生产环境Firebase Function调用失败（iOS/Swift）：重定向过多问题

问题场景 #

在iOS/Swift中调用Firebase Function的代码如下：

let functions = Functions.functions()
func callWrapper(funcName: String, data: Any? = nil) async ->  [String: Any]? {
    do {
        let result = try await functions.httpsCallable(funcName).call(data)
        return result.data as? [String : Any]
    } catch {
        if let error = error as NSError? {
            if error.domain == FunctionsErrorDomain {
                let code = FunctionsErrorCode(rawValue: error.code)
                let message = error.localizedDescription
                let details = error.userInfo[FunctionsErrorDetailsKey]
            }
            //todo handle
            print(error)
        }
        return nil
    }
}

调用时出现以下错误：

2023-01-05 22:29:48.821609+0200 wallpapers[41492:641302] Task
<50374BAD-C312-450E-9770-B8300BE8FDB9>.<1> finished with error [-1007]
Error Domain=NSURLErrorDomain Code=-1007 "too many HTTP redirects"
UserInfo={NSLocalizedDescription=too many HTTP redirects,
NSErrorFailingURLStringKey=https://accounts.google.com/v3/signin/rejected?continue=https://uc.appengine.google.com/_ah/conflogin?state%3D~AJKiYcH_jc-hcv6OubZGrM13BmNN37rWX4x6rmTm7rZ4-Lqnr9Kk2C00oVNYR97TOiJ8lcR7vP91c9rv6o89HuwIlj85hxjrj63gbmu1jzGKzkU6S_kvHXv7yGdtaOWJnImTm02c6w9igKt3PbbWcawMsOafXEizRAd8jrT0jSe704DhXZ51m8IgAKv0kXxnblLuu3-DFmm-Uvi30sCPXIRGr_XG2DrMenI-zYGRjTiXf2uBVzIom7nVmKoCxIS7dGTvQozrDisq&dsh=S-1861899242:1672950586288679&flowEntry=ServiceLogin&flowName=WebLiteSignIn&ifkv=AeAAQh7QjO_naDvlYC2CVX-wduN9ft7CbGKMTlrMDHmAba7cHNPiDVDd4AQJzvAJgPnBpbS7sCeK0w&rhlk=no&rrk=32,
NSErrorFailingURLKey=https://accounts.google.com/v3/signin/rejected?continue=https://uc.appengine.google.com/_ah/conflogin?state%3D~AJKiYcH_jc-hcv6OubZGrM13BmNN37rWX4x6rmTm7rZ4-Lqnr9Kk2C00oVNYR97TOiJ8lcR7vP91c9rv6o89HuwIlj85hxjrj63gbmu1jzGKzkU6S_kvHXv7yGdtaOWJnImTm02c6w9igKt3PbbWcawMsOafXEizRAd8jrT0jSe704DhXZ51m8IgAKv0kXxnblLuu3-DFmm-Uvi30sCPXIRGr_XG2DrMenI-zYGRjTiXf2uBVzIom7nVmKoCxIS7dGTvQozrDisq&dsh=S-1861899242:1672950586288679&flowEntry=ServiceLogin&flowName=WebLiteSignIn&ifkv=AeAAQh7QjO_naDvlYC2CVX-wduN9ft7CbGKMTlrMDHmAba7cHNPiDVDd4AQJzvAJgPnBpbS7sCeK0w&rhlk=no&rrk=32,
_NSURLErrorRelatedURLSessionTaskErrorKey=(
"LocalDataTask <50374BAD-C312-450E-9770-B8300BE8FDB9>.<1>" ), _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <50374BAD-C312-450E-9770-B8300BE8FDB9>.<1>,
NSUnderlyingError=0x6000005f7c00 {Error Domain=kCFErrorDomainCFNetwork
Code=-1007 "(null)"}}.

但使用本地Firebase模拟器时可以正常运行：

functions.useEmulator(withHost: "localhost", port: 5001)

问题解答 #

Firebase Functions允许未授权用户调用，但需要正确配置函数的权限规则，你遇到的too many HTTP redirects错误正是因为权限配置不当，导致请求被强制跳转到认证页面，进而引发循环重定向。

解决步骤如下：

• 配置云函数IAM权限

  1. 进入Firebase控制台，打开「云函数」页面
  2. 找到目标函数，点击进入后切换到「权限」标签页
  3. 点击「添加主體」，输入allUsers并选择该主体
  4. 为allUsers授予「Cloud Functions Invoker」角色
     注意：公开函数存在安全风险，请确保函数内部没有敏感操作，或在函数逻辑中添加必要的校验逻辑（比如参数验证）

• 检查云函数代码中的认证逻辑
  如果你的云函数代码中存在强制校验用户身份的逻辑（比如判断context.auth非空），需要移除或调整这部分代码，允许匿名用户访问

• 确认客户端初始化正确
  确保App启动时已正确初始化FirebaseApp，你的Swift调用代码本身无需修改，保持匿名调用即可

内容的提问来源于stack exchange，提问作者Olexander Korenyuk