從最新的快照還原根磁碟區

根磁碟區上的作業系統可能會因各種原因而損毀。例如，在修補操作之後，執行個體可能會因為核心損毀或登錄而無法成功啟動。自動化常見的故障診斷任務 (例如從修補操作前的最新快照還原根磁碟區)，可以減少停機時間並加速您的故障診斷工作。AWS Systems Manager自動化動作可以協助您達成此目標。自動化是 AWS Systems Manager 的功能。

下列範例 AWS Systems Manager 執行手冊會執行這些動作：

• 使用 aws:executeAwsApi 自動化動作從執行個體的根磁碟區擷取詳細資訊。

• 使用 aws:executeScript 自動化動作來擷取根磁碟區的最新快照。

• 如果找到了根磁碟區的快照，請使用 aws:branch 自動化動作來繼續自動化。

YAML

    ---
    description: Custom Automation Troubleshooting Example
    schemaVersion: '0.3'
    assumeRole: "{{ AutomationAssumeRole }}"
    parameters:
      AutomationAssumeRole:
        type: String
        description: "(Required) The ARN of the role that allows Automation to perform
          the actions on your behalf. If no role is specified, Systems Manager Automation
          uses your IAM permissions to use this runbook."
        default: ''
      InstanceId:
          type: String
          description: "(Required) The Instance Id whose root EBS volume you want to restore the latest Snapshot."
          default: ''
    mainSteps:
    - name: getInstanceDetails
      action: aws:executeAwsApi
      onFailure: Abort
      inputs:
        Service: ec2
        Api: DescribeInstances
        InstanceIds:
        - "{{ InstanceId }}"
      outputs:
        - Name: availabilityZone
          Selector: "$.Reservations[0].Instances[0].Placement.AvailabilityZone"
          Type: String
        - Name: rootDeviceName
          Selector: "$.Reservations[0].Instances[0].RootDeviceName"
          Type: String
      nextStep: getRootVolumeId
    - name: getRootVolumeId
      action: aws:executeAwsApi
      onFailure: Abort
      inputs:
        Service: ec2
        Api: DescribeVolumes
        Filters:
        -  Name: attachment.device
           Values: ["{{ getInstanceDetails.rootDeviceName }}"]
        -  Name: attachment.instance-id
           Values: ["{{ InstanceId }}"]
      outputs:
        - Name: rootVolumeId
          Selector: "$.Volumes[0].VolumeId"
          Type: String
      nextStep: getSnapshotsByStartTime
    - name: getSnapshotsByStartTime
      action: aws:executeScript
      timeoutSeconds: 45
      onFailure: Abort
      inputs:
        Runtime: python3.8
        Handler: getSnapshotsByStartTime
        InputPayload:
          rootVolumeId : "{{ getRootVolumeId.rootVolumeId }}"
        Script: |-
          def getSnapshotsByStartTime(events,context):
            import boto3
    
