Swift ETCD client

Warning

This repository was a Google Summer of Code project that didn't reach feature completness to offer a full ETCD client. For now we have archived the repository to reduce our maintenance burden but if you are interested in taking on the maintenance please reach out to the Swift Server Workgroup in the Swift forums.

Swift ETCD is a Swift Package that provides a convenient way to communicate with etcd servers.

Getting Started

To depend on Swift ETCD within your own project, you can add a dependencies clause to your Package.swift

dependencies: [
    .package(url: "https://github.com/swift-server/swift-etcd-client-gsoc")
]

Overview

The ETCD Client allows for communication with an ETCD Server. The Client takes care of establishing a connection, and handling asynchronous execution of commands.

Here's an example of how you can use the ETCD Client

struct Example {
    static func main() async throws {
        let eventLoopGroup = MultiThreadedEventLoopGroup.singleton
        do {
            let etcdClient = EtcdClient(host: "localhost", port: 2379, eventLoopGroup: eventLoopGroup)
            try await withThrowingTaskGroup(of: Void.self) { group in
                group.addTask {
                    do {
                        try await etcdClient.watch("foo") { sequence in
                            var iterator = sequence.makeAsyncIterator()
                            while let event = try await iterator.next() {
                                print(event)
                            }
                        }
                    } catch {
                        print("Error watching key: \(error)")
                    }
                }
                // Sleeping for a second to let the watch above setup
                try await Task.sleep(for: .seconds(1))
                
                try await etcdClient.set("foo", value: "bar")
                let key = "foo".data(using: .utf8)!
                let rangeRequest = RangeRequest(key: key)
                if let value = try await etcdClient.getRange(rangeRequest) {
                    if let stringValue = String(data: value, encoding: .utf8) {
                        print("Value is: \(stringValue)")
                        let deleteRangeRequest = DeleteRangeRequest(key: key)
                        try await etcdClient.deleteRange(deleteRangeRequest)
                        print("Key deleted")
                        
                        // Trying to get the value again
                        let deletedValue = try await etcdClient.getRange(rangeRequest)
                        if deletedValue == nil {
                            print("Key not found after deletion")
                        } else {
                            print("Value after deletion: \(deletedValue!)")
                        }
                    } else {
                        print("Unable to get value")
                    }
                } else {
                    print("Key not found")
                }
                try await Task.sleep(for: .seconds(2))
                do {
                    try await etcdClient.set("foo", value: "updated_value")
                } catch {
                    print("Error setting updated value: \(error)")
                }
            }
        } catch {
            print("Error: \(error)")
        }
    }
}

Contributing

To contribute to this package, please look at CONTRIBUTING.md