Use StartInstances with an AWS SDK or CLI

    /// <summary>
    /// Start an EC2 instance.
    /// </summary>
    /// <param name="ec2InstanceId">The instance Id of the Amazon EC2 instance
    /// to start.</param>
    /// <returns>Async task.</returns>
    public async Task StartInstances(string ec2InstanceId)
    {
        try
        {
            var request = new StartInstancesRequest
            {
                InstanceIds = new List<string> { ec2InstanceId },
            };

            await _amazonEC2.StartInstancesAsync(request);

            Console.Write("Waiting for instance to start. ");
            await WaitForInstanceState(ec2InstanceId, InstanceStateName.Running);
        }
        catch (AmazonEC2Exception ec2Exception)
        {
            if (ec2Exception.ErrorCode == "InvalidInstanceId")
            {
                _logger.LogError(
                    $"InstanceId is invalid, unable to start. {ec2Exception.Message}");
            }

            throw;
        }
        catch (Exception ex)
        {
            _logger.LogError(
                $"An error occurred while starting the instance.: {ex.Message}");
            throw;
        }
    }

    /// <summary>
    /// Wait until an EC2 instance is in a specified state.
    /// </summary>
    /// <param name="instanceId">The instance Id.</param>
    /// <param name="stateName">The state to wait for.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> WaitForInstanceState(string instanceId, InstanceStateName stateName)
    {
        var request = new DescribeInstancesRequest
        {
            InstanceIds = new List<string> { instanceId }
        };

        // Wait until the instance is in the specified state.
        var hasState = false;
        do
        {
            // Wait 5 seconds.
            Thread.Sleep(5000);

            // Check for the desired state.
            var response = await _amazonEC2.DescribeInstancesAsync(request);
            var instance = response.Reservations[0].Instances[0];
            hasState = instance.State.Name == stateName;
            Console.Write(". ");
        } while (!hasState);

        return hasState;
    }

###############################################################################
# function ec2_start_instances
#
# This function starts one or more Amazon Elastic Compute Cloud (Amazon EC2) instances.
#
# Parameters:
#       -i instance_id - The ID(s) of the instance(s) to start (comma-separated).
#       -h - Display help.
#
# Returns:
#       0 - If successful.
#       1 - If it fails.
###############################################################################
function ec2_start_instances() {
  local instance_ids
  local option OPTARG # Required to use getopts command in a function.

  # bashsupport disable=BP5008
  function usage() {
    echo "function ec2_start_instances"
    echo "Starts one or more Amazon Elastic Compute Cloud (Amazon EC2) instances."
    echo "  -i instance_id - The ID(s) of the instance(s) to start (comma-separated)."
    echo "  -h - Display help."
    echo ""
  }

  # Retrieve the calling parameters.
  while getopts "i:h" option; do
    case "${option}" in
      i) instance_ids="${OPTARG}" ;;
      h)
        usage
        return 0
        ;;
      \?)
        echo "Invalid parameter"
        usage
        return 1
        ;;
    esac
  done
  export OPTIND=1

  if [[ -z "$instance_ids" ]]; then
    errecho "ERROR: You must provide one or more instance IDs with the -i parameter."
    usage
    return 1
  fi

  response=$(aws ec2 start-instances \
    --instance-ids "${instance_ids}") || {
    aws_cli_error_log ${?}
    errecho "ERROR: AWS reports start-instances operation failed with $response."
    return 1
  }

  return 0
}

The utility functions used in this example.

###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
  printf "%s\n" "$*" 1>&2
}

##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# The function expects the following argument:
#         $1 - The error code returned by the AWS CLI.
#
#  Returns:
#          0: - Success.
#
##############################################################################
function aws_cli_error_log() {
  local err_code=$1
  errecho "Error code : $err_code"
  if [ "$err_code" == 1 ]; then
    errecho "  One or more S3 transfers failed."
  elif [ "$err_code" == 2 ]; then
    errecho "  Command line failed to parse."
  elif [ "$err_code" == 130 ]; then
    errecho "  Process received SIGINT."
  elif [ "$err_code" == 252 ]; then
    errecho "  Command syntax invalid."
  elif [ "$err_code" == 253 ]; then
    errecho "  The system environment or configuration was invalid."
  elif [ "$err_code" == 254 ]; then
    errecho "  The service returned an error."
  elif [ "$err_code" == 255 ]; then
    errecho "  255 is a catch-all error."
  fi

  return 0
}

//! Start an Amazon Elastic Compute Cloud (Amazon EC2) instance.
/*!
  \param instanceID: An EC2 instance ID.
  \param clientConfiguration: AWS client configuration.
  \return bool: Function succeeded.
 */
bool AwsDoc::EC2::startInstance(const Aws::String &instanceId,
                                const Aws::Client::ClientConfiguration &clientConfiguration) {
    Aws::EC2::EC2Client ec2Client(clientConfiguration);

