Microservices

A direct HTTP call between two Kubernetes services seems simple. The caller needs a hostname, a timeout, and sufficient error handling to survive a disappearing pod. Soon it also needs retries, tracing, metrics, transport security, and an answer to which failures are safe to retry. Repeating that work in every service and language is where simple calls become distributed-systems plumbing. Dapr service invocation moves much of that plumbing into the sidecars. The caller sends a standard HTTP or gRPC request to its local Dapr endpoint and identifies the destination by app ID. Dapr discovers a healthy destination instance, preserves tracing context, communicates between sidecars using mTLS on Kubernetes, and forwards the request to the destination application. ...

Dapr on Kubernetes and AKS Dapr gives applications a consistent set of APIs for common distributed-systems concerns while leaving the backing infrastructure replaceable. This series starts with the mental model, builds a fast local development loop, moves the same workload to Azure Kubernetes Service, and then works through the building blocks and production concerns. The series is written for developers and platform engineers who already know the basics of Kubernetes but are new to Dapr. Each post stands on its own; reading in order gives you the smoothest path from first principles to production. ...

Every distributed application gathers various plumbing components. One service requires retries and timeouts, another needs a message broker client, and a third must store some state, retrieve secrets, or discover other services. Over time, each team ends up with a unique set of client libraries, connection handling methods, telemetry, and failure behaviors. Dapr, the Distributed Application Runtime, provides a uniform API for the underlying infrastructure. Your application communicates with a local Dapr process via HTTP or gRPC. Dapr then interacts with services, the state store, the broker, the secret store, or other components on your application’s behalf. While the application retains control of its business logic, Dapr offers reusable capabilities for building distributed applications. ...