diff --git a/moto/awslambda/models.py b/moto/awslambda/models.py
index c522885ee..a58582599 100644
--- a/moto/awslambda/models.py
+++ b/moto/awslambda/models.py
@@ -304,6 +304,8 @@ class LambdaFunction(BaseModel):
                 self.timeout = value
             elif key == "VpcConfig":
                 self.vpc_config = value
+            elif key == "Environment":
+                self.environment_vars = value["Variables"]
 
         return self.get_configuration()
 
@@ -634,7 +636,7 @@ class LambdaStorage(object):
     def _get_alias(self, name, alias):
         return self._functions[name]["alias"].get(alias, None)
 
-    def get_function(self, name, qualifier=None):
+    def get_function_by_name(self, name, qualifier=None):
         if name not in self._functions:
             return None
 
@@ -657,8 +659,8 @@ class LambdaStorage(object):
     def get_arn(self, arn):
         return self._arns.get(arn, None)
 
-    def get_function_by_name_or_arn(self, input):
-        return self.get_function(input) or self.get_arn(input)
+    def get_function_by_name_or_arn(self, input, qualifier=None):
+        return self.get_function_by_name(input, qualifier) or self.get_arn(input)
 
     def put_function(self, fn):
         """
@@ -719,7 +721,7 @@ class LambdaStorage(object):
                 return True
 
             else:
-                fn = self.get_function(name, qualifier)
+                fn = self.get_function_by_name(name, qualifier)
                 if fn:
                     self._functions[name]["versions"].remove(fn)
 
@@ -822,8 +824,10 @@ class LambdaBackend(BaseBackend):
     def publish_function(self, function_name):
         return self._lambdas.publish_function(function_name)
 
-    def get_function(self, function_name, qualifier=None):
-        return self._lambdas.get_function(function_name, qualifier)
+    def get_function(self, function_name_or_arn, qualifier=None):
+        return self._lambdas.get_function_by_name_or_arn(
+            function_name_or_arn, qualifier
+        )
 
     def list_versions_by_function(self, function_name):
         return self._lambdas.list_versions_by_function(function_name)
@@ -928,7 +932,7 @@ class LambdaBackend(BaseBackend):
                 }
             ]
         }
-        func = self._lambdas.get_function(function_name, qualifier)
+        func = self._lambdas.get_function_by_name_or_arn(function_name, qualifier)
         func.invoke(json.dumps(event), {}, {})
 
     def send_dynamodb_items(self, function_arn, items, source):
diff --git a/moto/awslambda/responses.py b/moto/awslambda/responses.py
index 888844502..62265b310 100644
--- a/moto/awslambda/responses.py
+++ b/moto/awslambda/responses.py
@@ -286,7 +286,7 @@ class LambdaResponse(BaseResponse):
             return 404, {}, "{}"
 
     def _get_function(self, request, full_url, headers):
-        function_name = self.path.rsplit("/", 1)[-1]
+        function_name = unquote(self.path.rsplit("/", 1)[-1])
         qualifier = self._get_param("Qualifier", None)
 
         fn = self.lambda_backend.get_function(function_name, qualifier)
diff --git a/tests/test_awslambda/test_lambda.py b/tests/test_awslambda/test_lambda.py
index e891ddec8..306deeea4 100644
--- a/tests/test_awslambda/test_lambda.py
+++ b/tests/test_awslambda/test_lambda.py
@@ -388,6 +388,7 @@ def test_get_function():
         Timeout=3,
         MemorySize=128,
         Publish=True,
+        Environment={"Variables": {"test_variable": "test_value"}},
     )
 
     result = conn.get_function(FunctionName="testFunction")
@@ -416,6 +417,11 @@ def test_get_function():
     result["Configuration"]["Timeout"].should.equal(3)
     result["Configuration"]["Version"].should.equal("$LATEST")
     result["Configuration"].should.contain("VpcConfig")
+    result["Configuration"].should.contain("Environment")
+    result["Configuration"]["Environment"].should.contain("Variables")
+    result["Configuration"]["Environment"]["Variables"].should.equal(
+        {"test_variable": "test_value"}
+    )
 
     # Test get function with
     result = conn.get_function(FunctionName="testFunction", Qualifier="$LATEST")
@@ -429,6 +435,33 @@ def test_get_function():
         conn.get_function(FunctionName="junk", Qualifier="$LATEST")
 
 
+@mock_lambda
+@mock_s3
+def test_get_function_by_arn():
+    bucket_name = "test-bucket"
+    s3_conn = boto3.client("s3", "us-east-1")
+    s3_conn.create_bucket(Bucket=bucket_name)
+
+    zip_content = get_test_zip_file2()
+    s3_conn.put_object(Bucket=bucket_name, Key="test.zip", Body=zip_content)
+    conn = boto3.client("lambda", "us-east-1")
+
+    fnc = conn.create_function(
+        FunctionName="testFunction",
+        Runtime="python2.7",
+        Role="test-iam-role",
+        Handler="lambda_function.lambda_handler",
+        Code={"S3Bucket": bucket_name, "S3Key": "test.zip"},
+        Description="test lambda function",
+        Timeout=3,
+        MemorySize=128,
+        Publish=True,
+    )
+
+    result = conn.get_function(FunctionName=fnc["FunctionArn"])
+    result["Configuration"]["FunctionName"].should.equal("testFunction")
+
+
 @mock_lambda
 @mock_s3
 def test_delete_function():
@@ -1322,6 +1355,7 @@ def test_update_configuration():
         Timeout=3,
         MemorySize=128,
         Publish=True,
+        Environment={"Variables": {"test_old_environment": "test_old_value"}},
     )
 
     assert fxn["Description"] == "test lambda function"
@@ -1336,6 +1370,7 @@ def test_update_configuration():
         Handler="lambda_function.new_lambda_handler",
         Runtime="python3.6",
         Timeout=7,
+        Environment={"Variables": {"test_environment": "test_value"}},
     )
 
     assert updated_config["ResponseMetadata"]["HTTPStatusCode"] == 200
@@ -1344,6 +1379,9 @@ def test_update_configuration():
     assert updated_config["MemorySize"] == 128
     assert updated_config["Runtime"] == "python3.6"
     assert updated_config["Timeout"] == 7
+    assert updated_config["Environment"]["Variables"] == {
+        "test_environment": "test_value"
+    }
 
 
 @mock_lambda