Add healthcheck to swag manager and implement on all backend types

swag_client/__about__.py

@@ -9,7 +9,7 @@
 __summary__ = ("Cloud multi-account metadata management tool.")
 __uri__ = "https://github.com/Netflix-Skunkworks/swag-client"
 
-__version__ = "0.3.3"
+__version__ = "0.3.4"
 
 __author__ = "The swag developers"
 __email__ = "oss@netflix.com"

swag_client/backend.py

@@ -50,6 +50,7 @@ def __init__(self, *args, **kwargs):
 
     def configure(self, *args, **kwargs):
         """Configures a SWAG manager. Overrides existing configuration."""
+
         self.version = kwargs['schema_version']
         self.namespace = kwargs['namespace']
         self.backend = get(kwargs['type'])(*args, **kwargs)
@@ -84,6 +85,10 @@ def get_all(self, search_filter=None):
 
         return items
 
+    def health_check(self):
+        """Fetch all data from backend."""
+        return self.backend.health_check()
+
     def get_service_enabled(self, name, accounts_list=None, search_filter=None, region=None):
         """Get a list of accounts where a service has been enabled."""
         if not accounts_list:

swag_client/backends/dynamodb.py

@@ -1,6 +1,7 @@
 import logging
 
 import boto3
+from botocore.exceptions import ClientError
 from dogpile.cache import make_region
 
 from swag_client.backend import SWAGManager
@@ -67,3 +68,15 @@ def get_all(self):
         ))
 
         return self.table.scan()['Items']
+
+    def health_check(self):
+        """Gets a single item to determine if Dynamo is functioning."""
+        logger.debug('Health Check on Table: {namespace}'.format(
+            namespace=self.namespace
+        ))
+
+        try:
+            self.table.scan(Limit=1)
+            return True
+        except ClientError as e:
+            logger.debug('Error encountered with Database.  Assume unhealthy')

swag_client/backends/file.py

@@ -109,3 +109,12 @@ def get_all(self):
         ))
 
         return load_file(self.data_file)
+
+
+    def health_check(self):
+        """Checks to make sure the file is there."""
+        logger.debug('Health Check on file for: {namespace}'.format(
+            namespace=self.namespace
+        ))
+
+        return os.path.isfile(self.data_file)

swag_client/backends/s3.py

@@ -127,3 +127,15 @@ def get_all(self):
         ))
 
         return load_file(self.client, self.bucket_name, self.data_file)
+
+    def health_check(self):
+        """Uses head object to make sure the file exists in S3."""
+        logger.debug('Health Check on S3 file for: {namespace}'.format(
+            namespace=self.namespace
+        ))
+
+        try:
+            self.client.head_object(Bucket=self.bucket_name, Key=self.data_file)
+            return True
+        except ClientError as e:
+            logger.debug('Error encountered with S3.  Assume unhealthy')