            #Initialize client
            ec2 = boto3.client('ec2')
            rootVolumeId = events['rootVolumeId']
            snapshotsQuery = ec2.describe_snapshots(
              Filters=[
                {
                  "Name": "volume-id",
                  "Values": [rootVolumeId]
                }
              ]
            )
            if not snapshotsQuery['Snapshots']:
              noSnapshotFoundString = "NoSnapshotFound"
              return { 'noSnapshotFound' : noSnapshotFoundString }
            else:
              jsonSnapshots = snapshotsQuery['Snapshots']
              sortedSnapshots = sorted(jsonSnapshots, key=lambda k: k['StartTime'], reverse=True)
              latestSortedSnapshotId = sortedSnapshots[0]['SnapshotId']
              return { 'latestSnapshotId' : latestSortedSnapshotId }
      outputs:
      - Name: Payload
        Selector: $.Payload
        Type: StringMap
      - Name: latestSnapshotId
        Selector: $.Payload.latestSnapshotId
        Type: String
      - Name: noSnapshotFound
        Selector: $.Payload.noSnapshotFound
        Type: String 
      nextStep: branchFromResults
    - name: branchFromResults
      action: aws:branch
      onFailure: Abort
      inputs:
        Choices:
        - NextStep: createNewRootVolumeFromSnapshot
          Not:
            Variable: "{{ getSnapshotsByStartTime.noSnapshotFound }}"
            StringEquals: "NoSnapshotFound"
      isEnd: true
    - name: createNewRootVolumeFromSnapshot
      action: aws:executeAwsApi
      onFailure: Abort
      inputs:
        Service: ec2
        Api: CreateVolume
        AvailabilityZone: "{{ getInstanceDetails.availabilityZone }}"
        SnapshotId: "{{ getSnapshotsByStartTime.latestSnapshotId }}"
      outputs:
        - Name: newRootVolumeId
          Selector: "$.VolumeId"
          Type: String
      nextStep: stopInstance
    - name: stopInstance
      action: aws:executeAwsApi
      onFailure: Abort
      inputs:
        Service: ec2
        Api: StopInstances
        InstanceIds:
        - "{{ InstanceId }}"
      nextStep: verifyVolumeAvailability
    - name: verifyVolumeAvailability
      action: aws:waitForAwsResourceProperty
      timeoutSeconds: 120
      inputs:
        Service: ec2
        Api: DescribeVolumes
        VolumeIds:
        - "{{ createNewRootVolumeFromSnapshot.newRootVolumeId }}"
        PropertySelector: "$.Volumes[0].State"
        DesiredValues:
        - "available"
      nextStep: verifyInstanceStopped
    - name: verifyInstanceStopped
      action: aws:waitForAwsResourceProperty
      timeoutSeconds: 120
      inputs:
        Service: ec2
        Api: DescribeInstances
        InstanceIds:
        - "{{ InstanceId }}"
        PropertySelector: "$.Reservations[0].Instances[0].State.Name"
        DesiredValues:
        - "stopped"
      nextStep: detachRootVolume
    - name: detachRootVolume
      action: aws:executeAwsApi
      onFailure: Abort
      inputs:
        Service: ec2
        Api: DetachVolume
        VolumeId: "{{ getRootVolumeId.rootVolumeId }}"
      nextStep: verifyRootVolumeDetached
    - name: verifyRootVolumeDetached
      action: aws:waitForAwsResourceProperty
      timeoutSeconds: 30
      inputs:
        Service: ec2
        Api: DescribeVolumes
        VolumeIds:
        - "{{ getRootVolumeId.rootVolumeId }}"
        PropertySelector: "$.Volumes[0].State"
        DesiredValues:
        - "available"
      nextStep: attachNewRootVolume
    - name: attachNewRootVolume
      action: aws:executeAwsApi
      onFailure: Abort
      inputs:
        Service: ec2
        Api: AttachVolume
        Device: "{{ getInstanceDetails.rootDeviceName }}"
        InstanceId: "{{ InstanceId }}"
        VolumeId: "{{ createNewRootVolumeFromSnapshot.newRootVolumeId }}"
      nextStep: verifyNewRootVolumeAttached
    - name: verifyNewRootVolumeAttached
      action: aws:waitForAwsResourceProperty
      timeoutSeconds: 30
      inputs:
        Service: ec2
        Api: DescribeVolumes
        VolumeIds:
        - "{{ createNewRootVolumeFromSnapshot.newRootVolumeId }}"
        PropertySelector: "$.Volumes[0].Attachments[0].State"
        DesiredValues:
        - "attached"
      nextStep: startInstance
    - name: startInstance
      action: aws:executeAwsApi
      onFailure: Abort
      inputs:
        Service: ec2
        Api: StartInstances
        InstanceIds:
        - "{{ InstanceId }}"

