From e8ea958444cb4d41d4155438952401b5c3d31b85 Mon Sep 17 00:00:00 2001
From: szopen321 <32538420+szopen321@users.noreply.github.com>
Date: Wed, 25 May 2022 16:18:03 +0200
Subject: [PATCH] EC2 - Add keypair validation (#5152)

---
 moto/ec2/models/instances.py     |  2 ++
 moto/ec2/models/key_pairs.py     |  2 +-
 moto/settings.py                 |  4 ++++
 tests/test_ec2/test_instances.py | 26 ++++++++++++++++++++++++++
 4 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/moto/ec2/models/instances.py b/moto/ec2/models/instances.py
index ef5b3ba37..d9de06873 100644
--- a/moto/ec2/models/instances.py
+++ b/moto/ec2/models/instances.py
@@ -553,6 +553,8 @@ class InstanceBackend(object):
     def add_instances(self, image_id, count, user_data, security_group_names, **kwargs):
         location_type = "availability-zone" if kwargs.get("placement") else "region"
         default_region = "us-east-1"
+        if settings.ENABLE_KEYPAIR_VALIDATION:
+            self.describe_key_pairs(key_names=[kwargs.get("key_name")])
         valid_instance_types = INSTANCE_TYPE_OFFERINGS[location_type]
         if "region_name" in kwargs and kwargs.get("placement"):
             valid_availability_zones = {
diff --git a/moto/ec2/models/key_pairs.py b/moto/ec2/models/key_pairs.py
index 7075f7e7f..ac9b5f58d 100644
--- a/moto/ec2/models/key_pairs.py
+++ b/moto/ec2/models/key_pairs.py
@@ -46,7 +46,7 @@ class KeyPairBackend(object):
 
     def describe_key_pairs(self, key_names=None, filters=None):
         results = []
-        if key_names:
+        if any(key_names):
             results = [
                 keypair
                 for keypair in self.keypairs.values()
diff --git a/moto/settings.py b/moto/settings.py
index 8a3bffaa8..de91b5c66 100644
--- a/moto/settings.py
+++ b/moto/settings.py
@@ -22,6 +22,10 @@ EC2_ENABLE_INSTANCE_TYPE_VALIDATION = bool(
     os.environ.get("MOTO_EC2_ENABLE_INSTANCE_TYPE_VALIDATION", False)
 )
 
+ENABLE_KEYPAIR_VALIDATION = bool(
+    os.environ.get("MOTO_ENABLE_KEYPAIR_VALIDATION", False)
+)
+
 
 def get_sf_execution_history_type():
     """
diff --git a/tests/test_ec2/test_instances.py b/tests/test_ec2/test_instances.py
index e0c34cb14..6c416af11 100644
--- a/tests/test_ec2/test_instances.py
+++ b/tests/test_ec2/test_instances.py
@@ -1561,6 +1561,7 @@ def test_ec2_classic_has_public_ip_address():
 @mock_ec2
 def test_run_instance_with_keypair():
     ec2 = boto3.resource("ec2", region_name="us-east-1")
+
     instance = ec2.create_instances(
         ImageId=EXAMPLE_AMI_ID, MinCount=1, MaxCount=1, KeyName="keypair_name"
     )[0]
@@ -1568,6 +1569,30 @@ def test_run_instance_with_keypair():
     instance.key_name.should.equal("keypair_name")
 
 
+@mock_ec2
+@mock.patch(
+    "moto.ec2.models.instances.settings.ENABLE_KEYPAIR_VALIDATION",
+    new_callable=mock.PropertyMock(return_value=True),
+)
+def test_run_instance_with_invalid_keypair(m_flag):
+    if settings.TEST_SERVER_MODE:
+        raise SkipTest(
+            "It is not possible to set the environment variable in server mode"
+        )
+    ec2 = boto3.resource("ec2", region_name="us-east-1")
+    keypair_name = "keypair_name"
+    ec2.create_key_pair(KeyName=keypair_name)
+
+    with pytest.raises(ClientError) as ex:
+        ec2.create_instances(
+            ImageId=EXAMPLE_AMI_ID, MinCount=1, MaxCount=1, KeyName="not a key name"
+        )[0]
+
+    ex.value.response["ResponseMetadata"]["HTTPStatusCode"].should.equal(400)
+    ex.value.response["Error"]["Code"].should.equal("InvalidKeyPair.NotFound")
+    assert m_flag is True
+
+
 @mock_ec2
 def test_run_instance_with_block_device_mappings():
     ec2_client = boto3.client("ec2", region_name="us-east-1")
@@ -1684,6 +1709,7 @@ def test_run_instance_with_block_device_mappings_missing_size():
 def test_run_instance_with_block_device_mappings_from_snapshot():
     ec2_client = boto3.client("ec2", region_name="us-east-1")
     ec2_resource = boto3.resource("ec2", region_name="us-east-1")
+
     volume_details = {
         "AvailabilityZone": "1a",
         "Size": 30,