Add option validation in cfncluster configure cli

I'm adding a flag to the prompt function of th easyconfig.py script
to check if the inserted value is one of the acceptable options.
It is important for region, key pair, vpc and subnet ids.

Signed-off-by: Enrico Usai <[email protected]>

Author: Enrico Usai

cli/cfncluster/easyconfig.py

@@ -27,7 +27,7 @@
 logger = logging.getLogger('cfncluster.cfncluster')
 unsupported_regions = ['ap-northeast-3', 'cn-north-1', 'cn-northwest-1']
 
-def prompt(prompt, default_value=None, hidden=False, options=None):
+def prompt(prompt, default_value=None, hidden=False, options=None, check_validity=False):
     if hidden and default_value is not None:
         user_prompt = prompt + ' [*******' + default_value[-4:] + ']: '
     else:
@@ -42,12 +42,17 @@ def prompt(prompt, default_value=None, hidden=False, options=None):
         for o in options:
             print('    %s' % o)
 
-    var = input(user_prompt)
+    var = input(user_prompt).strip()
 
     if var == '':
         return default_value
     else:
-        return var.strip()
+        if check_validity and options is not None and var not in options:
+            print('ERROR: The value (%s) is not valid ' % var)
+            print('Please select one of the Acceptable Values listed above.')
+            sys.exit(1)
+        else:
+            return var
 
 def get_regions():
     ec2 = boto3.client('ec2')
@@ -130,13 +135,13 @@ def configure(args):
     aws_secret_access_key = prompt('AWS Secret Access Key ID', config.get('aws', 'aws_secret_access_key') if config.has_option('aws', 'aws_secret_access_key') else None, True)
 
     # Use built in boto regions as an available option
-    aws_region_name = prompt('AWS Region ID', config.get('aws', 'aws_region_name') if config.has_option('aws', 'aws_region_name') else None, options=get_regions())
+    aws_region_name = prompt('AWS Region ID', config.get('aws', 'aws_region_name') if config.has_option('aws', 'aws_region_name') else None, options=get_regions(), check_validity=True)
     vpcname = prompt('VPC Name', config.get('cluster ' + cluster_template, 'vpc_settings') if config.has_option('cluster ' + cluster_template, 'vpc_settings') else 'public')
 
     # Query EC2 for available keys as options
-    key_name = prompt('Key Name', config.get('cluster ' + cluster_template, 'key_name') if config.has_option('cluster ' + cluster_template, 'key_name') else None, options=list_keys(aws_access_key_id, aws_secret_access_key, aws_region_name))
-    vpc_id = prompt('VPC ID', config.get('vpc ' + vpcname, 'vpc_id') if config.has_option('vpc ' + vpcname, 'vpc_id') else None, options=list_vpcs(aws_access_key_id, aws_secret_access_key, aws_region_name))
-    master_subnet_id = prompt('Master Subnet ID', config.get('vpc ' + vpcname, 'master_subnet_id') if config.has_option('vpc ' + vpcname, 'master_subnet_id') else None, options=list_subnets(aws_access_key_id, aws_secret_access_key, aws_region_name, vpc_id))
+    key_name = prompt('Key Name', config.get('cluster ' + cluster_template, 'key_name') if config.has_option('cluster ' + cluster_template, 'key_name') else None, options=list_keys(aws_access_key_id, aws_secret_access_key, aws_region_name), check_validity=True)
+    vpc_id = prompt('VPC ID', config.get('vpc ' + vpcname, 'vpc_id') if config.has_option('vpc ' + vpcname, 'vpc_id') else None, options=list_vpcs(aws_access_key_id, aws_secret_access_key, aws_region_name), check_validity=True)
+    master_subnet_id = prompt('Master Subnet ID', config.get('vpc ' + vpcname, 'master_subnet_id') if config.has_option('vpc ' + vpcname, 'master_subnet_id') else None, options=list_subnets(aws_access_key_id, aws_secret_access_key, aws_region_name, vpc_id), check_validity=True)
 
     # Dictionary of values we want to set
     s_global = { '__name__': 'global', 'cluster_template': cluster_template, 'update_check': 'true', 'sanity_check': 'true' }