Use ReleaseAddress with an Amazon SDK or CLI

    /// <summary>
    /// Release an Elastic IP address.
    /// </summary>
    /// <param name="allocationId">The allocation Id of the Elastic IP address.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> ReleaseAddress(string allocationId)
    {
        var request = new ReleaseAddressRequest
        {
            AllocationId = allocationId
        };

        var response = await _amazonEC2.ReleaseAddressAsync(request);
        return response.HttpStatusCode == HttpStatusCode.OK;
    }

###############################################################################
# function ec2_release_address
#
# This function releases an Elastic IP address from an Amazon Elastic Compute Cloud (Amazon EC2) instance.
#
# Parameters:
#       -a allocation_id - The allocation ID of the Elastic IP address to release.
#
# Returns:
#       0 - If successful.
#       1 - If it fails.
#
###############################################################################
function ec2_release_address() {
  local allocation_id response

  # Function to display usage information
  function usage() {
    echo "function ec2_release_address"
    echo "Releases an Elastic IP address from an Amazon Elastic Compute Cloud (Amazon EC2) instance."
    echo "  -a allocation_id - The allocation ID of the Elastic IP address to release."
    echo ""
  }

  # Parse the command-line arguments
  while getopts "a:h" option; do
    case "${option}" in
      a) allocation_id="${OPTARG}" ;;
      h)
        usage
        return 0
        ;;
      \?)
        echo "Invalid parameter"
        usage
        return 1
        ;;
    esac
  done
  export OPTIND=1

  # Validate the input parameters
  if [[ -z "$allocation_id" ]]; then
    errecho "ERROR: You must provide an allocation ID with the -a parameter."
    return 1
  fi

  response=$(aws ec2 release-address \
    --allocation-id "$allocation_id") || {
    aws_cli_error_log ${?}
    errecho "ERROR: AWS reports release-address operation failed."
    errecho "$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
}

    Aws::EC2::EC2Client ec2(clientConfiguration);

    Aws::EC2::Model::ReleaseAddressRequest request;
    request.SetAllocationId(allocationID);

    auto outcome = ec2.ReleaseAddress(request);
    if (!outcome.IsSuccess()) {
        std::cerr << "Failed to release Elastic IP address " <<
                  allocationID << ":" << outcome.GetError().GetMessage() <<
                  std::endl;
    }
    else {
        std::cout << "Successfully released Elastic IP address " <<
                  allocationID << std::endl;
    }

To release an Elastic IP addresses for EC2-Classic

This example releases an Elastic IP address for use with instances in EC2-Classic. If the command succeeds, no output is returned.

Command:

aws ec2 release-address --public-ip 198.51.100.0

To release an Elastic IP address for EC2-VPC

This example releases an Elastic IP address for use with instances in a VPC. If the command succeeds, no output is returned.

Command:

aws ec2 release-address --allocation-id eipalloc-64d5890a

    public static void releaseEC2Address(Ec2Client ec2, String allocId) {
        try {
            ReleaseAddressRequest request = ReleaseAddressRequest.builder()
                    .allocationId(allocId)
                    .build();

            ec2.releaseAddress(request);
            System.out.println("Successfully released Elastic IP address " + allocId);
        } catch (Ec2Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

import { ReleaseAddressCommand } from "@aws-sdk/client-ec2";

import { client } from "../libs/client.js";

export const main = async () => {
  const command = new ReleaseAddressCommand({
    // You can also use PublicIp, but that is for EC2 classic which is being retired.
    AllocationId: "ALLOCATION_ID",
  });

  try {
    await client.send(command);
    console.log("Successfully released address.");
  } catch (err) {
    console.error(err);
  }
};

suspend fun releaseEC2AddressSc(allocId: String?) {
    val request =
        ReleaseAddressRequest {
            allocationId = allocId
        }

    Ec2Client { region = "us-west-2" }.use { ec2 ->
        ec2.releaseAddress(request)
        println("Successfully released Elastic IP address $allocId")
    }
}

Example 1: This example releases the specified Elastic IP address for instances in a VPC.

Remove-EC2Address -AllocationId eipalloc-12345678 -Force

Example 2: This example releases the specified Elastic IP address for instances in EC2-Classic.

Remove-EC2Address -PublicIp 198.51.100.2 -Force

class ElasticIpWrapper:
    """Encapsulates Amazon Elastic Compute Cloud (Amazon EC2) Elastic IP address actions."""

    def __init__(self, ec2_resource, elastic_ip=None):
        """
        :param ec2_resource: A Boto3 Amazon EC2 resource. This high-level resource
                             is used to create additional high-level objects
                             that wrap low-level Amazon EC2 service actions.
        :param elastic_ip: A Boto3 VpcAddress object. This is a high-level object that
                           wraps Elastic IP actions.
        """
        self.ec2_resource = ec2_resource
        self.elastic_ip = elastic_ip

    @classmethod
    def from_resource(cls):
        ec2_resource = boto3.resource("ec2")
        return cls(ec2_resource)


    def release(self):
        """
        Releases an Elastic IP address. After the Elastic IP address is released,
        it can no longer be used.
        """
        if self.elastic_ip is None:
            logger.info("No Elastic IP to release.")
            return

        try:
            self.elastic_ip.release()
        except ClientError as err:
            logger.error(
                "Couldn't release Elastic IP address %s. Here's why: %s: %s",
                self.elastic_ip.allocation_id,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

# Releases an Elastic IP address from an
# Amazon Elastic Compute Cloud (Amazon EC2) instance.
#
# Prerequisites:
#
# - An Amazon EC2 instance with an associated Elastic IP address.
#
# @param ec2_client [Aws::EC2::Client] An initialized EC2 client.
# @param allocation_id [String] The ID of the allocation corresponding to
#   the Elastic IP address.
# @return [Boolean] true if the Elastic IP address was released;
#   otherwise, false.
# @example
#   exit 1 unless elastic_ip_address_released?(
#     Aws::EC2::Client.new(region: 'us-west-2'),
#     'eipalloc-04452e528a66279EX'
#   )
def elastic_ip_address_released?(ec2_client, allocation_id)
  ec2_client.release_address(allocation_id: allocation_id)
  return true
rescue StandardError => e
  puts("Error releasing Elastic IP address: #{e.message}")
  return false
end

    TRY.
        lo_ec2->releaseaddress( iv_allocationid = iv_allocation_id ).
        MESSAGE 'Elastic IP address released.' TYPE 'I'.
      CATCH /aws1/cx_rt_service_generic INTO DATA(lo_exception).
        DATA(lv_error) = |"{ lo_exception->av_err_code }" - { lo_exception->av_err_msg }|.
        MESSAGE lv_error TYPE 'E'.
    ENDTRY.