Working with parameters using Run Command commands - AWS Systems Manager

Working with parameters using Run Command commands

You can work with parameters in Run Command, a capability of AWS Systems Manager. For more information, see Sending commands using Systems Manager Run Command.

Run a String parameter (console)

The following procedure walks you through the process of running a command that uses a String parameter.

To run a String parameter using Parameter Store

  1. Open the AWS Systems Manager console at https://console.aws.amazon.com/systems-manager/.

  2. In the navigation pane, choose Run Command.

    -or-

    If the AWS Systems Manager home page opens first, choose the menu icon ( ) to open the navigation pane, and then choose Run Command.

  3. Choose Run command.

  4. In the Command document list, choose AWS-RunPowerShellScript (Windows) or AWS-RunShellScript (Linux).

  5. For Command parameters, enter echo {{ssm:parameter-name}}. For example: echo {{ssm:/Test/helloWorld}}.

  6. In the Targets section, choose the managed nodes on which you want to run this operation by specifying tags, selecting instances or edge devices manually, or specifying a resource group.

    Note

    If a managed node you expect to see isn't listed, see Troubleshooting managed node availability for troubleshooting tips.

  7. For Other parameters:

    • For Comment, enter information about this command.

    • For Timeout (seconds), specify the number of seconds for the system to wait before failing the overall command execution.

  8. For Rate control:

    • For Concurrency, specify either a number or a percentage of managed nodes on which to run the command at the same time.

      Note

      If you selected targets by specifying tags applied to managed nodes or by specifying AWS resource groups, and you aren't certain how many managed nodes are targeted, then restrict the number of targets that can run the document at the same time by specifying a percentage.

    • For Error threshold, specify when to stop running the command on other managed nodes after it fails on either a number or a percentage of nodes. For example, if you specify three errors, then Systems Manager stops sending the command when the fourth error is received. Managed nodes still processing the command might also send errors.

  9. (Optional) For Output options, to save the command output to a file, select the Write command output to an S3 bucket box. Enter the bucket and prefix (folder) names in the boxes.

    Note

    The S3 permissions that grant the ability to write the data to an S3 bucket are those of the instance profile (for EC2 instances) or IAM service role (on-premises machines) assigned to the instance, not those of the IAM user performing this task. For more information, see Create an IAM instance profile for Systems Manager or Create an IAM service role for a hybrid environment. In addition, if the specified S3 bucket is in a different AWS account, make sure that the instance profile or IAM service role associated with the managed node has the necessary permissions to write to that bucket.

  10. In the SNS notifications section, if you want notifications sent about the status of the command execution, select the Enable SNS notifications check box.

    For more information about configuring Amazon SNS notifications for Run Command, see Monitoring Systems Manager status changes using Amazon SNS notifications.

  11. Choose Run.

  12. In the Command ID page, in the Targets and outputs area, select the button next to the ID of a node where you ran the command, and then choose View output. Verify that the output of the command is the value you provided for the parameter, such as This is my first parameter.

Run a parameter (AWS CLI)

The following example command includes a Systems Manager parameter named DNS-IP. The value of this parameter is simply the IP address of a node. This example uses an AWS Command Line Interface (AWS CLI) command to echo the parameter value.

Linux & macOS
aws ssm send-command \ --document-name "AWS-RunShellScript" \ --document-version "1" \ --targets "Key=instanceids,Values=i-02573cafcfEXAMPLE" \ --parameters "commands='echo {{ssm:DNS-IP}}'" \ --timeout-seconds 600 \ --max-concurrency "50" \ --max-errors "0" \ --region us-east-2
Windows
aws ssm send-command ^ --document-name "AWS-RunPowerShellScript" ^ --document-version "1" ^ --targets "Key=instanceids,Values=i-02573cafcfEXAMPLE" ^ --parameters "commands='echo {{ssm:DNS-IP}}'" ^ --timeout-seconds 600 ^ --max-concurrency "50" ^ --max-errors "0" ^ --region us-east-2

The next example command uses a SecureString parameter named SecurePassword. The command used in the parameters field retrieves and decrypts the value of the SecureString parameter, and then resets the local administrator password without having to pass the password in clear text.

Linux
aws ssm send-command \ --document-name "AWS-RunShellScript" \ --document-version "1" \ --targets "Key=instanceids,Values=i-02573cafcfEXAMPLE" \ --parameters '{"commands":["secure=$(aws ssm get-parameters --names SecurePassword --with-decryption --query Parameters[0].Value --output text --region us-east-2)","echo $secure | passwd myuser --stdin"]}' \ --timeout-seconds 600 \ --max-concurrency "50" \ --max-errors "0" \ --region us-east-2
Windows
aws ssm send-command ^ --document-name "AWS-RunPowerShellScript" ^ --document-version "1" ^ --targets "Key=instanceids,Values=i-02573cafcfEXAMPLE" ^ --parameters "commands=['$secure = (Get-SSMParameterValue -Names SecurePassword -WithDecryption $True).Parameters[0].Value','net user administrator $secure']" ^ --timeout-seconds 600 ^ --max-concurrency "50" ^ --max-errors "0" ^ --region us-east-2

You can also reference Systems Manager parameters in the Parameters section of an SSM document, as shown in the following example.

{ "schemaVersion":"2.0", "description":"Sample version 2.0 document v2", "parameters":{ "commands" : { "type": "StringList", "default": ["{{ssm:parameter-name}}"] } }, "mainSteps":[ { "action":"aws:runShellScript", "name":"runShellScript", "inputs":{ "runCommand": "{{commands}}" } } ] }

Don't confuse the similar syntax for local parameters used in the runtimeConfig section of SSM documents with Parameter Store parameters. A local parameter isn't the same as a Systems Manager parameter. You can distinguish local parameters from Systems Manager parameters by the absence of the ssm: prefix.

"runtimeConfig":{ "aws:runShellScript":{ "properties":[ { "id":"0.aws:runShellScript", "runCommand":"{{ commands }}", "workingDirectory":"{{ workingDirectory }}", "timeoutSeconds":"{{ executionTimeout }}"
Note

SSM documents don't support references to SecureString parameters. This means that to use SecureString parameters with, for example, Run Command, you have to retrieve the parameter value before passing it to Run Command, as shown in the following examples.

Linux & macOS
value=$(aws ssm get-parameters --names parameter-name --with-decryption)
aws ssm send-command \ --name AWS-JoinDomain \ --parameters password=$value \ --instance-id instance-id
Windows
aws ssm send-command ^ --name AWS-JoinDomain ^ --parameters password=$value ^ --instance-id instance-id
Powershell
$secure = (Get-SSMParameterValue -Names parameter-name -WithDecryption $True).Parameters[0].Value | ConvertTo-SecureString -AsPlainText -Force
$cred = New-Object System.Management.Automation.PSCredential -argumentlist user-name,$secure