Use RebootInstances with an AWS SDK or CLI

Reboot an instance by its Id.

    /// <summary>
    /// Reboot a specific EC2 instance.
    /// </summary>
    /// <param name="ec2InstanceId">The instance Id of the instance that will be rebooted.</param>
    /// <returns>Async Task.</returns>
    public async Task<bool> RebootInstances(string ec2InstanceId)
    {
        try
        {
            var request = new RebootInstancesRequest
            {
                InstanceIds = new List<string> { ec2InstanceId },
            };

            await _amazonEC2.RebootInstancesAsync(request);

            // Wait for the instance to be running.
            Console.Write("Waiting for the instance to start.");
            await WaitForInstanceState(ec2InstanceId, InstanceStateName.Running);

            return true;
        }
        catch (AmazonEC2Exception ec2Exception)
        {
            if (ec2Exception.ErrorCode == "InvalidInstanceId")
            {
                _logger.LogError(
                    $"InstanceId {ec2InstanceId} is invalid, unable to reboot. {ec2Exception.Message}");
            }
            return false;
        }
        catch (Exception ex)
        {
            _logger.LogError(
                $"An error occurred while rebooting the instance {ec2InstanceId}.: {ex.Message}");
            return false;
        }
    }

    /// <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;
    }

Replace the profile for an instance, reboot, and restart a web server.

    /// <summary>
    /// Replace the profile associated with a running instance. After the profile is replaced, the instance
    /// is rebooted to ensure that it uses the new profile. When the instance is ready, Systems Manager is
    /// used to restart the Python web server.
    /// </summary>
    /// <param name="instanceId">The Id of the instance to update.</param>
    /// <param name="credsProfileName">The name of the new profile to associate with the specified instance.</param>
    /// <param name="associationId">The Id of the existing profile association for the instance.</param>
    /// <returns>Async task.</returns>
    public async Task ReplaceInstanceProfile(string instanceId, string credsProfileName, string associationId)
    {
        try
        {
            await _amazonEc2.ReplaceIamInstanceProfileAssociationAsync(
                new ReplaceIamInstanceProfileAssociationRequest()
                {
                    AssociationId = associationId,
                    IamInstanceProfile = new IamInstanceProfileSpecification()
                    {
                        Name = credsProfileName
                    }
                });
            // Allow time before resetting.
            Thread.Sleep(25000);

            await _amazonEc2.RebootInstancesAsync(
                new RebootInstancesRequest(new List<string>() { instanceId }));
            Thread.Sleep(25000);
            var instanceReady = false;
            var retries = 5;
            while (retries-- > 0 && !instanceReady)
            {
                var instancesPaginator =
                    _amazonSsm.Paginators.DescribeInstanceInformation(
                        new DescribeInstanceInformationRequest());
                // Get the entire list using the paginator.
                await foreach (var instance in instancesPaginator.InstanceInformationList)
                {
                    instanceReady = instance.InstanceId == instanceId;
                    if (instanceReady)
                    {
                        break;
                    }
                }
            }
            Console.WriteLine("Waiting for instance to be running.");
            await WaitForInstanceState(instanceId, InstanceStateName.Running);
            Console.WriteLine("Instance ready.");
            Console.WriteLine($"Sending restart command to instance {instanceId}");
            await _amazonSsm.SendCommandAsync(
                new SendCommandRequest()
                {
                    InstanceIds = new List<string>() { instanceId },
                    DocumentName = "AWS-RunShellScript",
                    Parameters = new Dictionary<string, List<string>>()
                    {
                        {
                            "commands",
                            new List<string>() { "cd / && sudo python3 server.py 80" }
                        }
                    }
                });
            Console.WriteLine($"Restarted the web server on instance {instanceId}");
        }
        catch (AmazonEC2Exception ec2Exception)
        {
            if (ec2Exception.ErrorCode == "InvalidInstanceID.NotFound")
            {
                _logger.LogError(ec2Exception, $"Instance {instanceId} not found");
            }

