SQS plugin: ignore import errors until we care about them

playbooks/callback_plugins/sqs.py

@@ -22,11 +22,12 @@ import time
 import json
 import socket
 try:
+    import boto
+except ImportError:
+    boto = None
+else:
     import boto.sqs
     from boto.exception import NoAuthHandlerFound
-except ImportError:
-    print "Boto is required for the sqs_notify callback plugin"
-    raise
 
 
 class CallbackModule(object):
@@ -47,11 +48,19 @@ class CallbackModule(object):
         - START events
     """
     def __init__(self):
+        self.enable_sqs = 'ANSIBLE_ENABLE_SQS' in os.environ
+        if not self.enable_sqs:
+            return
+
+        # make sure we got our imports
+        if not boto:
+            raise ImportError(
+                "The sqs callback module requires the boto Python module, "
+                "which is not installed or was not found."
+            )
 
         self.start_time = time.time()
 
-        if 'ANSIBLE_ENABLE_SQS' in os.environ:
-            self.enable_sqs = True
         if not 'SQS_REGION' in os.environ:
             print 'ANSIBLE_ENABLE_SQS enabled but SQS_REGION ' \
                   'not defined in environment'
@@ -75,8 +84,6 @@ class CallbackModule(object):
             self.prefix = ''
 
         self.last_seen_ts = {}
-        else:
-            self.enable_sqs = False
 
     def runner_on_failed(self, host, res, ignore_errors=False):
         if self.enable_sqs: