Auto Scaling:Mount a NAS file system to an ECS instance

Procedure

This tutorial uses the public OOS template ACS-ESS-LifeCycleAttachNASFileSystemToInstance as an example to show how to automatically mount a NAS file system to a Linux ECS instance during a scale-out event. The procedure is as follows:

Step 1: Grant OOS service permissions to the RAM role

You must have the required permissions to execute OOS templates. The operations and maintenance (O&M) operations defined in the ACS-ESS-LifeCycleAttachNASFileSystemToInstance template involve resources from Elastic Compute Service (ECS), Auto Scaling, and NAS.

1. Log on to the Resource Access Management (RAM) console.

2. Create an access policy.

   1. In the navigation pane on the left, click Permission Management > Access Policies.

   2. Click Create Access Policy.

   3. On the Create Policy page, select Script Editor as the configuration mode, set the other parameters, and then click OK.

      The following table describes the parameters used in this tutorial. Keep the default values for other parameters.

      Configuration item	Description
      Name	Enter ESSHookPolicyForAttachNAS.
      Policy Document	Enter the following content: { "Version": "1", "Statement": [ { "Action": [ "ecs:DescribeInvocations", "ecs:RunCommand", "ecs:DescribeInvocationResults", "ecs:DescribeInstances" ], "Resource": "*", "Effect": "Allow" }, { "Action": [ "ess:CompleteLifecycleAction" ], "Resource": "*", "Effect": "Allow" } ] }

3. Grant the access policy to OOSServiceRole.

   1. In the navigation pane on the left, click Identity Management > Roles.

   2. Find OOSServiceRole and click Add Permissions in the Actions column.

      Grant the required permissions to the OOSServiceRole RAM role.

   3. On the Grant Permission page, specify the resource scope and permission configuration, and then click Confirm Add Authorization.

      The following table describes the parameters used in this tutorial. Keep the default values for other parameters.

      Configuration item	Description
      Resource Scope	Select the Account level.
      Policies	Add the custom policy ESSHookPolicyForAttachNAS.

Step 2: Create a lifecycle hook for scale-out activities and trigger a scale-out

1. Log on to the Auto Scaling console.

2. In the navigation pane on the left, click Scaling Groups.

3. In the top navigation bar, select a region.

4. Find the scaling group that you want to manage and open its details page in one of the following ways:

   • In the Scaling Group Name/ID column, click the ID of the scaling group.

   • In the Actions column, click Details.

5. Create a lifecycle hook for scale-out activities.

   1. At the top of the page, click the Event and adhesive hook tab.

   2. Click Create Lifecycle Hook.

   3. Specify the lifecycle hook configuration and click OK.

      The following table describes the parameters used in this tutorial. Keep the default values for other parameters.

      Configuration item	Description
      Name	Enter ESSHookForAttachNAS.
      Scaling Activity Type	Select Scale-Out.
      Timeout Period	Enter an appropriate timeout period, such as 300 seconds. Note The timeout period is the time allowed for custom operations. If the timeout period is too short, the custom operations may fail. Evaluate the time required for your custom operations and set an appropriate timeout period.
      Default Execution Policy	Select Continue.
      Send Notification When Lifecycle Hook Takes Effect	Send notifications or automatically perform more operations in a specified way. The template settings are as follows: Notification method: Select OOS Template. OOS Template Type: Select Public Templates. Public Template: Select ACS-ESS-LifeCycleAttachNASFileSystemToInstance. The execution parameters for ACS-ESS-LifeCycleAttachNASFileSystemToInstance are configured as follows: Mount Target Domain Name: Enter the mount target domain name of the NAS file system. Mount Directory: The directory on the ECS instance where the file system is mounted, which defaults to /mnt. File System Version: 0 indicates that the NFS v4 protocol is used to mount the file system, and 1 indicates that the NFS v3 protocol is used. In this example, 0 is used. Rate Control: Two types of rate control are available: Concurrency Control and Batch Control. This tutorial uses the default type, Concurrency Control, as an example. RAM Role For OOS: Select Specify RAM Role and Use Permissions Granted to This Role, and then select OOSServiceRole. In the Procedure, the OOSServiceRole RAM role is granted permissions to manage ECS, Auto Scaling, and NAS file system resources. The OOS service assumes this role to obtain the required permissions.

6. Trigger a scale-out.

   This tutorial uses manual execution of a scaling rule as an example. You can also trigger a scale-out using a scheduled task or an event-triggered task.

   Note

   Lifecycle hooks take effect when you manually execute a scaling rule to trigger a scaling activity. However, lifecycle hooks do not take effect when you manually add or remove ECS instances.

   1. At the top of the page, click the Scaling Rules and Event-triggered Tasks tab.

   2. On the Scaling Rules tab, click Create Scaling Rule.

   3. Set the properties of the scaling rule, and then click OK.

      The following table describes the parameters used in this tutorial. Keep the default values for other parameters.

      Configuration item	Description
      Rule Name	Enter Add1.
      Rule Type	Select Simple Scaling Rule.
      Operation	Set to add 1 instance.

   4. In the list of scaling rules, find the newly created scaling rule Add1, and in the Actions column, click Recurrently.

   5. Click OK.

   After the scaling rule is executed, one ECS instance is automatically created. Because the ESSHookForAttachNAS lifecycle hook is created in the scaling group, the ECS instance is suspended. The OOS service is automatically notified to perform the O&M operations defined in the ACS-ESS-LifeCycleAttachNASFileSystemToInstance template.

7. Check if the automatically created ECS instance works as expected.

   1. At the top of the page, click the Instance Management tab.

   2. Find the automatically created ECS instance, and in the ECS Instance ID/Name column, click the instance ID.

   3. In the Basic Information area, click Remote Connection.

   4. After you log on to the ECS instance, run a command to check the mount result.

      df -h | grep aliyun

      As shown in the following figure, the result contains the mount path of the NAS file system. This indicates that the automatic mount is successful. You can also run nfsstat -c to view the protocol version used. Client nfs v4 indicates that the protocol version is v4.

      If an ECS instance is created but the NAS file system is not mounted, you can go to the OOS console to view the task execution status. For more information, see (Optional) Step 3: View the OOS execution status.

(Optional) Step 3: View the OOS execution status

1. Log on to the OOS console.

2. In the navigation pane on the left, choose Automated Tasks > Task Execution Management.

3. Find the execution based on the start time and click Details in the Actions column.

4. On the execution details page, view the execution information.

   For example, you can view information such as the execution ID and execution status in the Basic Information section, or click a task node in the Execution Result section to view the execution details. For more information, see View task execution details.

   Note

   If the execution fails, the related error message is also displayed on the execution details page.

FAQ