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

//! Reboot 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::rebootInstance(const Aws::String &instanceId,
                                 const Aws::Client::ClientConfiguration &clientConfiguration) {
    Aws::EC2::EC2Client ec2Client(clientConfiguration);

    Aws::EC2::Model::RebootInstancesRequest request;
    request.AddInstanceIds(instanceId);
    request.SetDryRun(true);

    Aws::EC2::Model::RebootInstancesOutcome dry_run_outcome = ec2Client.RebootInstances(request);
    if (dry_run_outcome.IsSuccess()) {
        std::cerr
                << "Failed dry run to reboot on instance. A dry run should trigger an error."
                <<
                std::endl;
        return false;
    } else if (dry_run_outcome.GetError().GetErrorType()
               != Aws::EC2::EC2Errors::DRY_RUN_OPERATION) {
        std::cout << "Failed dry run to reboot instance " << instanceId << ": "
                  << dry_run_outcome.GetError().GetMessage() << std::endl;
        return false;
    }

    request.SetDryRun(false);
    Aws::EC2::Model::RebootInstancesOutcome outcome = ec2Client.RebootInstances(request);
    if (!outcome.IsSuccess()) {
        std::cout << "Failed to reboot instance " << instanceId << ": " <<
                  outcome.GetError().GetMessage() << std::endl;
    } else {
        std::cout << "Successfully rebooted instance " << instanceId <<
                  std::endl;
    }

    return outcome.IsSuccess();
}

To reboot an Amazon EC2 instance

This example reboots the specified instance. If the command succeeds, no output is returned.

Command:

aws ec2 reboot-instances --instance-ids i-1234567890abcdef5

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

import { EC2Client, RebootInstancesCommand } from "@aws-sdk/client-ec2";

/**
 * Requests a reboot of the specified instances. This operation is asynchronous;
 * it only queues a request to reboot the specified instances.
 * @param {{ instanceIds: string[] }} options
 */
export const main = async ({ instanceIds }) => {
  const client = new EC2Client({});
  const command = new RebootInstancesCommand({
    InstanceIds: instanceIds,
  });

  try {
    await client.send(command);
    console.log("Instance rebooted successfully.");
  } catch (caught) {
    if (
      caught instanceof Error &&
      caught.name === "InvalidInstanceID.NotFound"
    ) {
      console.warn(
        `${caught.message}. Please provide the InstanceId of a valid instance to reboot.`,
      );
    } else {
      throw caught;
    }
  }
};

Example 1: This example reboots the specified instance.

Restart-EC2Instance -InstanceId i-12345678

class AutoScalingWrapper:
    """
    Encapsulates Amazon EC2 Auto Scaling and EC2 management actions.
    """

    def __init__(
        self,
        resource_prefix: str,
        inst_type: str,
        ami_param: str,
        autoscaling_client: boto3.client,
        ec2_client: boto3.client,
        ssm_client: boto3.client,
        iam_client: boto3.client,
    ):
        """
        Initializes the AutoScaler class with the necessary parameters.

        :param resource_prefix: The prefix for naming AWS resources that are created by this class.
        :param inst_type: The type of EC2 instance to create, such as t3.micro.
        :param ami_param: The Systems Manager parameter used to look up the AMI that is created.
        :param autoscaling_client: A Boto3 EC2 Auto Scaling client.
        :param ec2_client: A Boto3 EC2 client.
        :param ssm_client: A Boto3 Systems Manager client.
        :param iam_client: A Boto3 IAM client.
        """
        self.inst_type = inst_type
        self.ami_param = ami_param
        self.autoscaling_client = autoscaling_client
        self.ec2_client = ec2_client
        self.ssm_client = ssm_client
        self.iam_client = iam_client
        sts_client = boto3.client("sts")
        self.account_id = sts_client.get_caller_identity()["Account"]

        self.key_pair_name = f"{resource_prefix}-key-pair"
        self.launch_template_name = f"{resource_prefix}-template-"
        self.group_name = f"{resource_prefix}-group"

