Question

我安装了gem webmock，它在测试套件中阻止了外部连接。安装后，运行测试套件时出现意外结果。

我有点困惑为什么aws-sdk在初始化时需要连接到169.254.169.254？

rspec spec/models/concerns/posconcern_spec.rb
[Coveralls] Set up the SimpleCov formatter.
[Coveralls] Using SimpleCov's 'rails' settings.

An error occurred while loading ./spec/models/concerns/posconcern_spec.rb.
Failure/Error: require File.expand_path('../../config/environment', __FILE__)

WebMock::NetConnectNotAllowedError:
  Real HTTP connections are disabled. Unregistered request: GET http://169.254.169.254/latest/meta-data/iam/security-credentials/ with headers {'Accept'=>'*/*', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'User-Agent'=>'Ruby'}

  You can stub this request with the following snippet:

  stub_request(:get, "http://169.254.169.254/latest/meta-data/iam/security-credentials/").
    with(headers: {'Accept'=>'*/*', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'User-Agent'=>'Ruby'}).
    to_return(status: 200, body: "", headers: {})

  ============================================================
# /home/andey/.rvm/gems/ruby-2.3.4/gems/webmock-3.1.0/lib/webmock/http_lib_adapters/net_http.rb:114:in `request'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:109:in `http_get'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:90:in `block (2 levels) in get_credentials'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:105:in `open_connection'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:88:in `block in get_credentials'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:121:in `retry_errors'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:87:in `get_credentials'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:73:in `block in refresh'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:121:in `retry_errors'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:72:in `refresh'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/refreshing_credentials.rb:20:in `initialize'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/instance_profile_credentials.rb:51:in `initialize'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/credential_provider_chain.rb:90:in `new'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/credential_provider_chain.rb:90:in `instance_profile_credentials'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/credential_provider_chain.rb:12:in `block in resolve'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/credential_provider_chain.rb:11:in `each'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/credential_provider_chain.rb:11:in `resolve'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/aws-sdk-core/plugins/request_signer.rb:37:in `block in <class:RequestSigner>'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:70:in `call'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:205:in `block in resolve_defaults'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:57:in `each'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:57:in `each'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:204:in `resolve_defaults'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:200:in `value_at'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:189:in `block in resolve'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:189:in `resolve'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:177:in `apply_defaults'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/configuration.rb:150:in `build!'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/base.rb:68:in `build_config'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/base.rb:19:in `initialize'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/aws-sdk-core-2.10.52/lib/seahorse/client/base.rb:105:in `new'
# ./config/initializers/aws.rb:1:in `<top (required)>'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/activesupport-4.2.9/lib/active_support/dependencies.rb:268:in `load'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/activesupport-4.2.9/lib/active_support/dependencies.rb:268:in `block in load'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/activesupport-4.2.9/lib/active_support/dependencies.rb:240:in `load_dependency'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/activesupport-4.2.9/lib/active_support/dependencies.rb:268:in `load'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/engine.rb:652:in `block in load_config_initializer'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/activesupport-4.2.9/lib/active_support/notifications.rb:166:in `instrument'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/engine.rb:651:in `load_config_initializer'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/engine.rb:616:in `block (2 levels) in <class:Engine>'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/engine.rb:615:in `each'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/engine.rb:615:in `block in <class:Engine>'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/initializable.rb:30:in `instance_exec'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/initializable.rb:30:in `run'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/initializable.rb:55:in `block in run_initializers'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/initializable.rb:44:in `each'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/initializable.rb:44:in `tsort_each_child'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/initializable.rb:54:in `run_initializers'
# /home/andey/.rvm/gems/ruby-2.3.4/gems/railties-4.2.9/lib/rails/application.rb:352:in `initialize!'
# ./config/environment.rb:5:in `<top (required)>'
# ./spec/rails_helper.rb:3:in `require'
# ./spec/rails_helper.rb:3:in `<top (required)>'
# ./spec/models/concerns/posconcern_spec.rb:1:in `require'
# ./spec/models/concerns/posconcern_spec.rb:1:in `<top (required)>'

回购的相关链接：

https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-core/lib/aws-sdk-core/instance_profile_credentials.rb#L45

Answer 1

它正在尝试连接到AWS元数据服务器以获取AWS凭据。所有AWS服务器都应该能够连接到内部元数据服务器。

我安装了gem webmock，它阻止了外部连接测试套件

你是怎么阻止它的？防火墙吗？添加规则以允许流量到169.254.169.254或存根。

该脚本正在尝试连接到AWS服务。为此，它需要可以通过多种方式提供的凭证。一种方法是使用AWS IAM角色并从元数据服务器（169.254.169.254）动态获取凭据。您的脚本正在连接到169.254.169.254以获取凭据。它可以用于以后连接到AWS服务。

Answer 2

这是对@helloV的回答。

的完整文档

http://169.254.169.254/latest/meta-data/iam/security-credentials/

实例上的应用程序检索安全凭证由实例元数据项的角色提供 IAM /安全证书/角色名称。申请被授予您为其定义的操作和资源的权限角色通过与角色关联的安全凭证。这些安全凭证是临时的，我们会自动轮换它们。我们至少在会议开始前五分钟提供新凭证旧凭证到期。

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html#instance-metadata-security-credentials

Answer 3

在研究如何对其进行存续方面经历了艰难的时期。在这里分享我的发现，希望对其他人有帮助。

由于AWS使用服务名称来获取多个服务（例如S3，任何IAM角色，SQS等）的凭证。但是，在处理IAM角色时，AWS命中http://169.254.169.254/latest/meta-data/iam/security-credentials/并返回附加到机器上的角色名称，并使用响应返回到卷http://169.254.169.254/latest/meta-data/iam/security-credentials/# {role}。因此，我们需要对两个卷发进行存根处理，以便成功模拟IAM角色。下面是相同的代码。

def self.auth(params = {})
  status = params[:status].presence || 200
  url = 'http://169.254.169.254/latest/meta-data/iam/security-credentials/'
  WebMock.stub_request(:get, url)
      .with({headers: request_headers}.compact)
      .to_return(status: status, body: 'SampleRole', headers: {})
end

def self.role_auth(role = 'SampleRole')
  url = "http://169.254.169.254/latest/meta-data/iam/security-credentials/#{role}"
  WebMock.stub_request(:get, url)
      .with({headers: request_headers}.compact)
      .to_return(status: 200, body: sample_response, headers: {})
end

private

def self.request_headers
  {
      'Accept': '*/*',
      'Accept-Encoding': 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
      'User-Agent': 'aws-sdk-ruby3/3.21.2'
  }.with_indifferent_access
end

def self.sample_response
  {
      Code: 'Success',
      LastUpdated: '2020-05-08T05:55:23Z',
      Type: 'AWS-HMAC',
      AccessKeyId: Faker::Lorem.characters(10),
      SecretAccessKey: Faker::Lorem.characters(20),
      Token: Faker::Lorem.characters(60),
      Expiration: '2020-05-08T12:00:45Z'
  }.to_json
end

因此，无论何时任何rspec使用InstanceCredentials提供程序，都需要在每个rspec的before块中存入上面定义的两个请求。

示例：

before do
 ApiStub::IamCred.auth
 ApiStub::IamCred.role_auth
end

希望有帮助。快乐编码

为什么aws-sdk-ruby在初始化时连接到'169.254.169.254'？

3 个答案: