### Running gRPC Server

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Command to start the gRPC server application using Gradle. This server exposes the 'HelloService'.

```Shell
./gradlew :grpc-server:bootRun
```

--------------------------------

### Running Spring Cloud Gateway

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Command to start the Spring Cloud Gateway application using Gradle. This gateway routes gRPC requests.

```Shell
./gradlew :grpc-simple-gateway:bootRun
```

--------------------------------

### Running gRPC Client

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Command to start the gRPC client application using Gradle. This client sends requests to the gRPC service via the gateway.

```Shell
./gradlew :grpc-client:bootRun
```

--------------------------------

### Spring Cloud Gateway Route for gRPC Traffic

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Example route configuration for Spring Cloud Gateway to redirect gRPC traffic. It matches paths starting with 'grpc', forwards to a specified URI, and adds a custom response header.

```YAML
spring:
  cloud:
    gateway:
      routes:
        - id: grpc
          uri: https://localhost:6565
          predicates:
            - Path=/grpc/**
          filters:
            - AddResponseHeader=X-Request-header, header-value
```

--------------------------------

### gRPC Gateway Response Example

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Shows the expected HTTP response from the gRPC JSON gateway after processing a JSON request, including the updated Content-Type header and the transformed payload.

```bash
< HTTP/2 200
< content-type: application/json
< content-length: 34
< 
* Connection #0 to host localhost left intact
{"greeting":"Hello, Duff McKagan"}
```

--------------------------------

### Sending JSON Request via cURL

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Example of sending a POST request with a JSON payload to the gRPC JSON gateway using cURL, demonstrating the interaction with the custom filter.

```bash
curl -XPOST 'https://localhost:8091/json/hello' -d '{"firstName":"Duff","lastName":"McKagan"}' -k -H"Content-Type: application/json" -v
```

--------------------------------

### Spring Cloud Gateway Route for All Traffic

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

A simplified route configuration for Spring Cloud Gateway that forwards all incoming traffic to the gRPC server and adds a response header. This is used in the end-to-end example.

```YAML
      routes:
        - id: grpc
          uri: https://localhost:6565
          predicates:
            - Path=/**
          filters:
            - AddResponseHeader=X-Request-header, header-value
```

--------------------------------

### Running the gRPC Gateway

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Instructions on how to build and run the Spring Cloud Gateway application with the gRPC integration using Gradle.

```shell
./gradlew :grpc-json-gateway:bootRun
```

--------------------------------

### Import JKS to PKCS12 Keystore

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/grpc-server/README.md

Imports an existing JKS keystore ('keystore.jks') into a PKCS12 keystore ('keystore.p12').

```shell
keytool -importkeystore -srckeystore keystore.jks -destkeystore keystore.p12 -deststoretype pkcs12
```

--------------------------------

### gRPC Protocol Buffer Definition

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Defines a simple gRPC service 'HelloService' with a 'hello' RPC method. It uses Protocol Buffers for message serialization, defining 'HelloRequest' and 'HelloResponse' messages.

```Protobuf
syntax = "proto3";

message HelloRequest {
  string firstName = 1;
  string lastName = 2;
}

message HelloResponse {
  string greeting = 1;
}

service HelloService {
  rpc hello(HelloRequest) returns (HelloResponse);
}
```

--------------------------------

### Enable HTTP/2 and SSL in Spring Cloud Gateway

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

Configuration to enable HTTP/2 and SSL for gRPC communication in Spring Cloud Gateway. Requires a keystore file for secure connections.

```YAML
server:
  http2:
    enabled: true
  ssl:
    key-store-type: PKCS12
    key-store: classpath:keystore.p12
    key-store-password: password
    key-password: password
    enabled: true
```

--------------------------------

### Generate RSA Keypair (JKS)

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/grpc-server/README.md

Generates a new RSA key pair with a 2048-bit key size, stored in a JKS keystore file named 'keystore.jks'. The validity period is set to 3650 days.

```shell
keytool -genkeypair -keyalg RSA -keysize 2048 -keystore keystore.jks -validity 3650
```

--------------------------------

### Generate RSA Keypair (PKCS12)

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/grpc-server/README.md

Generates a new RSA key pair with a 2048-bit key size, stored in a PKCS12 keystore file named 'keystore.p12'. The validity period is set to 3650 days.

```shell
keytool -genkeypair -keyalg RSA -keysize 2048 -storetype PKCS12 -keystore keystore.p12 -validity 3650
```

--------------------------------

### Custom JSON to gRPC Filter

Source: https://github.com/albertoimpl/spring-cloud-gateway-grpc/blob/main/README.adoc

A custom Spring Cloud Gateway filter that deserializes a JSON request, creates a gRPC channel, sends a message to a gRPC server, and serializes the gRPC response back to JSON.

```java
static class GRPCResponseDecorator extends ServerHttpResponseDecorator {

  @Override
  public Mono<Void> writeWith(Publisher<?extends DataBuffer> body) {
    exchange.getResponse().getHeaders().set("Content-Type", "application/json");

    URI requestURI = exchange.getRequest().getURI();
    ManagedChannel channel = createSecuredChannel(requestURI.getHost(), 6565);

    return getDelegate().writeWith(deserializeJSONRequest()
            .map(jsonRequest -> {
                String firstName = jsonRequest.getFirstName();
                String lastName = jsonRequest.getLastName();
                return HelloServiceGrpc.newBlockingStub(channel)
                        .hello(HelloRequest.newBuilder()
                                .setFirstName(firstName)
                                .setLastName(lastName)
                                .build());
            })
            .map(this::serialiseJSONResponse)
            .map(wrapGRPCResponse())
            .cast(DataBuffer.class)
            .last());
  }
}
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.