Fix assigning public ip to instances. Closes #729.

moto/ec2/models.py

@@ -549,6 +549,10 @@ class Instance(BotoInstance, TaggedEC2Resource):
 
             self.attach_eni(use_nic, device_index)
 
+    def set_ip(self, ip_address):
+        # Should we be creating a new ENI?
+        self.nics[0].public_ip = ip_address
+
     def attach_eni(self, eni, device_index):
         device_index = int(device_index)
         self.nics[device_index] = eni
@@ -2663,6 +2667,7 @@ class ElasticAddressBackend(object):
                 eip.eni.public_ip = eip.public_ip
             if eip.domain == "vpc":
                 eip.association_id = random_eip_association_id()
+            instance.set_ip(eip.public_ip)
 
             return eip
 

moto/ec2/responses/instances.py

@@ -207,6 +207,7 @@ EC2_RUN_INSTANCES = """<RunInstancesResponse xmlns="http://ec2.amazonaws.com/doc
           </instanceState>
           <privateDnsName>{{ instance.private_dns }}</privateDnsName>
           <publicDnsName>{{ instance.public_dns }}</publicDnsName>
+          <dnsName>{{ instance.public_dns }}</dnsName>
           <reason/>
           <keyName>{{ instance.key_name }}</keyName>
           <amiLaunchIndex>0</amiLaunchIndex>
@@ -335,6 +336,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns="http://ec2.amazona
                     </instanceState>
                     <privateDnsName>{{ instance.private_dns }}</privateDnsName>
                     <publicDnsName>{{ instance.public_dns }}</publicDnsName>
+                    <dnsName>{{ instance.public_dns }}</dnsName>
                     <reason>{{ instance._reason }}</reason>
                     <keyName>{{ instance.key_name }}</keyName>
                     <amiLaunchIndex>0</amiLaunchIndex>

tests/test_ec2/test_elastic_ip_addresses.py

@@ -4,6 +4,7 @@ import tests.backport_assert_raises
 from nose.tools import assert_raises
 
 import boto
+import boto3
 from boto.exception import EC2ResponseError
 import six
 
@@ -110,6 +111,32 @@ def test_eip_associate_vpc():
 
     instance.terminate()
 
+@mock_ec2
+def test_eip_boto3_vpc_association():
+    """Associate EIP to VPC instance in a new subnet with boto3"""
+    session = boto3.session.Session(region_name='us-west-1')
+    service = session.resource('ec2')
+    client = session.client('ec2')
+    vpc_res = client.create_vpc(CidrBlock='10.0.0.0/24')
+    subnet_res = client.create_subnet(
+            VpcId=vpc_res['Vpc']['VpcId'], CidrBlock='10.0.0.0/24')
+    instance = service.create_instances(**{
+        'InstanceType': 't2.micro',
+        'ImageId': 'ami-test',
+        'MinCount': 1,
+        'MaxCount': 1,
+        'SubnetId': subnet_res['Subnet']['SubnetId']
+    })[0]
+    allocation_id = client.allocate_address(Domain='vpc')['AllocationId']
+    association_id = client.associate_address(
+        InstanceId=instance.id,
+        AllocationId=allocation_id,
+        AllowReassociation=False)
+    instance.load()
+    instance.public_ip_address.should_not.be.none
+    instance.public_dns_name.should_not.be.none
+
+
 @mock_ec2
 def test_eip_associate_network_interface():
     """Associate/Disassociate EIP to NIC"""