    Aws::EC2::Model::StartInstancesRequest startRequest;
    startRequest.AddInstanceIds(instanceId);
    startRequest.SetDryRun(true);

    Aws::EC2::Model::StartInstancesOutcome dryRunOutcome = ec2Client.StartInstances(startRequest);
    if (dryRunOutcome.IsSuccess()) {
        std::cerr
                << "Failed dry run to start instance. A dry run should trigger an error."
                << std::endl;
        return false;
    } else if (dryRunOutcome.GetError().GetErrorType() !=
               Aws::EC2::EC2Errors::DRY_RUN_OPERATION) {
        std::cout << "Failed dry run to start instance " << instanceId << ": "
                  << dryRunOutcome.GetError().GetMessage() << std::endl;
        return false;
    }

    startRequest.SetDryRun(false);
    Aws::EC2::Model::StartInstancesOutcome startInstancesOutcome = ec2Client.StartInstances(startRequest);

    if (!startInstancesOutcome.IsSuccess()) {
        std::cout << "Failed to start instance " << instanceId << ": " <<
                  startInstancesOutcome.GetError().GetMessage() << std::endl;
    } else {
        std::cout << "Successfully started instance " << instanceId <<
                  std::endl;
    }

    return startInstancesOutcome.IsSuccess();
}

To start an Amazon EC2 instance

This example starts the specified Amazon EBS-backed instance.

Command:

aws ec2 start-instances --instance-ids i-1234567890abcdef0

Output:

{
    "StartingInstances": [
        {
            "InstanceId": "i-1234567890abcdef0",
            "CurrentState": {
                "Code": 0,
                "Name": "pending"
            },
            "PreviousState": {
                "Code": 80,
                "Name": "stopped"
            }
        }
    ]
}

For more information, see Stop and Start Your Instance in the Amazon Elastic Compute Cloud User Guide.

    /**
     * Starts an Amazon EC2 instance asynchronously and waits until it is in the "running" state.
     *
     * @param instanceId the ID of the instance to start
     * @return a {@link CompletableFuture} that completes when the instance has been started and is in the "running" state, or exceptionally if an error occurs
     */
    public CompletableFuture<Void> startInstanceAsync(String instanceId) {
        StartInstancesRequest startRequest = StartInstancesRequest.builder()
            .instanceIds(instanceId)
            .build();

        Ec2AsyncWaiter ec2Waiter = Ec2AsyncWaiter.builder()
            .client(getAsyncClient())
            .build();

        DescribeInstancesRequest describeRequest = DescribeInstancesRequest.builder()
            .instanceIds(instanceId)
            .build();

        logger.info("Starting instance " + instanceId + " and waiting for it to run.");
        CompletableFuture<Void> resultFuture = new CompletableFuture<>();
        return getAsyncClient().startInstances(startRequest)
            .thenCompose(response ->
                ec2Waiter.waitUntilInstanceRunning(describeRequest)
            )
            .thenAccept(waiterResponse -> {
                logger.info("Successfully started instance " + instanceId);
                resultFuture.complete(null);
            })
            .exceptionally(throwable -> {
                resultFuture.completeExceptionally(new RuntimeException("Failed to start instance: " + throwable.getMessage(), throwable));
                return null;
            });
    }

import { EC2Client, StartInstancesCommand } from "@aws-sdk/client-ec2";
import { fileURLToPath } from "node:url";
import { parseArgs } from "node:util";

/**
 * Starts an Amazon EBS-backed instance that you've previously stopped.
 * @param {{ instanceIds }} options
 */
export const main = async ({ instanceIds }) => {
  const client = new EC2Client({});
  const command = new StartInstancesCommand({
    InstanceIds: instanceIds,
  });

  try {
    const { StartingInstances } = await client.send(command);
    const instanceIdList = StartingInstances.map(
      (instance) => ` • ${instance.InstanceId}`,
    );
    console.log("Starting instances:");
    console.log(instanceIdList.join("\n"));
  } catch (caught) {
    if (
      caught instanceof Error &&
      caught.name === "InvalidInstanceID.NotFound"
    ) {
      console.warn(`${caught.message}`);
    } else {
      throw caught;
    }
  }
};

suspend fun startInstanceSc(instanceId: String) {
    val request =
        StartInstancesRequest {
            instanceIds = listOf(instanceId)
        }

    Ec2Client { region = "us-west-2" }.use { ec2 ->
        ec2.startInstances(request)
        println("Waiting until instance $instanceId starts. This will take a few minutes.")
        ec2.waitUntilInstanceRunning {
            // suspend call
            instanceIds = listOf(instanceId)
        }
        println("Successfully started instance $instanceId")
    }
}

Example 1: This example starts the specified instance.

