AWS SDK in Go. 解析数据

huangapple
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英文:

AWS SDK in Go. Parsing data

问题

我正在使用aws-sdk来进行Go语言开发。我想根据实例类型过滤器来描述EC2实例。
以下是我的代码：

  1. ec2Svc := ec2.New(sess, &aws.Config{Credentials: creds})
  2. params := &ec2.DescribeInstanceTypesInput{
  3.     Filters: []*ec2.Filter{
  4.         {
  5.             Name:   aws.String("instance-type"),
  6.             Values: []*string{aws.String("t2*")},
  7.         },
  8.     },
  9. }
  11. result, err := ec2Svc.DescribeInstanceTypes(params)
  12. if err != nil {
  13.     fmt.Println("Error", err)
  14. } else {
  15.     fmt.Println(result.String())
  16. }

这段代码运行良好。result变量的类型是ec2.DescribeInstanceTypeOutput。以下是result的样式：

  1. {
  2.   "InstanceTypes": [
  3.     {
  4.       "AutoRecoverySupported": true,
  5.       "BareMetal": false,
  6.       "BurstablePerformanceSupported": true,
  7.       "CurrentGeneration": true,
  8.       "DedicatedHostsSupported": false,
  9.       "EbsInfo": {
  10.         "EbsOptimizedSupport": "unsupported",
  11.         "EncryptionSupport": "supported",
  12.         "NvmeSupport": "unsupported"
  13.       },
  14.       "FreeTierEligible": false,
  15.       "InstanceStorageSupported": false,
  16.       "InstanceType": "t2.2xlarge",
  17.       "MemoryInfo": {
  18.         "SizeInMiB": 32768
  19.       },
  20.       "NetworkInfo": {
  21.         "DefaultNetworkCardIndex": 0,
  22.         "MaximumNetworkCards": 1,
  23.         "MaximumNetworkInterfaces": 3,
  24.         "NetworkCards": [
  25.           {
  26.             "MaximumNetworkInterfaces": 3
  27.           }
  28.         ],
  29.         "NetworkPerformance": "Moderate"
  30.       },
  31.       "PlacementGroupInfo": {
  32.         "SupportedStrategies": [
  33.           "partition",
  34.           "spread"
  35.         ]
  36.       },
  37.       "ProcessorInfo": {
  38.         "SupportedArchitectures": [
  39.           "x86_64"
  40.         ]
  41.       },
  42.       "SupportedBootModes": [
  43.         "legacy-bios"
  44.       ],
  45.       "SupportedVirtualizationTypes": [
  46.         "hvm"
  47.       ],
  48.       "VCpuInfo": {
  49.         "DefaultCores": 8
  50.       }
  51.     }
  52.   ],
  53.   "NextToken": "asadasdasd"
  54. }

如你所见，这个JSON非常长，我已经删除了其中一些内容以便更易读。我想从中获取一个信息 - MemoryInfo.SizeInMiB，但我不知道如何做到。我尝试使用json.Marshal和json.Unmarshal，但由于ec2.DescribeInstanceTypeOutput类型的原因，我遇到了错误。
获取这个值的唯一方法是创建一个相应的结构，然后进行处理吗？

英文:

I'm using aws-sdk for go. I want to describe EC2 instance based on instance-type filter.
Here's my code:

  1. 	ec2Svc := ec2.New(sess, &aws.Config{Credentials: creds})
  2. 	params := &ec2.DescribeInstanceTypesInput{
  3. 		Filters: []*ec2.Filter{
  4. 			{
  5. 				Name:   aws.String("instance-type"),
  6. 				Values: []*string{aws.String("t2*")},
  7. 			},
  8. 		},
  9. 	}
  11. 	result, err := ec2Svc.DescribeInstanceTypes(params)
  12. 	if err != nil {
  13. 		fmt.Println("Error", err)
  14. 	} else {
  15. 		fmt.Println(result.String())
  16. 	}

This works fine. The type of result variable is *ec2.DescribeInstanceTypeOutput. Here's how result looks like:

  1. {
  2.   InstanceTypes: [{
  3.       AutoRecoverySupported: true,
  4.       BareMetal: false,
  5.       BurstablePerformanceSupported: true,
  6.       CurrentGeneration: true,
  7.       DedicatedHostsSupported: false,
  8.       EbsInfo: {
  9.         EbsOptimizedSupport: "unsupported",
  10.         EncryptionSupport: "supported",
  11.         NvmeSupport: "unsupported"
  12.       },
  13.       FreeTierEligible: false,
  14.       InstanceStorageSupported: false,
  15.       InstanceType: "t2.2xlarge",
  16.       MemoryInfo: {
  17.         SizeInMiB: 32768
  18.       },
  19.       NetworkInfo: {
  20.         DefaultNetworkCardIndex: 0,
  21.         MaximumNetworkCards: 1,
  22.         MaximumNetworkInterfaces: 3,
  23.         NetworkCards: [{
  24.             MaximumNetworkInterfaces: 3,
  25.           }],
  26.         NetworkPerformance: "Moderate"
  27.       },
  28.       PlacementGroupInfo: {
  29.         SupportedStrategies: ["partition","spread"]
  30.       },
  31.       ProcessorInfo: {
  32.         SupportedArchitectures: ["x86_64"],
  33.       },
  34.       SupportedBootModes: ["legacy-bios"],
  35.       SupportedVirtualizationTypes: ["hvm"],
  36.       VCpuInfo: {
  37.         DefaultCores: 8,
  38.       }
  39.     }],
  40.   NextToken: "asadasdasd"
  41. }

