AWS Java SDK - Running a command using SSM on EC2 instances - amazon-web-services

Question

I could not find any examples of this online, nor could I find the documentation explaining how to do this. Basically I have a list of Windows EC2 instances and I need to run the quser command in each one of them to check how many users are logged on.
It is possible to do this using the AWS Systems Manager service and running the AWS-RunPowerShellScript command. I only found examples using the AWS CLI, something like this:
aws ssm send-command --instance-ids "instance ID" --document-name "AWS-RunPowerShellScript" --comment "Get Users" --parameters commands=quser --output text
But how can I accomplish this using the AWS Java SDK 1.11.x ?

Answer 1

#Alexandre Krabbe it's more than a year before you asked this question. So not sure the answer will help you. But I was trying to do the same recently and that led me to this unanswered question. I ended up solving the problem and thought my answer could help other people facing the same problem. Here is a code snippet for the same:
public void runCommand() throws InterruptedException {
//Command to be run
String ssmCommand = "ls -l";
Map<String, List<String>> params = new HashMap<String, List<String>>(){{
put("commands", new ArrayList<String>(){{ add(ssmCommand); }});
}};
int timeoutInSecs = 5;
//You can add multiple command ids separated by commas
Target target = new Target().withKey("InstanceIds").withValues("instance-id");
//Create ssm client.
//The builder could be chosen as per your preferred way of authentication
//use withRegion for specifying your region
AWSSimpleSystemsManagement ssm = AWSSimpleSystemsManagementClientBuilder.standard().build();
//Build a send command request
SendCommandRequest commandRequest = new SendCommandRequest()
.withTargets(target)
.withDocumentName("AWS-RunShellScript")
.withParameters(params);
//The result has commandId which is used to track the execution further
SendCommandResult commandResult = ssm.sendCommand(commandRequest);
String commandId = commandResult.getCommand().getCommandId();
//Loop until the invocation ends
String status;
do {
ListCommandInvocationsRequest request = new ListCommandInvocationsRequest()
.withCommandId(commandId)
.withDetails(true);
//You get one invocation per ec2 instance that you added to target
//For just a single instance use get(0) else loop over the instanced
CommandInvocation invocation = ssm.listCommandInvocations(request).getCommandInvocations().get(0);
status = invocation.getStatus();
if(status.equals("Success")) {
//command output holds the output of running the command
//eg. list of directories in case of ls
String commandOutput = invocation.getCommandPlugins().get(0).getOutput();
//Process the output
}
//Wait for a few seconds before you check the invocation status again
try {
TimeUnit.SECONDS.sleep(timeoutInSecs);
} catch (InterruptedException e) {
//Handle not being able to sleep
}
} while(status.equals("Pending") || status.equals("InProgress"));
if(!status.equals("Success")) {
//Command ended up in a failure
}
}

Answer 2

In SDK 1.11.x , use sth like:
val waiter = ssmClient.waiters().commandExecuted()
waiter.run(WaiterParameters(GetCommandInvocationRequest()
.withCommandId(commandId)
.withInstanceId(instanceId)
))