Start-EC2Instance -InstanceId i-12345678

Output:

CurrentState                      InstanceId    PreviousState
------------                      ----------    -------------
Amazon.EC2.Model.InstanceState    i-12345678    Amazon.EC2.Model.InstanceState

Example 2: This example starts the specified instances.

@("i-12345678", "i-76543210") | Start-EC2Instance

Example 3: This example starts the set of instances that are currently stopped. The Instance objects returned by Get-EC2Instance are piped to Start-EC2Instance. The syntax used by this example requires PowerShell version 3 or higher.

(Get-EC2Instance -Filter @{ Name="instance-state-name"; Values="stopped"}).Instances | Start-EC2Instance

Example 4: With PowerShell version 2, you must use New-Object to create the filter for the Filter parameter.

$filter = New-Object Amazon.EC2.Model.Filter
$filter.Name = "instance-state-name"
$filter.Values = "stopped"

(Get-EC2Instance -Filter $filter).Instances | Start-EC2Instance

class EC2InstanceWrapper:
    """Encapsulates Amazon Elastic Compute Cloud (Amazon EC2) instance actions using the client interface."""

    def __init__(
        self, ec2_client: Any, instances: Optional[List[Dict[str, Any]]] = None
    ) -> None:
        """
        Initializes the EC2InstanceWrapper with an EC2 client and optional instances.

        :param ec2_client: A Boto3 Amazon EC2 client. This client provides low-level
                           access to AWS EC2 services.
        :param instances: A list of dictionaries representing Boto3 Instance objects. These are high-level objects that
                          wrap instance actions.
        """
        self.ec2_client = ec2_client
        self.instances = instances or []

    @classmethod
    def from_client(cls) -> "EC2InstanceWrapper":
        """
        Creates an EC2InstanceWrapper instance with a default EC2 client.

        :return: An instance of EC2InstanceWrapper initialized with the default EC2 client.
        """
        ec2_client = boto3.client("ec2")
        return cls(ec2_client)


    def start(self) -> Optional[Dict[str, Any]]:
        """
        Starts instances and waits for them to be in a running state.

        :return: The response to the start request.
        """
        if not self.instances:
            logger.info("No instances to start.")
            return None

        instance_ids = [instance["InstanceId"] for instance in self.instances]
        try:
            start_response = self.ec2_client.start_instances(InstanceIds=instance_ids)
            waiter = self.ec2_client.get_waiter("instance_running")
            waiter.wait(InstanceIds=instance_ids)
            return start_response
        except ClientError as err:
            logger.error(
                f"Failed to start instance(s): {','.join(map(str, instance_ids))}"
            )
            error_code = err.response["Error"]["Code"]
            if error_code == "IncorrectInstanceState":
                logger.error(
                    "Couldn't start instance(s) because they are in an incorrect state. "
                    "Ensure the instances are in a stopped state before starting them."
                )
            raise

require 'aws-sdk-ec2'

# Attempts to start an Amazon Elastic Compute Cloud (Amazon EC2) instance.
#
# Prerequisites:
#
# - The Amazon EC2 instance.
#
# @param ec2_client [Aws::EC2::Client] An initialized EC2 client.
# @param instance_id [String] The ID of the instance.
# @return [Boolean] true if the instance was started; otherwise, false.
# @example
#   exit 1 unless instance_started?(
#     Aws::EC2::Client.new(region: 'us-west-2'),
#     'i-123abc'
#   )
def instance_started?(ec2_client, instance_id)
  response = ec2_client.describe_instance_status(instance_ids: [instance_id])

  if response.instance_statuses.count.positive?
    state = response.instance_statuses[0].instance_state.name
    case state
    when 'pending'
      puts 'Error starting instance: the instance is pending. Try again later.'
      return false
    when 'running'
      puts 'The instance is already running.'
      return true
    when 'terminated'
      puts 'Error starting instance: ' \
        'the instance is terminated, so you cannot start it.'
      return false
    end
  end

  ec2_client.start_instances(instance_ids: [instance_id])
  ec2_client.wait_until(:instance_running, instance_ids: [instance_id])
  puts 'Instance started.'
  true
rescue StandardError => e
  puts "Error starting instance: #{e.message}"
  false
end

