obsync: make obsync run without cloudfiles installed

Cloudfiles probably shouldn't be a requirement for running obsync, so this
commit makes it optional.

diff --git a/src/obsync/obsync b/src/obsync/obsync
index d4dc9ccd907bd4e7b1422f6801f1b039b5443d89..9536eab84db48c792f3a94e558b6ee96e08a3e8b 100755 (executable)
--- a/src/obsync/obsync
+++ b/src/obsync/obsync
@@ -23,7 +23,6 @@ from sys import stderr
 from lxml import etree
 import base64
 import boto
-import cloudfiles
 import errno
 import hashlib
 import mimetypes
@@ -38,6 +37,11 @@ import time
 import traceback
 import xattr
 
+try:
+    import cloudfiles
+except ImportError:
+    cloudfiles = None
+
 # Command-line options
 global opts
 
@@ -82,6 +86,9 @@ DST_CONSISTENCY   Set to 'eventual' if the destination is eventually consistent
 
 If these environment variables are not given, we will fall back on libboto
 defaults.
+
+Note: if python-cloudfiles is not installed, swift stores will not be able
+to be synced.
 """
 ###### Constants #######
 ACL_XATTR = "rados.acl"
@@ -1062,6 +1069,8 @@ try:
             if (not opts.src_host):
                 raise ObsyncArgumentParsingException("src-host is required for s3 stores!")
         if (opts.src_type == 'swift'):
+            if not cloudfiles:
+                raise ObsyncArgumentParsingException("cloudfiles library not found. Swift syncing unavailable")
             if (not opts.src_authurl):
                 raise ObsyncArgumentParsingException("src-authurl is required for swift stores!")
             if (opts.src_host):
@@ -1084,6 +1093,8 @@ try:
             if (not opts.dst_host):
                 raise ObsyncArgumentParsingException("dst-host is required for s3 stores!")
         if (opts.dst_type == 'swift'):
+            if not cloudfiles:
+                raise ObsyncArgumentParsingException("cloudfiles library not found. Swift syncing unavailable")
             if (not opts.dst_authurl):
                 raise ObsyncArgumentParsingException("dst-authurl is required for swift stores!")
             if (opts.dst_host):