Elastic Compute Service:Create a command

Create a command in the ECS console

1. Go to ECS console - ECS Cloud Assistant.

2. In the top navigation bar, select the region and resource group where you want to create the command.

   Selecting a resource group lets you manage command permissions at the resource group level using RAM policies. For details, see Cloud Assistant command-specific sample custom policies and Classify resources into resource groups and grant permissions on the resource groups.

   

3. In the upper-right corner of the ECS Cloud Assistant page, click Create/Run Command.

4. In the Command Information section of the Create Command panel, configure the following parameters. Command type Select the type that matches your target instance OS: Command content Enter or paste the command. Make sure the syntax, logic, and algorithm are correct before saving. Example — archive a file to /backup on a Linux instance:

   • Run at Fixed Interval: Specify an interval using a rate expression (60 seconds–7 days). The interval is the time between consecutive executions, not the execution duration. For example, if the interval is 5 minutes and a run takes 2 minutes, the next run starts 3 minutes after the previous run ends. The first run starts after the interval elapses from task creation. > Note: The interval must be longer than the command's timeout period.

   • Run Only Once at Specified Time: Set a specific date, time, and time zone. For example, May 17, 2022, 17:30:50 with (GMT+08:00) Asia/Shanghai runs the command once at that timestamp.

   • Run on Clock-based Schedule Cron Expression: Use a cron expression (accurate to seconds) and select a time zone. The minimum interval is 10 seconds and must exceed the timeout period. For example, 0 0 12 ? * WED 2022 with (GMT+08:00) Asia/Shanghai runs the command every Wednesday at 12:00:00 in 2022. For syntax details, see Cron expressions.

   Version requirements apply as follows: - `{{ACS::InstanceId}}` and `{{ACS::InstanceName}}`: When running a command on multiple instances, make sure the Cloud Assistant Agent on each instance meets the minimum version listed above. - `{{ACS::InvokeId}}`: Make sure the Cloud Assistant Agent version meets the minimum version listed above. - `{{ACS::CommandId}}`: When calling the RunCommand API, make sure the Cloud Assistant Agent version meets the minimum version listed above. To upgrade, see Install Cloud Assistant Agent.

   Command source

   Option	Description
   Enter Command Content	Write a new command.
   Select Saved Command	Use an existing saved command.

   Parameter	Description	Minimum Cloud Assistant Agent version
   {{ACS::RegionId}}	Region ID	—
   {{ACS::AccountId}}	Alibaba Cloud account UID	—
   {{ACS::InstanceId}}	Instance ID	Linux >= 2.2.3.309, Windows >= 2.1.3.309
   {{ACS::InstanceName}}	Instance name	Linux >= 2.2.3.344, Windows >= 2.1.3.344
   {{ACS::InvokeId}}	Command task ID	Linux >= 2.2.3.309, Windows >= 2.1.3.309
   {{ACS::CommandId}}	Command ID	Linux >= 2.2.3.309, Windows >= 2.1.3.309

   Execution plan

   Option	Behavior
   Immediate execution	Runs as soon as you click Run or Run and Save.
   After the next startup of the system	Runs the next time the associated instances start.
   After each system startup	Runs every time the associated instances start.
   Run on Schedule	Runs on a defined schedule. See schedule options below.

   Other parameters

   Parameter	Description
   Command Name	A name for the command.
   Command Description	A description. Include the purpose of the command to simplify future management.
   Username	The OS user that runs the command on instances. Default: root on Linux, system on Windows. Run commands as a user with the minimum required privileges. See Run Cloud Assistant commands as a regular user.
   Execution Path	The directory in which to run the command. Default: /home (Linux root user home directory) or C:\Windows\system32 (Windows).
   Timeout	Maximum time allowed for the command to run, in seconds. Default: 60. Minimum: 10. Values below 10 are automatically set to 10.
   Tag	A tag (key-value pair) to classify and manage the command. If you click Run and Save, the tag is applied to both the command and the execution task. If you click Run, the tag is applied to the command only.

   #!/bin/bash
   OF=/backup/my-backup-$(date +%Y%m%d).tgz
   tar -cf $OF {{file}}

   In this example, {{file}} is a custom parameter. Set it to the file path at runtime (for example, /app/usrcredential). For more information, see View the system configurations of ECS instances. Use parameters Turn on Use Parameters to define custom parameters in the {{key}} format in your command content. You can specify up to 20 custom parameters per command. Cloud Assistant also provides built-in environment parameters that are resolved automatically at runtime: Run on Schedule options:

5. In the Select Instance and Select Managed Instances sections, select the instances on which to run the command.

   A managed instance is a non-ECS server managed by Cloud Assistant. For details, see Alibaba Cloud managed instances.

6. Click Save.

Create a command using Alibaba Cloud CLI

Call the CreateCommand API to create a command. The following example creates a command named update that updates the operating system on Linux instances.

aliyun ecs CreateCommand --RegionId 'cn-hangzhou' \
--CommandContent 'eXVtIHVwZGF0ZSAteQ==' \
--Type 'RunShellScript' \
--Name 'update' \
--Description 'update' \
--output cols=CommandId

The values in single quotes are examples. Replace them with your actual values.

Key parameters:

For the full parameter reference, see CreateCommand.

Sample response:

CommandId
---------
c-hz018qng4on****