Restauración de un volumen raíz a partir de la última instantánea

El sistema operativo en un volumen raíz puede dañarse por varias razones. Por ejemplo, después de una operación de revisióno, las instancias podrían arrancar de manera incorrecta debido a un kernel o un registro dañado. La automatización de tareas comunes de solución de problemas, como la restauración de un volumen raíz a partir de la última instantánea tomada antes de la operación de aplicación de revisiones, puede reducir el tiempo de inactividad y agilizar los esfuerzos de solución de problemas. AWS Systems Manager Las acciones de Automation pueden ayudarlo a lograrlo. Automation es una capacidad de AWS Systems Manager.

El siguiente manual de procedimientos de AWS Systems Manager de ejemplo realiza estas acciones:

• Utiliza la acción de automatización aws:executeAwsApi para recuperar detalles del volumen raíz de la instancia.

• Utiliza la acción de automatización aws:executeScript para recuperar la última instantánea del volumen raíz.

• Utiliza la acción de automatización aws:branch para continuar la automatización si se encuentra una instantánea para el volumen raíz.

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"
                }
            }
        }
    }