如何在 CDK 应用程序中获取 RDS 实例主机名？

Posted 2023-03-04

【中文标题】如何在 CDK 应用程序中获取 RDS 实例主机名？

【英文标题】：How to get RDS instance hostname in CDK app?

【发布时间】：2020-04-21 13:54:02

【问题描述】：

我正在使用适用于 .NET 的 AWS CDK 创建一个堆栈，该堆栈由一个 VPC、一个 RDS 数据库实例和 ECS 中的应用程序负载平衡 Fargate 服务组成。我部署到 ECS 的容器需要通过环境变量设置 RDS 数据库的连接信息，但我不确定如何访问该信息。下面是我的 CDK 代码。

using Amazon.CDK;
using EC2 = Amazon.CDK.AWS.EC2;
using ECS = Amazon.CDK.AWS.ECS;
using RDS = Amazon.CDK.AWS.RDS;

namespace PersonalSecOps

    public class PersonalSecOpsStack : Stack
    
        internal PersonalSecOpsStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
        
            var vpc = new EC2.Vpc(this, "PersonalSecOpsVpc", new EC2.VpcProps
            
                MaxAzs = 3 // Default is all AZs in region
            );

            var mysql = new RDS.DatabaseInstance(this, "PersonalSecOpsRds", new RDS.DatabaseInstanceProps
            
                Engine = RDS.DatabaseInstanceEngine.MYSQL,
                PreferredBackupWindow = "05:00-06:00",
                BackupRetention = Duration.Days(7),
                RemovalPolicy = RemovalPolicy.DESTROY,
                DeletionProtection = false,
                MasterUsername = "admin",
                InstanceClass = EC2.InstanceType.Of(EC2.InstanceClass.BURSTABLE2, EC2.InstanceSize.MICRO),
                Vpc = vpc,
                InstanceIdentifier = "PersonalSecOpsRds"
            );

            var ecsCluster = new ECS.Cluster(this, "PersonalSecOpsEcs", new ECS.ClusterProps
            
                Vpc = vpc
            );

            var nextCloudService = new ECS.Patterns.ApplicationLoadBalancedFargateService(this, "NextcloudService", new ECS.Patterns.ApplicationLoadBalancedFargateServiceProps
            
                Cluster = ecsCluster,
                DesiredCount = 1,
                TaskImageOptions = new ECS.Patterns.ApplicationLoadBalancedTaskImageOptions
                
                    Image = ECS.ContainerImage.FromRegistry("nextcloud"),
                    Secrets = 
                    
                         "MYSQL_PASSWORD", ??? 
                    ,
                    Environment = 
                         "MYSQL_DATABASE", "Nextcloud" ,
                         "MYSQL_USER", "admin" ,
                         "MYSQL_HOST", ??? 
                     
                ,
                MemoryLimitMiB = 2048,
                PublicLoadBalancer = true
            );
        
    

注意两个“？？？”我试图在容器上设置MYSQL_PASSWORD 和MYSQL_HOST 环境变量。我在某处读到 RDS 会自动生成 MasterUserPassword 并将其存储在 Secret Manager 中，但我不确定如何将其取出。另外，我需要 RDS 实例的主机名。在创建实例时，我无法找到一种方法来显式设置它，否则我只会这样做。

我这样做对吗？

【参考方案1】：

感谢 Reddit 上的 kingofpoptart 帮助回答 this question。

using Amazon.CDK;
using EC2 = Amazon.CDK.AWS.EC2;
using ECS = Amazon.CDK.AWS.ECS;
using RDS = Amazon.CDK.AWS.RDS;

namespace PersonalSecOps

    public class PersonalSecOpsStack : Stack
    
        internal PersonalSecOpsStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
        
            var vpc = new EC2.Vpc(this, "PersonalSecOpsVpc", new EC2.VpcProps
            
                MaxAzs = 3 // Default is all AZs in region
            );

            var mySqlPassword = new Secret(this, "PersonalSecOpsMySqlPassword", new SecretProps
            
                GenerateSecretString = new SecretStringGenerator
                
                    PasswordLength = 20
                
            );

            var mySql = new RDS.DatabaseInstance(this, "PersonalSecOpsRds", new RDS.DatabaseInstanceProps
            
                Engine = RDS.DatabaseInstanceEngine.MYSQL,
                PreferredBackupWindow = "05:00-06:00",
                BackupRetention = Duration.Days(7),
                RemovalPolicy = RemovalPolicy.DESTROY,
                DeletionProtection = false,
                MasterUsername = "admin",
                MasterUserPassword = mySqlPassword.SecretValue,
                InstanceClass = EC2.InstanceType.Of(EC2.InstanceClass.BURSTABLE2, EC2.InstanceSize.MICRO),
                Vpc = vpc,
                InstanceIdentifier = "PersonalSecOpsRds"
            );

            var ecsCluster = new ECS.Cluster(this, "PersonalSecOpsEcs", new ECS.ClusterProps
            
                Vpc = vpc
            );

            var nextCloudService = new ECS.Patterns.ApplicationLoadBalancedFargateService(this, "NextcloudService", new ECS.Patterns.ApplicationLoadBalancedFargateServiceProps
            
                Cluster = ecsCluster,
                DesiredCount = 1,
                TaskImageOptions = new ECS.Patterns.ApplicationLoadBalancedTaskImageOptions
                
                    Image = ECS.ContainerImage.FromRegistry("nextcloud"),
                    Secrets = 
                    
                         "MYSQL_PASSWORD", ECS.Secret.FromSecretsManager(mySqlPassword) 
                    ,
                    Environment = 
                         "MYSQL_DATABASE", "Nextcloud" ,
                         "MYSQL_USER", "admin" ,
                         "MYSQL_HOST", mySql.DbInstanceEndpointAddress 
                     
                ,
                MemoryLimitMiB = 2048,
                PublicLoadBalancer = true
            );
        
    

【讨论】：

简而言之：mySql.DbInstanceEndpointAddress