JSON

    {
       "description": "Custom Automation Troubleshooting Example",
       "schemaVersion": "0.3",
       "assumeRole": "{{ AutomationAssumeRole }}",
       "parameters": {
          "AutomationAssumeRole": {
             "type": "String",
             "description": "(Required) The ARN of the role that allows Automation to perform the actions on your behalf. If no role is specified, Systems Manager Automation uses your IAM permissions to run this runbook.",
             "default": ""
          },
          "InstanceId": {
             "type": "String",
             "description": "(Required) The Instance Id whose root EBS volume you want to restore the latest Snapshot.",
             "default": ""
          }
       },
       "mainSteps": [
          {
             "name": "getInstanceDetails",
             "action": "aws:executeAwsApi",
             "onFailure": "Abort",
             "inputs": {
                "Service": "ec2",
                "Api": "DescribeInstances",
                "InstanceIds": [
                   "{{ InstanceId }}"
                ]
             },
             "outputs": [
                {
                   "Name": "availabilityZone",
                   "Selector": "$.Reservations[0].Instances[0].Placement.AvailabilityZone",
                   "Type": "String"
                },
                {
                   "Name": "rootDeviceName",
                   "Selector": "$.Reservations[0].Instances[0].RootDeviceName",
                   "Type": "String"
                }
             ],
             "nextStep": "getRootVolumeId"
          },
          {
             "name": "getRootVolumeId",
             "action": "aws:executeAwsApi",
             "onFailure": "Abort",
             "inputs": {
                "Service": "ec2",
                "Api": "DescribeVolumes",
                "Filters": [
                   {
                      "Name": "attachment.device",
                      "Values": [
                         "{{ getInstanceDetails.rootDeviceName }}"
                      ]
                   },
                   {
                      "Name": "attachment.instance-id",
                      "Values": [
                         "{{ InstanceId }}"
                      ]
                   }
                ]
             },
             "outputs": [
                {
                   "Name": "rootVolumeId",
                   "Selector": "$.Volumes[0].VolumeId",
                   "Type": "String"
                }
             ],
             "nextStep": "getSnapshotsByStartTime"
          },
          {
             "name": "getSnapshotsByStartTime",
             "action": "aws:executeScript",
             "timeoutSeconds": 45,
             "onFailure": "Continue",
             "inputs": {
                "Runtime": "python3.8",
                "Handler": "getSnapshotsByStartTime",
                "InputPayload": {
                   "rootVolumeId": "{{ getRootVolumeId.rootVolumeId }}"
                },
                "Attachment": "getSnapshotsByStartTime.py"
             },
             "outputs": [
                {
                   "Name": "Payload",
                   "Selector": "$.Payload",
                   "Type": "StringMap"
                },
                {
                   "Name": "latestSnapshotId",
                   "Selector": "$.Payload.latestSnapshotId",
                   "Type": "String"
                },
                {
                   "Name": "noSnapshotFound",
                   "Selector": "$.Payload.noSnapshotFound",
                   "Type": "String"
                }
             ],
             "nextStep": "branchFromResults"
          },
          {
             "name": "branchFromResults",
             "action": "aws:branch",
             "onFailure": "Abort",
             "inputs": {
                "Choices": [
                   {
                      "NextStep": "createNewRootVolumeFromSnapshot",
                      "Not": {
                         "Variable": "{{ getSnapshotsByStartTime.noSnapshotFound }}",
                         "StringEquals": "NoSnapshotFound"
                      }
                   }
                ]
             },
             "isEnd": true
          },
          {
             "name": "createNewRootVolumeFromSnapshot",
             "action": "aws:executeAwsApi",
             "onFailure": "Abort",
             "inputs": {
                "Service": "ec2",
                "Api": "CreateVolume",
                "AvailabilityZone": "{{ getInstanceDetails.availabilityZone }}",