# Example usage:
def run_me
  instance_id = ''
  region = ''
  # Print usage information and then stop.
  if ARGV[0] == '--help' || ARGV[0] == '-h'
    puts 'Usage:   ruby ec2-ruby-example-start-instance-i-123abc.rb ' \
      'INSTANCE_ID REGION '
    # Replace us-west-2 with the AWS Region you're using for Amazon EC2.
    puts 'Example: ruby ec2-ruby-example-start-instance-i-123abc.rb ' \
      'i-123abc us-west-2'
    exit 1
  # If no values are specified at the command prompt, use these default values.
  # Replace us-west-2 with the AWS Region you're using for Amazon EC2.
  elsif ARGV.count.zero?
    instance_id = 'i-123abc'
    region = 'us-west-2'
  # Otherwise, use the values as specified at the command prompt.
  else
    instance_id = ARGV[0]
    region = ARGV[1]
  end

  ec2_client = Aws::EC2::Client.new(region: region)

  puts "Attempting to start instance '#{instance_id}' " \
    '(this might take a few minutes)...'
  return if instance_started?(ec2_client, instance_id)

  puts 'Could not start instance.'
end

run_me if $PROGRAM_NAME == __FILE__

Start an EC2 Instance by instance ID.

    pub async fn start_instance(&self, instance_id: &str) -> Result<(), EC2Error> {
        tracing::info!("Starting instance {instance_id}");

        self.client
            .start_instances()
            .instance_ids(instance_id)
            .send()
            .await?;

        tracing::info!("Started instance.");

        Ok(())
    }

Wait for an instance to be in the ready and status ok states, using the Waiters API. Using the Waiters API requires `use aws_sdk_ec2::client::Waiters` in the rust file.

    /// Wait for an instance to be ready and status ok (default wait 60 seconds)
    pub async fn wait_for_instance_ready(
        &self,
        instance_id: &str,
        duration: Option<Duration>,
    ) -> Result<(), EC2Error> {
        self.client
            .wait_until_instance_status_ok()
            .instance_ids(instance_id)
            .wait(duration.unwrap_or(Duration::from_secs(60)))
            .await
            .map_err(|err| match err {
                WaiterError::ExceededMaxWait(exceeded) => EC2Error(format!(
                    "Exceeded max time ({}s) waiting for instance to start.",
                    exceeded.max_wait().as_secs()
                )),
                _ => EC2Error::from(err),
            })?;
        Ok(())
    }

    DATA lt_instance_ids TYPE /aws1/cl_ec2instidstringlist_w=>tt_instanceidstringlist.
    APPEND NEW /aws1/cl_ec2instidstringlist_w( iv_value = iv_instance_id ) TO lt_instance_ids.

    "Perform dry run"
    TRY.
        " DryRun is set to true. This checks for the required permissions to start the instance without actually making the request. "
        lo_ec2->startinstances(
          it_instanceids = lt_instance_ids
          iv_dryrun = abap_true
        ).
      CATCH /aws1/cx_rt_service_generic INTO DATA(lo_exception).
        " If the error code returned is `DryRunOperation`, then you have the required permissions to start this instance. "
        IF lo_exception->av_err_code = 'DryRunOperation'.
          MESSAGE 'Dry run to start instance completed.' TYPE 'I'.
          " DryRun is set to false to start instance. "
          oo_result = lo_ec2->startinstances(           " oo_result is returned for testing purposes. "
            it_instanceids = lt_instance_ids
            iv_dryrun = abap_false
          ).
          MESSAGE 'Successfully started the EC2 instance.' TYPE 'I'.
          " If the error code returned is `UnauthorizedOperation`, then you don't have the required permissions to start this instance. "
        ELSEIF lo_exception->av_err_code = 'UnauthorizedOperation'.
          MESSAGE 'Dry run to start instance failed. User does not have permissions to start the instance.' TYPE 'E'.
        ELSE.
          DATA(lv_error) = |"{ lo_exception->av_err_code }" - { lo_exception->av_err_msg }|.
          MESSAGE lv_error TYPE 'E'.
        ENDIF.
    ENDTRY.