Support Linux Build

[xanderdunn]

Currently, this project doesn't build on Linux. Using version 1.1.1:

$ which swift
/home/xander/swift-tensorflow-RELEASE-0.10-cuda10.2-cudnn7-ubuntu18.04/usr/bin/swift
$ swift --version
Swift version 5.3-dev (LLVM 55d27a5828, Swift 6a5d84ec08)
Target: x86_64-unknown-linux-gnu
$ swift build
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:32:29: error: 'URLResponse' is unavailable: This type has moved to the FoundationNetworking module. Import that module to use it.
        case noDataReceived(URLResponse?)
                            ^~~~~~~~~~~
Foundation.URLResponse:2:18: note: 'URLResponse' has been explicitly marked unavailable here
public typealias URLResponse = AnyObject
                 ^
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:40:29: error: 'URLResponse' is unavailable: This type has moved to the FoundationNetworking module. Import that module to use it.
        case noDataReceived(URLResponse?)
                            ^~~~~~~~~~~
Foundation.URLResponse:2:18: note: 'URLResponse' has been explicitly marked unavailable here
public typealias URLResponse = AnyObject
                 ^
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:216:18: error: 'URLSession' is unavailable: This type has moved to the FoundationNetworking module. Import that module to use it.
    let session: URLSession
                 ^~~~~~~~~~
Foundation.URLSession:2:18: note: 'URLSession' has been explicitly marked unavailable here
public typealias URLSession = AnyObject
                 ^
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:132:34: error: cannot find type 'CFError' in scope
            var error: Unmanaged<CFError>?
                                 ^~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:133:31: error: cannot find 'kSecAttrKeyType' in scope
            let attributes = [kSecAttrKeyType: kSecAttrKeyTypeRSA, kSecAttrKeyClass: kSecAttrKeyClassPrivate, kSecAttrKeySizeInBits: 256] as CFDictionary
                              ^~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:133:48: error: cannot find 'kSecAttrKeyTypeRSA' in scope
            let attributes = [kSecAttrKeyType: kSecAttrKeyTypeRSA, kSecAttrKeyClass: kSecAttrKeyClassPrivate, kSecAttrKeySizeInBits: 256] as CFDictionary
                                               ^~~~~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:133:68: error: cannot find 'kSecAttrKeyClass' in scope
            let attributes = [kSecAttrKeyType: kSecAttrKeyTypeRSA, kSecAttrKeyClass: kSecAttrKeyClassPrivate, kSecAttrKeySizeInBits: 256] as CFDictionary
                                                                   ^~~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:133:86: error: cannot find 'kSecAttrKeyClassPrivate' in scope
            let attributes = [kSecAttrKeyType: kSecAttrKeyTypeRSA, kSecAttrKeyClass: kSecAttrKeyClassPrivate, kSecAttrKeySizeInBits: 256] as CFDictionary
                                                                                     ^~~~~~~~~~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:133:111: error: cannot find 'kSecAttrKeySizeInBits' in scope
            let attributes = [kSecAttrKeyType: kSecAttrKeyTypeRSA, kSecAttrKeyClass: kSecAttrKeyClassPrivate, kSecAttrKeySizeInBits: 256] as CFDictionary
                                                                                                              ^~~~~~~~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:134:36: error: cannot find 'SecKeyCreateWithData' in scope
            guard let privateKey = SecKeyCreateWithData(key as CFData, attributes, &error) else {
                                   ^~~~~~~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:137:35: error: cannot find 'SecKeyCreateSignature' in scope
            guard let signature = SecKeyCreateSignature(privateKey, .rsaSignatureMessagePKCS1v15SHA256, data as CFData, &error) as Data? else {
                                  ^~~~~~~~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:229:19: error: 'URLSession' is unavailable: This type has moved to the FoundationNetworking module. Import that module to use it.
        session = URLSession(configuration: .ephemeral, delegate: nil, delegateQueue: operationQueue)
                  ^~~~~~~~~~
Foundation.URLSession:2:18: note: 'URLSession' has been explicitly marked unavailable here
public typealias URLSession = AnyObject
                 ^
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:240:27: error: cannot find 'URLRequest' in scope
            var request = URLRequest(url: url)
                          ^~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:305:27: error: cannot find 'URLRequest' in scope
            var request = URLRequest(url: url)
                          ^~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:387:29: error: cannot find 'applyingTransform' in scope
        let logId = String((applyingTransform(.toLatin, reverse: false) ?? self)
                            ^~~~~~~~~~~~~~~~~
.build/checkouts/GoogleCloudLogging/Sources/GoogleCloudLogging/GoogleCloudLogging.swift:40:29: error: 'URLResponse' is unavailable: This type has moved to the FoundationNetworking module. Import that module to use it.
        case noDataReceived(URLResponse?)
                            ^~~~~~~~~~~
Foundation.URLResponse:2:18: note: 'URLResponse' has been explicitly marked unavailable here
public typealias URLResponse = AnyObject
                 ^

Some of these errors could be resolved simply by changing import Foundation to:

import Foundation
#if canImport(FoundationNetworking)
    import FoundationNetworking
#endif

It looks like the authentication portions of it would need to be replaced by either CryptoSwift or google-auth-library-swift, both of which support Linux. The latter is Google's official library for authenticating with Google Cloud and may readily replace this functionality.

[DnV1eX]

Thanks, @xanderdunn. Initially, this library used Google's OAuth implementation, but I intentionally sacrificed Linux support to avoid third-party dependencies. If anyone would like to share thoughts on the topic, welcome to comment!

[Mordil]

I think it's totally reasonable to use Apple and event SSWG incubating projects as dependencies, and we now have SwiftCrypto

[diegotl]

We're in 2024, this project seems abandoned but I still use it in my projects and wanted to use it in one of my Vapor apps, which runs in a linux server.

Turns out the JWT part that depends on Security framework (macOS-only) can be replaced using JWTKit, which is already a dependency of Vapor. I could make it work.

For a while I run my own fork with few other modifications, but if people are interested (including @DnV1eX) I can prepare and make a PR here adding the linux support.