2.45. gRPC
Expose gRPC endpoints and access external gRPC endpoints.
2.45.1. What’s inside
-
gRPC component, URI syntax:
grpc:host:port/service
Refer to the above link for usage and configuration details.
2.45.2. Maven coordinates
Create a new project with this extension on code.camel.redhat.com
Or add the coordinates to your existing project:
<dependency>
<groupId>org.apache.camel.quarkus</groupId>
<artifactId>camel-quarkus-grpc</artifactId>
</dependency>2.45.3. Usage
2.45.3.1. Protobuf generated code
Camel Quarkus gRPC can generate gRPC service stubs for .proto files. When using Maven, ensure that you have enabled the generate-code goals of the quarkus-maven-plugin in your project build.
<build>
<plugins>
<plugin>
<groupId>io.quarkus</groupId>
<artifactId>quarkus-maven-plugin</artifactId>
<version>${quarkus.platform.version}</version>
<extensions>true</extensions>
<executions>
<execution>
<goals>
<goal>build</goal>
<goal>generate-code</goal>
<goal>generate-code-tests</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
With this configuration, you can put your service and message definitions into the src/main/proto directory and the quarkus-maven-plugin will generate code from your .proto files.
2.45.3.1.1. Scanning proto files with imports
The Protocol Buffers specification provides a way to import proto files. You can control the scope of dependencies to scan by adding configuration property quarkus.camel.grpc.codegen.scan-for-imports property to application.properties. The available options are outlined below.
-
all- Scan all dependencies -
none- Disable dependency scanning. Use only the proto definitions defined insrc/main/protoorsrc/test/proto -
groupId1:artifactId1,groupId2:artifactId2- Scan only the dependencies matching thegroupIdandartifactIdlist
The default value is com.google.protobuf:protobuf-java.
2.45.3.1.2. Scanning proto files from dependencies
If you have proto files shared across multiple dependencies, you can generate gRPC service stubs for them by adding configuration property quarkus.camel.grpc.codegen.scan-for-proto to application.properties.
First add a dependency for the artifact(s) containing proto files to your project. Next, enable proto file dependency scanning.
quarkus.camel.grpc.codegen.scan-for-proto=org.my.groupId1:my-artifact-id-1,org.my.groupId2:my-artifact-id-2It is possible to include / exclude specific proto files from dependency scanning via configuration properties.
The configuration property name suffix is the Maven groupId / artifactId for the dependency to configure includes / excludes on. Paths are relative to the classpath location of the proto files within the dependency. Paths can be an explicit path to a proto file, or as glob patterns to include / exclude multiple files.
quarkus.camel.grpc.codegen.scan-for-proto-includes."<groupId>\:<artifactId>"=foo/**,bar/**,baz/a-proto.proto
quarkus.camel.grpc.codegen.scan-for-proto-excludes."<groupId>\:<artifactId>"=foo/private/**,baz/another-proto.proto
The : character within property keys must be escaped with \.
2.45.3.2. Accessing classpath resources in native mode
The gRPC component has various options where resources are resolved from the classpath:
-
keyCertChainResource -
keyResource -
serviceAccountResource -
trustCertCollectionResource
When using these options in native mode, you must ensure that any such resources are included in the native image.
This can be accomplished by adding the configuration property quarkus.native.resources.includes to application.properties. For example, to include SSL / TLS keys and certificates.
quarkus.native.resources.includes = certs/*.pem,certs.*.keyMore information about selecting resources for inclusion in the native executable can be found in the native mode guide.
2.45.4. Camel Quarkus limitations
2.45.4.1. Integration with Quarkus gRPC is not supported
At present there is no support for integrating Camel Quarkus gRPC with Quarkus gRPC. If you have both the camel-quarkus-grpc and quarkus-grpc extension dependency on the classpath, you are likely to encounter problems at build time when compiling your application.
2.45.5. Additional Camel Quarkus configuration
| Configuration property | Type | Default |
|---|---|---|
|
If |
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Camel Quarkus gRPC code generation can scan application dependencies for .proto files to generate Java stubs from them. This property sets the scope of the dependencies to scan. Applicable values: - none - default - don’t scan dependencies - a comma separated list of groupId:artifactId coordinates to scan - all - scan all dependencies |
|
|
|
Camel Quarkus gRPC code generation can scan dependencies for .proto files that can be imported by protos in this applications. Applicable values: - none - default - don’t scan dependencies - a comma separated list of groupId:artifactId coordinates to scan - all - scan all dependencies The default is com.google.protobuf:protobuf-java. |
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[[quarkus-camel-grpc-codegen-scan-for-proto-includes—scan-for-proto-includes]] Package path or file glob pattern includes per dependency containing .proto files to be considered for inclusion. |
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[[quarkus-camel-grpc-codegen-scan-for-proto-excludes—scan-for-proto-excludes]] Package path or file glob pattern includes per dependency containing .proto files to be considered for exclusion. |
|
Configuration property fixed at build time. All other configuration properties are overridable at runtime.
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