AWS CLI：如何扩展 aws ssm send-command 目标中的变量？

Question

我正在尝试构建一个 bash for 循环，将实例 ID 提供给以下 AWS CLI 命令以在多个实例上运行 Powershell。每当我尝试将 $server 的值扩展为变量 for 作为 for 循环中的实例 ID 列表时，我都会收到错误消息：

An error occurred (InvalidInstanceId) when calling the SendCommand operation:

在从启用了 AWS CLI 的 Linux 框中执行运行文档时，这里有一些尝试让 $server 正确扩展。当我用变量 $server 包含的相同实例 ID (i-081158da57d2a8da6) 替换 $server 或 ${server} 时，它可以正常工作。我觉得这一定非常简单，但我的研究技能让我无法弄清楚如何在我的 Linux 实例上从 AWS CLI 正确执行 SSM 文档所需的语法中扩展变量。

:~$ aws ssm send-command --document-name "AWS-RunPowerShellScript" --document-version "1" --targets '[{"Key":"InstanceIds","Values":["${server}"]}]' --parameters '{"commands":["$wmi = Get-WmiObject -Class Win32_OperatingSystem ","$uptimeMinutes = ($wmi.ConvertToDateTime($wmi.LocalDateTime)-$wmi.ConvertToDateTime($wmi.LastBootUpTime) | select-object -expandproperty "TotalMinutes")","[int]$uptimeMinutes"],"workingDirectory":[""],"executionTimeout":["60"]}' --timeout-seconds 600 --max-concurrency "50" --max-errors "0" --region us-west-2

An error occurred (InvalidInstanceId) when calling the SendCommand operation:

:~$ aws ssm send-command --document-name "AWS-RunPowerShellScript" --document-version "1" --targets '[{"Key":"InstanceIds","Values":["$server"]}]' --parameters '{"commands":["$wmi = Get-WmiObject -Class Win32_OperatingSystem ","$uptimeMinutes = ($wmi.ConvertToDateTime($wmi.LocalDateTime)-$wmi.ConvertToDateTime($wmi.LastBootUpTime) | select-object -expandproperty "TotalMinutes")","[int]$uptimeMinutes"],"workingDirectory":[""],"executionTimeout":["60"]}' --timeout-seconds 600 --max-concurrency "50" --max-errors "0" --region us-west-2

An error occurred (InvalidInstanceId) when calling the SendCommand operation:

Answer 1

JSON 文档用单引号括起来，这会关闭变量插值——请参阅 Difference between single and double quotes in Bash——这意味着 $server 不会展开。

效果演示如下：

[:~] $ server=banana
[:~] $ 
[:~] $ echo '[{"Key":"InstanceIds","Values":["$server"]}]'
[{"Key":"InstanceIds","Values":["$server"]}]
[:~] $

如果您改用双引号，值将被插入：

[:~] $ echo "[{\"Key\":\"InstanceIds\",\"Values\":[\"$server\"]}]"
[{"Key":"InstanceIds","Values":["banana"]}]
[:~] $

注意我必须在双引号内转义双引号。否则它们会从输出中消失，这将使其无效 JSON.

AWS CLI：如何扩展 aws ssm send-command 目标中的变量？

AWS CLI: How can you expand a variable in aws ssm send-command targets?

bash

amazon-ec2

aws-cli

aws-ssm