As you can see this json is quite long and I've removed some content from it to make more readable. I want to get one information from it - MemoryInfo.SizeInMiB but I don't know how to. I've tried using json.Marshal and json.Unmarshal but I get error because of *ec2.DescribeInstanceTypeOutput type.

Is the only way to get this value is to create some long structure and then using it somehow?

答案1

得分: 1

您不需要创建新的结构，SDK已经提供了这个功能。DescribeInstanceTypes的返回类型是一个指向DescribeInstanceTypesOutput对象的指针。

您可以通过以下方式访问MemoryInfo.SizeInMiB：

  1. func main() {
  3.     // 创建一个会话
  4. 	sess := session.Must(session.NewSessionWithOptions(session.Options{
  5. 		SharedConfigState: session.SharedConfigEnable,
  6. 	}))
  8. 	ec2Svc := ec2.New(sess)
  9. 	params := &ec2.DescribeInstanceTypesInput{
  10. 		Filters: []*ec2.Filter{
  11. 			{
  12. 				Name:   aws.String("instance-type"),
  13. 				Values: []*string{aws.String("t2*")},
  14. 			},
  15. 		},
  16. 	}
  18.     // 使用NextToken循环检索实例类型。实例的过滤将在本地进行
  19. 	for {
  20. 		result, err := ec2Svc.DescribeInstanceTypes(params)
  21. 		if err != nil {
  22. 			fmt.Println("错误", err)
  23. 			break
  24. 		} else {
  25.             
  26.             // InstanceTypes是一个切片，所以我们需要遍历它
  27. 			for _, instance := range result.InstanceTypes {
  28. 				// 获取实例的内存大小
  29. 				fmt.Printf("%s - %d MiB\n", *instance.InstanceType, *instance.MemoryInfo.SizeInMiB)
  30. 			}
  32.             // 检查是否还有实例剩余
  33. 			if result.NextToken != nil {
  34. 				params.NextToken = result.NextToken
  35. 			} else {
  36. 				break
  37. 			}
  38. 		}
  39. 	}
  40. }

这应该会输出类似以下内容：

  1. t2.2xlarge - 32768 MiB
  2. t2.large - 8192 MiB
  3. t2.micro - 1024 MiB
  4. t2.medium - 4096 MiB
  5. t2.xlarge - 16384 MiB
  6. t2.small - 2048 MiB
  7. t2.nano - 512 MiB
英文:

You don't have to create a new structure, this is already provided by the SDK. The return type of DescribeInstanceTypes is a pointer to a DescribeInstanceTypesOutput object.

You can access MemoryInfo.SizeInMiB in the following way:

  1. func main() {
  3.     // Build a session
  4. 	sess := session.Must(session.NewSessionWithOptions(session.Options{
  5. 		SharedConfigState: session.SharedConfigEnable,
  6. 	}))
  8. 	ec2Svc := ec2.New(sess)
  9. 	params := &ec2.DescribeInstanceTypesInput{
  10. 		Filters: []*ec2.Filter{
  11. 			{
  12. 				Name:   aws.String("instance-type"),
  13. 				Values: []*string{aws.String("t2*")},
  14. 			},
  15. 		},
  16. 	}
  18.     // Retrieve the instance types in a loop using NextToken. The filtering of instances will happen locally
  19. 	for {
  20. 		result, err := ec2Svc.DescribeInstanceTypes(params)
  21. 		if err != nil {
  22. 			fmt.Println("Error", err)
  23. 			break
  24. 		} else {
  25.             
  26.             // InstanceTypes is slice, so we have to iterate over it
  27. 			for _, instance := range result.InstanceTypes {
  28. 				// Grab the memory size of the instance
  29. 				fmt.Printf("%s - %d MiB\n", *instance.InstanceType, *instance.MemoryInfo.SizeInMiB)
  30. 			}
  32.             // Check if they are any instances left
  33. 			if result.NextToken != nil {
  34. 				params.NextToken = result.NextToken
  35. 			} else {
  36. 				break
  37. 			}
  38. 		}
  39. 	}
  40. }

This should output something similar to this:

  1. t2.2xlarge - 32768 MiB
  2. t2.large - 8192 MiB
  3. t2.micro - 1024 MiB
  4. t2.medium - 4096 MiB
  5. t2.xlarge - 16384 MiB
  6. t2.small - 2048 MiB
  7. t2.nano - 512 MiB

huangapple
  • 本文由 发表于 2022年8月11日 18:38:02
  • 转载请务必保留本文链接：https://go.coder-hub.com/73319268.html
  • amazon-web-services
  • go
  • json
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