Azure API Management - Deploy gRPC API on Azure API management using self hosted gateway

#api #grpc #apimanagement #selfhostegateway

This is a complete guide with steps by step process to deploy the gRPC and how to use Azure API Management to import the gRPC API.
It cover step‑by‑step guide to deploying a gRPC API on Azure API Management (APIM), grounded in the Microsoft documentation and a real-world deployment workflow.

NOTE: This post is published already in GITHUB here. https://github.com/shailugit/apimGrpc/blob/main/README.md

The API Management can expose gRPC services, but with important constraints:

APIM supports gRPC by importing a .proto file and forwarding calls to a gRPC backend.
gRPC requires HTTP/2 end‑to‑end.
gRPC APIs are supported in Self-hosted gateway and not supported in APIM v2 tiers.
You can't use the test console to test gRPC

The major steps claissfied in two major steps

Creating a gRPC server
Calling the gPRC application using APIM

1. Creating gRPC Application

Typical backend deployment steps include the following

Create a .NET gRPC server application
Create a .NET gRPC client application
Test the setup locally
Publish the .NET gRPC server to Azure WebApp and verify the service works directly over HTTPS

Step-1
As a first step we will be building a .NET gRPC server application.
You can skip this step in case you already have gRPC server application.
If you would like to view .NET Core sample used for this sample project, please visit here.

Step-2
As a second step we will be building a .NET gRPC client application. You can skip this step in case you already have gRPC client.
If you would like to view .NET Core client used for this sample project, please visit the below here.

Step-3
Once your client and server code is ready here are the steps to Test your application locally

Step-4
Deploy the server to Azure WebApp
To understand how-to deploy a .NET 6 gRPC app on App Service, please visit here.
Please make sure to enable HTTP version, Enable HTTP 2.0 Proxy and add HTTP20_ONLY_PORT application setting as gRPC only work using http2.0 as shown below

2. Calling gRPC from APIM

Typical API deployment steps include the following

Deploy the self hosted gateway on Azure API management.
Import the gRPC API in API Management
Update the .NET gRPC client application to test using API management.
Since gRPC requires HTTP/2 for inbound and outbound traffic make sure that you enabled HTTP/2 protocol for client traffic.
Go to API Management(left side blade) Settings → Protocols & Ciphers
Enable HTTP/2

Step-1
Deploy the self hosted gateway on Azure API management as explianed here

Step-2
Import the gRPC API in API Management and enable the http2 in API management as shown below

Open your APIM instance in Azure Portal.
Go to APIs > Under Define a new API, select gRPC.
Upload your .proto file.
Enter your gRPC server URL (must be HTTPS + HTTP/2).
Select the gateway you want to expose it on.
Click Create.
API will Parse the .proto file and create operations for each RPC method and Map them to the backend service