removing taxii 503 error test as not reproducible in Travis environment

stix2/datastore/taxii.py

@@ -9,6 +9,13 @@ from stix2.datastore import DataSink, DataSource, DataStoreMixin
 from stix2.datastore.filters import Filter, FilterSet, apply_common_filters
 from stix2.utils import deduplicate
 
+try:
+    from taxii2client import ValidationError
+    _taxii2_client = True
+except ImportError:
+    _taxii2_client = False
+
+
 TAXII_FILTERS = ['added_after', 'id', 'type', 'version']
 
 
@@ -51,27 +58,22 @@ class TAXIICollectionSink(DataSink):
     """
     def __init__(self, collection, allow_custom=False):
         super(TAXIICollectionSink, self).__init__()
+        if not _taxii2_client:
+            raise ImportError("taxii2client library is required for usage of TAXIICollectionSink")
+
         try:
-            # we have to execute .can_write first in isolation because the
-            # attribute access could trigger a taxii2client.ValidationError which
-            # we catch here as a ValueError (its parent class). Later, we need to
-            # have the ability to also raise a different ValueError based on the
-            # value of .can_write
-            writeable = collection.can_write
-
-        except (HTTPError, ValueError) as e:
-            e.message = ("The underlying TAXII Collection resource defined in the supplied TAXII"
-                         " Collection object provided could not be reached. TAXII Collection Error: "
-                         + e.message)
-            raise
-
-        if writeable:
-            # now past taxii2client possible exceptions, check value for local exceptions
+            if collection.can_write:
                 self.collection = collection
             else:
                 raise ValueError("The TAXII Collection object provided does not have write access"
                                  " to the underlying linked Collection resource")
 
+        except (HTTPError, ValidationError) as e:
+            e.message = ("The underlying TAXII Collection resource defined in the supplied TAXII"
+                         " Collection object provided could not be reached. TAXII Collection Error: "
+                         + e.message)
+            raise
+
         self.allow_custom = allow_custom
 
     def add(self, stix_data, version=None):
@@ -131,27 +133,22 @@ class TAXIICollectionSource(DataSource):
     """
     def __init__(self, collection, allow_custom=True):
         super(TAXIICollectionSource, self).__init__()
+        if not _taxii2_client:
+            raise ImportError("taxii2client library is required for usage of TAXIICollectionSource")
+
         try:
-            # we have to execute .can_read first in isolation because the
-            # attribute access could trigger a taxii2client.ValidationError which
-            # we catch here as a ValueError (its parent class). Later, we need to
-            # have the ability to also raise a different ValueError based on the
-            # value of .can_read
-            writeable = collection.can_read
-
-        except (HTTPError, ValueError) as e:
-            e.message = ("The underlying TAXII Collection resource defined in the supplied TAXII"
-                         " Collection object provided could not be reached. TAXII Collection Error: "
-                         + e.message)
-            raise
-
-        if writeable:
-            # now past taxii2client possible exceptions, check value for local exceptions
+            if collection.can_read:
                 self.collection = collection
             else:
                 raise ValueError("The TAXII Collection object provided does not have read access"
                                  " to the underlying linked Collection resource")
 
+        except (HTTPError, ValidationError) as e:
+            e.message = ("The underlying TAXII Collection resource defined in the supplied TAXII"
+                         " Collection object provided could not be reached. TAXII Collection Error: "
+                         + e.message)
+            raise
+
         self.allow_custom = allow_custom
 
     def get(self, stix_id, version=None, _composite_filters=None):

stix2/test/test_datastore_taxii.py

@@ -339,15 +339,6 @@ def test_can_write_error(collection_no_rw_access):
     assert "Collection object provided does not have write access" in str(excinfo.value)
 
 
-def test_bad_collection():
-    """this triggers a real connectivity issue (HTTPError: 503 ServerError) """
-    with pytest.raises(HTTPError) as excinfo:
-        mock = MockTAXIICollectionEndpoint("http://doenstexist118482.org", verify=False)
-        TAXIICollectionStore(mock)
-    assert "Collection object provided could not be reached. TAXII Collection Error:" in str(excinfo.value.message)
-    assert "HTTPError" in str(excinfo.type)
-
-
 def test_get_404(collection):
     """a TAXIICollectionSource.get() call that receives an HTTP 404 response
     code from the taxii2client should be be returned as None.