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):
@@ -47,36 +48,42 @@ 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'
-                sys.exit(1)
-            self.region = os.environ['SQS_REGION']
-            try:
-                self.sqs = boto.sqs.connect_to_region(self.region)
-            except NoAuthHandlerFound:
-                print 'ANSIBLE_ENABLE_SQS enabled but cannot connect ' \
-                      'to AWS due invalid credentials'
-                sys.exit(1)
-            if not 'SQS_NAME' in os.environ:
-                print 'ANSIBLE_ENABLE_SQS enabled but SQS_NAME not ' \
-                      'defined in environment'
-                sys.exit(1)
-            self.name = os.environ['SQS_NAME']
-            self.queue = self.sqs.create_queue(self.name)
-            if 'SQS_MSG_PREFIX' in os.environ:
-                self.prefix = os.environ['SQS_MSG_PREFIX']
-            else:
-                self.prefix = ''
-
-            self.last_seen_ts = {}
+        if not 'SQS_REGION' in os.environ:
+            print 'ANSIBLE_ENABLE_SQS enabled but SQS_REGION ' \
+                  'not defined in environment'
+            sys.exit(1)
+        self.region = os.environ['SQS_REGION']
+        try:
+            self.sqs = boto.sqs.connect_to_region(self.region)
+        except NoAuthHandlerFound:
+            print 'ANSIBLE_ENABLE_SQS enabled but cannot connect ' \
+                  'to AWS due invalid credentials'
+            sys.exit(1)
+        if not 'SQS_NAME' in os.environ:
+            print 'ANSIBLE_ENABLE_SQS enabled but SQS_NAME not ' \
+                  'defined in environment'
+            sys.exit(1)
+        self.name = os.environ['SQS_NAME']
+        self.queue = self.sqs.create_queue(self.name)
+        if 'SQS_MSG_PREFIX' in os.environ:
+            self.prefix = os.environ['SQS_MSG_PREFIX']
         else:
-            self.enable_sqs = False
+            self.prefix = ''
+
+        self.last_seen_ts = {}
 
     def runner_on_failed(self, host, res, ignore_errors=False):
         if self.enable_sqs: