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A wrapper for the NIOSSHClient example found in the apple/swift-nio-ssh repo. It can be used to call commands on the connected ssh server.
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let ssh = SwiftNioSshWrapper(host: "...", port: 22, user: "...", password: "...") | |
do { | |
try ssh.run(command: "pwd") | |
} catch { | |
print(error) | |
} |
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import Foundation | |
import Dispatch | |
import NIO | |
import NIOSSH | |
public class SwiftNioSshWrapper { | |
let host: String | |
let port: Int | |
let user: String | |
let password: String | |
public init(host: String, port: Int, user: String, password: String) { | |
print("Initializing the wrapper") | |
self.host = host | |
self.port = port | |
self.user = user | |
self.password = password | |
} | |
// Just prints the config | |
public func printConfig() { | |
print("Config: \(host), \(port), \(user), \(password)") | |
} | |
// This file contains an example NIO SSH client. As NIO SSH is currently under active | |
// development this file doesn't currently do all that much, but it does provide a binary you | |
// can kick off to get a feel for how NIO SSH drives the connection live. As the feature set of | |
// NIO SSH increases we'll be adding to this client to try to make it a better example of what you | |
// can do with NIO SSH. | |
final class ErrorHandler: ChannelInboundHandler { | |
typealias InboundIn = Any | |
func errorCaught(context: ChannelHandlerContext, error: Error) { | |
print("Error in pipeline: \(error)") | |
context.close(promise: nil) | |
} | |
} | |
final class AcceptAllHostKeysDelegate: NIOSSHClientServerAuthenticationDelegate { | |
func validateHostKey(hostKey: NIOSSHPublicKey, validationCompletePromise: EventLoopPromise<Void>) { | |
// Do not replicate this in your own code: validate host keys! This is a | |
// choice made for expedience, not for any other reason. | |
validationCompletePromise.succeed(()) | |
} | |
} | |
public func run(command: String) throws -> Void { | |
let group = MultiThreadedEventLoopGroup(numberOfThreads: 1) | |
defer { | |
try! group.syncShutdownGracefully() | |
} | |
let bootstrap = ClientBootstrap(group: group) | |
.channelInitializer { channel in | |
channel.pipeline.addHandlers([NIOSSHHandler(role: .client(.init(userAuthDelegate: InteractivePasswordPromptDelegate(username: self.user, password: self.password), serverAuthDelegate: AcceptAllHostKeysDelegate())), allocator: channel.allocator, inboundChildChannelInitializer: nil), ErrorHandler()]) | |
} | |
.channelOption(ChannelOptions.socket(SocketOptionLevel(SOL_SOCKET), SO_REUSEADDR), value: 1) | |
.channelOption(ChannelOptions.socket(SocketOptionLevel(IPPROTO_TCP), TCP_NODELAY), value: 1) | |
do { | |
print("connect via ssh") | |
let channel = try bootstrap.connect(host: self.host, port: self.port).wait() | |
// We've been asked to exec. | |
print("channel created") | |
let exitStatusPromise = channel.eventLoop.makePromise(of: Int.self) | |
let childChannel: Channel = try! channel.pipeline.handler(type: NIOSSHHandler.self).flatMap { sshHandler in | |
let promise = channel.eventLoop.makePromise(of: Channel.self) | |
sshHandler.createChannel(promise) { childChannel, channelType in | |
guard channelType == .session else { | |
return channel.eventLoop.makeFailedFuture(SSHClientError.invalidChannelType) | |
} | |
return childChannel.pipeline.addHandlers([ExampleExecHandler(command: command, completePromise: exitStatusPromise), ErrorHandler()]) | |
} | |
return promise.futureResult | |
}.wait() | |
// Wait for the connection to close | |
print("closing") | |
try! childChannel.closeFuture.wait() | |
print("child channel closed") | |
let exitStatus = try! exitStatusPromise.futureResult.wait() | |
print("exist status promise awaited") | |
try! channel.close().wait() | |
print("all closed") | |
print(exitStatus) | |
// Exit like we're the command. | |
// exit(Int32(exitStatus)) | |
} catch { | |
print("could not connect via SSH") | |
return | |
} | |
} | |
} |
@t089 when I try this, I'm getting an exception at the line try! childChannel.close().wait()
MBeat/SwiftNioSshWrapper.swift:90: Fatal error: 'try!' expression unexpectedly raised an error: NIOCore.ChannelError.alreadyClosed
2022-08-30 09:29:16.087351+0200 MBeat[13289:5465932] MBeat/SwiftNioSshWrapper.swift:90: Fatal error: 'try!' expression unexpectedly raised an error: NIOCore.ChannelError.alreadyClosed
So I commented out try! childChannel.close().wait()
, and at least, it runs through once. But when I call a second command, I get an exception in the line let childChannel: Channel = try! ... .wait()
MBeat/SwiftNioSshWrapper.swift:74: Fatal error: 'try!' expression unexpectedly raised an error: NIOCore.ChannelError.eof
2022-08-30 09:32:14.539830+0200 MBeat[13485:5469283] MBeat/SwiftNioSshWrapper.swift:74: Fatal error: 'try!' expression unexpectedly raised an error: NIOCore.ChannelError.eof
It looks like that the channel doesn't reset the stream.
The reason for my assumption is purely missing knowledge. I tried to understand ExampleExecHandler but failed. So I assume that I'm my wrapper has a few more issues. (apart from the main issue that I can only run it once 🤣 )
hm, ok, I will try to find some time to take a closer look
Any way to upload file to ssh server from iOS app?
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Why do you assume the child channel is closed after sending the command? Looking at
ExampleExecHandler
it does not seem like that.Have you tried first waiting on the exit status and then actively closing the channel?