fetch ami id from ssm via cdk, with .string_value fix

cdk_app/hyp3_stack.py

@@ -2,6 +2,7 @@
 
 import aws_cdk as cdk
 from aws_cdk import cloudformation_include as cfn_inc
+from aws_cdk import aws_ssm as ssm
 from constructs import Construct
 
 
@@ -23,11 +24,7 @@ def __init__(self, scope: Construct, id: str, **kwargs) -> None:
             'ExpandedMaxvCpus': os.environ['EXPANDED_MAX_VCPUS'],
             'MonthlyBudget': os.environ['MONTHLY_BUDGET'],
             'RequiredSurplus': os.environ['REQUIRED_SURPLUS'],
-
-            # FIXME: retrieve AmiId from ssm parameter store
-            #'AmiId': os.environ['AMI_ID'],
-            'AmiId': 'ami-02a9aa9c17c6204ae',
-
+            'AmiId': ssm.StringParameter.from_string_parameter_name(self, 'AmiId', os.environ['AMI_ID']).string_value,
             'InstanceTypes': os.environ['INSTANCE_TYPES'].split(','),
         }
         if os.environ['SECURITY_ENVIRONMENT'] != 'EDC':