Improve Auto-Scaler: add extra configurations, key name and security group are now optional

examples/services/aws-autoscaler/aws_autoscaler.py

@@ -178,11 +178,9 @@ def run_wizard():
             ),
             "key_name": get_input(
                 "the Amazon Key Pair name",
-                required=True,
             ),
             "security_group_ids": input_list(
                 "Amazon Security Group ID",
-                required=True,
             ),
         }
 

trains/automation/aws_auto_scaler.py

@@ -5,15 +5,18 @@ import attr
 
 from .auto_scaler import AutoScaler
 from .. import Task
+from ..utilities.pyhocon import ConfigTree, ConfigFactory
 
 try:
     # noinspection PyPackageRequirements
     import boto3
 
-    Task.add_requirements('boto3')
+    Task.add_requirements("boto3")
 except ImportError:
-    raise ValueError("AwsAutoScaler requires 'boto3' package, it was not found\n"
+    raise ValueError(
-                     "install with: pip install boto3")
+        "AwsAutoScaler requires 'boto3' package, it was not found\n"
+        "install with: pip install boto3"
+    )
 
 
 class AwsAutoScaler(AutoScaler):
@@ -98,31 +101,41 @@ class AwsAutoScaler(AutoScaler):
             region_name=self.cloud_credentials_region,
         )
 
+        launch_specification = ConfigFactory.from_dict(
+            {
+                "ImageId": resource_conf["ami_id"],
+                "InstanceType": resource_conf["instance_type"],
+                "BlockDeviceMappings": [
+                    {
+                        "DeviceName": resource_conf["ebs_device_name"],
+                        "Ebs": {
+                            "VolumeSize": resource_conf["ebs_volume_size"],
+                            "VolumeType": resource_conf["ebs_volume_type"],
+                        },
+                    }
+                ],
+                "Placement": {"AvailabilityZone": resource_conf["availability_zone"]},
+            }
+        )
+        if resource_conf.get("key_name", None):
+            launch_specification["KeyName"] = resource_conf["key_name"]
+        if resource_conf.get("security_group_ids", None):
+            launch_specification["SecurityGroupIds"] = resource_conf[
+                "security_group_ids"
+            ]
+
         if resource_conf["is_spot"]:
             # Create a request for a spot instance in AWS
             encoded_user_data = base64.b64encode(user_data.encode("ascii")).decode(
                 "ascii"
             )
+            launch_specification["UserData"] = encoded_user_data
+            ConfigTree.merge_configs(
+                launch_specification, resource_conf.get("extra_configurations", {})
+            )
+
             instances = ec2.request_spot_instances(
-                LaunchSpecification={
+                LaunchSpecification=launch_specification
-                    "ImageId": resource_conf["ami_id"],
-                    "InstanceType": resource_conf["instance_type"],
-                    "KeyName": resource_conf["key_name"],
-                    "SecurityGroupIds": resource_conf["security_group_ids"],
-                    "Placement": {
-                        "AvailabilityZone": resource_conf["availability_zone"]
-                    },
-                    "UserData": encoded_user_data,
-                    "BlockDeviceMappings": [
-                        {
-                            "DeviceName": resource_conf["ebs_device_name"],
-                            "Ebs": {
-                                "VolumeSize": resource_conf["ebs_volume_size"],
-                                "VolumeType": resource_conf["ebs_volume_type"],
-                            },
-                        }
-                    ],
-                }
             )
 
             # Wait until spot request is fulfilled
@@ -137,25 +150,17 @@ class AwsAutoScaler(AutoScaler):
 
         else:
             # Create a new EC2 instance
-            instances = ec2.run_instances(
+            launch_specification.update(
-                ImageId=resource_conf["ami_id"],
                 MinCount=1,
                 MaxCount=1,
-                InstanceType=resource_conf["instance_type"],
-                KeyName=resource_conf["key_name"],
-                SecurityGroupIds=resource_conf["security_group_ids"],
                 UserData=user_data,
                 InstanceInitiatedShutdownBehavior="terminate",
-                BlockDeviceMappings=[
-                    {
-                        "DeviceName": resource_conf["ebs_device_name"],
-                        "Ebs": {
-                            "VolumeSize": resource_conf["ebs_volume_size"],
-                            "VolumeType": resource_conf["ebs_volume_type"],
-                        },
-                    }
-                ],
             )
+            ConfigTree.merge_configs(
+                launch_specification, resource_conf.get("extra_configurations", {})
+            )
+
+            instances = ec2.run_instances(**launch_specification)
 
             # Get the instance object for later use
             instance_id = instances["Instances"][0]["InstanceId"]

trains/utilities/wizard/user_input.py

@@ -79,7 +79,11 @@ def input_list(
     default=None,  # type: Optional[str]
     new_line=False,  # type: bool
 ):
-    res_list = [get_input(key, description, question, required, default, new_line)]
+    res = get_input(key, description, question, required, default, new_line)
+    if not res:
+        return None
+
+    res_list = [res]
     while input_bool("\nDefine another {}? [y/N]".format(key)):
         response = get_input(
                     key=key,