最新のスナップショットからルートボリュームを復元する

ルートボリューム上のオペレーティングシステムは、さまざまな理由で破損する可能性があります。例えば、パッチ適用オペレーション後、カーネルまたはレジストリが破損しているため、インスタンスが正常に起動しない場合があります。パッチ適用操作の前に作成された最新のスナップショットからルートボリュームを復元するなどの一般的なトラブルシューティングタスクを自動化することで、ダウンタイムを短縮し、トラブルシューティング作業を迅速化できます。AWS Systems Managerオートメーションアクションが、これを実現するのに役立ちます。オートメーションは の一機能ですAWS Systems Manager

次の AWS Systems Manager ランブックの例では、これらのアクションを実行します。

• aws:executeAwsApi オートメーションアクションを使用して、インスタンスのルートボリュームから詳細を取得します。

• aws:executeScript オートメーションアクションを使用して、ルートボリュームの最新のスナップショットを取得します。

• ルートボリュームのスナップショットが見つかった場合、aws:branch オートメーションアクションを使用して実行を続行します。

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"
                }
            }
        }
    }