How can I run a command line tool in response to an HTTP Request in Vapor?

Question

I have a node.js command line tool that I'd like to run in order to generate an asset in response to an HTTP Request that I receive in Vapor 4. Is it possible to do this?

Answer 1

I guess it is something like this

func requestHandler(_ req: Request) throws -> EventLoopFuture<HTTPStatus> {
    let promise = req.eventLoop.makePromise(of: HTTPStatus.self)
    let process = Process()
    // e.g. use `which node` to find path to `node`
    process.executableURL = URL(fileURLWithPath: "/path/to/binary") // e.g. /usr/bin/node
    
    // in which folder execute the command, it is optional
    process.currentDirectoryPath = "/path/to/folder"
    
    // optional arguments, e.g. if your arguments are -c release then it should be ["-c", "release"]
    process.arguments = ["arg1", "arg2", "argN"]
    
    // wait for termination in closure
    process.terminationHandler = { process in
        switch process.terminationStatus {
        // probably normal termination via SIGTERM or when process successfully finished
        case 0:
            promise.succeed(.ok)
        default:
            promise.fail(Abort(.failedDependency, reason: "Process finished with code \(process.terminationStatus)"))
        }
    }
    
    // don't forget to launch it
    try process.run()
    
    return promise.futureResult
}