cln-grpc-client

A gRPC client for Core Lightning (CLN).

cln-grpc-client-starter

A module containing a Spring Boot Starter is also available.

Table of Contents

• Install
• Development
• Contributing
• Resources
• License

Install

Download from Maven Central.

Gradle

repositories {
    mavenCentral()
}

implementation "io.github.theborakompanioni:cln-grpc-client-core:${clnGrpcClientVersion}"

Maven

<dependency>
    <groupId>io.github.theborakompanioni</groupId>
    <artifactId>cln-grpc-client-core</artifactId>
    <version>${clnGrpcClient.version}</version>
</dependency>

Development

Requirements

• java >=17
• docker

Build

./gradlew build -x test

Test

./gradlew test integrationTest --rerun-tasks

Dependency Verification

Gradle is used for checksum and signature verification of dependencies.

# write metadata for dependency verification
./gradlew --write-verification-metadata pgp,sha256 --export-keys
# update buildscript dependency locks
./gradlew dependencies --write-locks

See Gradle Userguide: Verifying dependencies for more information.

Checkstyle

Checkstyle with adapted google_checks is used for checking Java source code for adherence to a Code Standard.

# check for code standard violations with checkstyle
./gradlew checkstyleMain --rerun-tasks

SpotBugs

SpotBugs is used for static code analysis.

# invoke static code analysis with spotbugs
./gradlew spotbugsMain --rerun-tasks

Troubleshooting

ManagedChannelProvider$ProviderNotFoundException

Caused by: io.grpc.ManagedChannelProvider$ProviderNotFoundException: No functional channel service provider found. Try adding a dependency on the grpc-okhttp, grpc-netty, or grpc-netty-shaded artifact

add a channel service provider implementation, e.g.

implementation "io.grpc:grpc-netty-shaded:${grpcVersion}"

Hint: The above section should currently not apply, as grpc-netty-shaded is included as dependency. However, this dependency might be removed in future releases.

Error loading shared library libio_grpc_netty_shaded_netty_tcnative-*.so

See: https://github.com/grpc/grpc-java/blob/master/SECURITY.md#netty

Contributing

All contributions and ideas are always welcome. For any question, bug or feature request, please create an issue. Before you start, please read the contributing guidelines.

Resources

• Bitcoin: https://bitcoin.org/en/getting-started
• Lightning Network: https://lightning.network

---

• cln (GitHub): https://github.com/ElementsProject/lightning (Docker)
• cln protobuf: https://github.com/ElementsProject/lightning/tree/master/cln-grpc/proto
• Protocol Buffers: https://protobuf.dev/
• gRPC: https://grpc.io/
• grpc-java (GitHub): https://github.com/grpc/grpc-java
• grpc-java Security: https://github.com/grpc/grpc-java/blob/master/SECURITY.md

License

The project is licensed under the Apache License. See LICENSE for details.