        # Happy path
        self.instance_policy_name = f"{resource_prefix}-pol"
        self.instance_role_name = f"{resource_prefix}-role"
        self.instance_profile_name = f"{resource_prefix}-prof"

        # Failure mode
        self.bad_creds_policy_name = f"{resource_prefix}-bc-pol"
        self.bad_creds_role_name = f"{resource_prefix}-bc-role"
        self.bad_creds_profile_name = f"{resource_prefix}-bc-prof"


    def replace_instance_profile(
        self,
        instance_id: str,
        new_instance_profile_name: str,
        profile_association_id: str,
    ) -> None:
        """
        Replaces the profile associated with a running instance. After the profile is
        replaced, the instance is rebooted to ensure that it uses the new profile. When
        the instance is ready, Systems Manager is used to restart the Python web server.

        :param instance_id: The ID of the instance to restart.
        :param new_instance_profile_name: The name of the new profile to associate with
                                          the specified instance.
        :param profile_association_id: The ID of the existing profile association for the
                                       instance.
        """
        try:
            self.ec2_client.replace_iam_instance_profile_association(
                IamInstanceProfile={"Name": new_instance_profile_name},
                AssociationId=profile_association_id,
            )
            log.info(
                "Replaced instance profile for association %s with profile %s.",
                profile_association_id,
                new_instance_profile_name,
            )
            time.sleep(5)

            self.ec2_client.reboot_instances(InstanceIds=[instance_id])
            log.info("Rebooting instance %s.", instance_id)
            waiter = self.ec2_client.get_waiter("instance_running")
            log.info("Waiting for instance %s to be running.", instance_id)
            waiter.wait(InstanceIds=[instance_id])
            log.info("Instance %s is now running.", instance_id)

            self.ssm_client.send_command(
                InstanceIds=[instance_id],
                DocumentName="AWS-RunShellScript",
                Parameters={"commands": ["cd / && sudo python3 server.py 80"]},
            )
            log.info(f"Restarted the Python web server on instance '{instance_id}'.")
        except ClientError as err:
            log.error("Failed to replace instance profile.")
            error_code = err.response["Error"]["Code"]
            if error_code == "InvalidAssociationID.NotFound":
                log.error(
                    f"Association ID '{profile_association_id}' does not exist."
                    "Please check the association ID and try again."
                )
            if error_code == "InvalidInstanceId":
                log.error(
                    f"The specified instance ID '{instance_id}' does not exist or is not available for SSM. "
                    f"Please verify the instance ID and try again."
                )
            log.error(f"Full error:\n\t{err}")

    pub async fn reboot(&self, ec2: &EC2) -> Result<(), EC2Error> {
        if self.instance.is_some() {
            ec2.reboot_instance(self.instance_id()).await?;
            ec2.wait_for_instance_stopped(self.instance_id(), None)
                .await?;
            ec2.wait_for_instance_ready(self.instance_id(), None)
                .await?;
        }
        Ok(())
    }

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

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

        Ok(())
    }

Waiters for instance to be in the stopped and ready 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(())
    }

    pub async fn wait_for_instance_stopped(
        &self,
        instance_id: &str,
        duration: Option<Duration>,
    ) -> Result<(), EC2Error> {
        self.client
            .wait_until_instance_stopped()
            .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 stop.",
                    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 reboot the instance without actually making the request. "
        lo_ec2->rebootinstances(
          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 reboot this instance. "
        IF lo_exception->av_err_code = 'DryRunOperation'.
          MESSAGE 'Dry run to reboot instance completed.' TYPE 'I'.
          " DryRun is set to false to make a reboot request. "
          lo_ec2->rebootinstances(
             it_instanceids = lt_instance_ids
             iv_dryrun = abap_false
           ).
          MESSAGE 'Instance rebooted.' TYPE 'I'.
          " If the error code returned is `UnauthorizedOperation`, then you don't have the required permissions to reboot this instance. "
        ELSEIF lo_exception->av_err_code = 'UnauthorizedOperation'.
          MESSAGE 'Dry run to reboot instance failed. User does not have permissions to reboot 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.