基于评论中的额外讨论。
使es域完全公开是不可能的。云层不允许这样。因此，有三种选择。下面我将在一个示例的无服务器应用程序中展示其中三个。这只是一个基本的helloworld应用程序，它没有以任何容量使用es域，但是我使用它来验证每个选择是否有效，并且可以使用无服务器框架部署而不会出错。

应用基于ip的条件

这将使您的域只开放访问单个ip地址或ip cidr范围。下面的示例限制对一个单一ip地址的访问。

service: estest

provider:
  name: aws
  runtime: python3.8

  stage: ${opt:stage, 'dev'}
  region: ${opt:region, 'us-east-1'}  

functions:
  hello:
    handler: handler.hello

resources:
  Resources:
    PostsSearch:
      Type: AWS::Elasticsearch::Domain
      Properties:
        ElasticsearchVersion: '6.3'
        DomainName: images-search-${self:provider.stage}
        ElasticsearchClusterConfig:
          DedicatedMasterEnabled: false
          InstanceCount: 1
          ZoneAwarenessEnabled: false
          InstanceType: t2.small.elasticsearch
        EBSOptions:
          EBSEnabled: true
          Iops: 0
          VolumeSize: 10
          VolumeType: 'gp2'
        AccessPolicies:
          Version: '2012-10-17'
          Statement:
            - Effect: Allow
              Principal:
                AWS: '*'
              Action: 'es:ESHttp*'
              Resource: !Sub "arn:aws:es:${self:provider.region}:${AWS::AccountId}:domain/images-search-${self:provider.stage}/*"
              Condition:
                IpAddress:
                   aws:SourceIp: ["12.13.14.15"]

限制委托人

您可以将对es域的访问限制为选定的iam用户或角色。这样，只有给定的iam用户/角色才能访问es域。在下面我使用lambda现有iam角色作为原则。函数及其角色必须已经存在。

service: estest

provider:
  name: aws
  runtime: python3.8

  stage: ${opt:stage, 'dev'}
  region: ${opt:region, 'us-east-1'}  

functions:
  hello:
    handler: handler.hello

resources:
  Resources:
    PostsSearch:
      Type: AWS::Elasticsearch::Domain
      Properties:
        ElasticsearchVersion: '6.3'
        DomainName: images-search-${self:provider.stage}
        ElasticsearchClusterConfig:
          DedicatedMasterEnabled: false
          InstanceCount: 1
          ZoneAwarenessEnabled: false
          InstanceType: t2.small.elasticsearch
        EBSOptions:
          EBSEnabled: true
          Iops: 0
          VolumeSize: 10
          VolumeType: 'gp2'
        AccessPolicies:
          Version: '2012-10-17'
          Statement:
            - Effect: Allow
              Action: 'es:ESHttp*'            
              Principal:
                AWS: !Sub "arn:aws:iam::${AWS::AccountId}:role/service-role/lambda-function-es-role-b44mvudf"
              Resource: !Sub "arn:aws:es:${self:provider.region}:${AWS::AccountId}:domain/images-search-${self:provider.stage}/*"

使用细粒度访问控制

这里的示例使用需要用户名和密码的细粒度控件创建可公开访问的es域。这在自由层中不起作用。我还硬编码了用户名和密码，这显然需要修改并作为参数提供 SSM Parameter store 在实际应用中。

service: estest

provider:
  name: aws
  runtime: python3.8

  stage: ${opt:stage, 'dev'}
  region: ${opt:region, 'us-east-1'}  

functions:
  hello:
    handler: handler.hello

resources:
  Resources:
    PostsSearch:    
      Type: AWS::Elasticsearch::Domain
      Properties: 
        DomainName: images-search-${self:provider.stage}        
        AccessPolicies: !Sub |
          {
            "Version": "2012-10-17",
            "Statement": [
              {
                "Effect": "Allow",
                "Principal": {
                  "AWS": "*"
                },
                "Action": "es:*",
                "Resource": "*"
              }
            ]
          }
        AdvancedSecurityOptions:
            Enabled: true
            InternalUserDatabaseEnabled: true
            MasterUserOptions: 
              MasterUserName: admin
              MasterUserPassword: fD343sfdf!3rf
        EncryptionAtRestOptions: 
          Enabled: true
        NodeToNodeEncryptionOptions:
          Enabled: true
        DomainEndpointOptions:
          EnforceHTTPS: true
        EBSOptions: 
          EBSEnabled: true
          VolumeSize: 20
          VolumeType: gp2
        ElasticsearchClusterConfig: 
          DedicatedMasterEnabled: false
          InstanceCount: 1
          InstanceType: c4.large.elasticsearch
          ZoneAwarenessEnabled: false
        ElasticsearchVersion: 7.7