                "SnapshotId": "{{ getSnapshotsByStartTime.latestSnapshotId }}"
             },
             "outputs": [
                {
                   "Name": "newRootVolumeId",
                   "Selector": "$.VolumeId",
                   "Type": "String"
                }
             ],
             "nextStep": "stopInstance"
          },
          {
             "name": "stopInstance",
             "action": "aws:executeAwsApi",
             "onFailure": "Abort",
             "inputs": {
                "Service": "ec2",
                "Api": "StopInstances",
                "InstanceIds": [
                   "{{ InstanceId }}"
                ]
             },
             "nextStep": "verifyVolumeAvailability"
          },
          {
             "name": "verifyVolumeAvailability",
             "action": "aws:waitForAwsResourceProperty",
             "timeoutSeconds": 120,
             "inputs": {
                "Service": "ec2",
                "Api": "DescribeVolumes",
                "VolumeIds": [
                   "{{ createNewRootVolumeFromSnapshot.newRootVolumeId }}"
                ],
                "PropertySelector": "$.Volumes[0].State",
                "DesiredValues": [
                   "available"
                ]
             },
             "nextStep": "verifyInstanceStopped"
          },
          {
             "name": "verifyInstanceStopped",
             "action": "aws:waitForAwsResourceProperty",
             "timeoutSeconds": 120,
             "inputs": {
                "Service": "ec2",
                "Api": "DescribeInstances",
                "InstanceIds": [
                   "{{ InstanceId }}"
                ],
                "PropertySelector": "$.Reservations[0].Instances[0].State.Name",
                "DesiredValues": [
                   "stopped"
                ]
             },
             "nextStep": "detachRootVolume"
          },
          {
             "name": "detachRootVolume",
             "action": "aws:executeAwsApi",
             "onFailure": "Abort",
             "inputs": {
                "Service": "ec2",
                "Api": "DetachVolume",
                "VolumeId": "{{ getRootVolumeId.rootVolumeId }}"
             },
             "nextStep": "verifyRootVolumeDetached"
          },
          {
             "name": "verifyRootVolumeDetached",
             "action": "aws:waitForAwsResourceProperty",
             "timeoutSeconds": 30,
             "inputs": {
                "Service": "ec2",
                "Api": "DescribeVolumes",
                "VolumeIds": [
                   "{{ getRootVolumeId.rootVolumeId }}"
                ],
                "PropertySelector": "$.Volumes[0].State",
                "DesiredValues": [
                   "available"
                ]
             },
             "nextStep": "attachNewRootVolume"
          },
          {
             "name": "attachNewRootVolume",
             "action": "aws:executeAwsApi",
             "onFailure": "Abort",
             "inputs": {
                "Service": "ec2",
                "Api": "AttachVolume",
                "Device": "{{ getInstanceDetails.rootDeviceName }}",
                "InstanceId": "{{ InstanceId }}",
                "VolumeId": "{{ createNewRootVolumeFromSnapshot.newRootVolumeId }}"
             },
             "nextStep": "verifyNewRootVolumeAttached"
          },
          {
             "name": "verifyNewRootVolumeAttached",
             "action": "aws:waitForAwsResourceProperty",
             "timeoutSeconds": 30,
             "inputs": {
                "Service": "ec2",
                "Api": "DescribeVolumes",
                "VolumeIds": [
                   "{{ createNewRootVolumeFromSnapshot.newRootVolumeId }}"
                ],
                "PropertySelector": "$.Volumes[0].Attachments[0].State",
                "DesiredValues": [
                   "attached"
                ]
             },
             "nextStep": "startInstance"
          },
          {
             "name": "startInstance",
             "action": "aws:executeAwsApi",
             "onFailure": "Abort",
             "inputs": {
                "Service": "ec2",
                "Api": "StartInstances",
                "InstanceIds": [
                   "{{ InstanceId }}"
                ]
             }
          }
       ],
       "files": {
            "getSnapshotsByStartTime.py": {
                "checksums": {
                    "sha256": "sampleETagValue"
                }
            }
        }
    }