service invocation overview

Mon, 01 Jan 0001 00:00:00 +0000

Using service invocation, your application can reliably and securely communicate with other applications using the standard gRPC or HTTP protocols.

In many microservice-based applications, multiple services need the ability to communicate with one another. This inter-service communication requires that application developers handle problems like:

Service discovery. How do I discover my different services?
Standardizing API calls between services. How do I invoke methods between services?
Secure inter-service communication. How do I call other services securely with encryption and apply access control on the methods?
Mitigating request timeouts or failures. How do I handle retries and transient errors?
Implementing observability and tracing. How do I use tracing to see a call graph with metrics to diagnose issues in production?

Service invocation API

Dapr addresses these challenges by providing a service invocation API that acts similar to a reverse proxy with built-in service discovery, while leveraging built-in distributed tracing, metrics, error handling, encryption and more.

How-To: Invoke services using HTTP

Mon, 01 Jan 0001 00:00:00 +0000

This article demonstrates how to deploy services each with an unique application ID for other services to discover and call endpoints on them using service invocation over HTTP.

Note

If you haven’t already, try out the service invocation quickstart for a quick walk-through on how to use the service invocation API.

Choose an ID for your service

Dapr allows you to assign a global, unique ID for your app. This ID encapsulates the state for your application, regardless of the number of instances it may have.

How-To: Invoke services using gRPC

Mon, 01 Jan 0001 00:00:00 +0000

This article describe how to use Dapr to connect services using gRPC.

By using Dapr’s gRPC proxying capability, you can use your existing proto-based gRPC services and have the traffic go through the Dapr sidecar. Doing so yields the following Dapr service invocation benefits to developers:

Mutual authentication
Tracing
Metrics
Access lists
Network level resiliency
API token based authentication

Dapr allows proxying all kinds of gRPC invocations, including unary and stream-based ones.

How-To: Invoke Non-Dapr Endpoints using HTTP

Mon, 01 Jan 0001 00:00:00 +0000

This article demonstrates how to call a non-Dapr endpoint using Dapr over HTTP.

Using Dapr’s service invocation API, you can communicate with endpoints that either use or do not use Dapr. Using Dapr to call endpoints that do not use Dapr not only provides a consistent API, but also the following Dapr service invocation benefits:

Ability to apply resiliency policies
Call observability with tracing & metrics
Security access control through scoping
Ability to utilize middleware pipeline components
Service discovery
Authentication through the use of headers

HTTP service invocation to external services or non-Dapr endpoints

Sometimes you need to call a non-Dapr HTTP endpoint. For example:

How to: Service invocation across namespaces

Mon, 01 Jan 0001 00:00:00 +0000

In this article, you’ll learn how you can call between services deployed to different namespaces. By default, service invocation supports invoking services within the same namespace by simply referencing the app ID (nodeapp):

localhost:3500/v1.0/invoke/nodeapp/method/neworder

Service invocation also supports calls across namespaces. On all supported hosting platforms, Dapr app IDs conform to a valid FQDN format that includes the target namespace. You can specify both:

The app ID (nodeapp), and
The namespace the app runs in (production).

Example 1