nuke_prefixed_buckets waits up to 60 seconds for object locks to expire

objects locked in GOVERNANCE mode can be removed with
BypassGovernanceRetention, but some tests may leave an object locked in
COMPLIANCE mode, which blocks deletion until the retention period
expires

nuke_prefixed_buckets now checks the retention policy of objects that it
fails to delete with AccessDenied, and will wait up to 60 seconds for
locks to expire before retrying the deletes. if the wait exceeds 60
seconds, it instead throws an error without deleting the bucket

instead of doing this in nuke_prefixed_buckets, we could potentially
have each object-lock test case handle this manually, but that would
add a separate delay to each test case

Signed-off-by: Casey Bodley <cbodley@redhat.com>

s3tests_boto3/functional/__init__.py

@@ -4,6 +4,8 @@ from botocore.client import Config
 from botocore.exceptions import ClientError
 from botocore.handlers import disable_signing
 import configparser
+import datetime
+import time
 import os
 import munch
 import random
@@ -101,10 +103,41 @@ def nuke_bucket(client, bucket):
 
     # list and delete objects in batches
     for objects in list_versions(client, bucket, batch_size):
-        client.delete_objects(Bucket=bucket,
+        delete = client.delete_objects(Bucket=bucket,
                 Delete={'Objects': objects, 'Quiet': True},
                 BypassGovernanceRetention=True)
 
+        # check for object locks on 403 AccessDenied errors
+        for err in delete.get('Errors', []):
+            if err.get('Code') != 'AccessDenied':
+                continue
+            try:
+                res = client.get_object_retention(Bucket=bucket,
+                        Key=err['Key'], VersionId=err['VersionId'])
+                retain_date = res['Retention']['RetainUntilDate']
+                if not max_retain_date or max_retain_date < retain_date:
+                    max_retain_date = retain_date
+            except ClientError:
+                pass
+
+    if max_retain_date:
+        # wait out the retention period (up to 60 seconds)
+        now = datetime.datetime.now(max_retain_date.tzinfo)
+        if max_retain_date > now:
+            delta = max_retain_date - now
+            if delta.total_seconds() > 60:
+                raise RuntimeError('bucket {} still has objects \
+locked for {} more seconds, not waiting for \
+bucket cleanup'.format(bucket, delta.total_seconds()))
+            print('nuke_bucket', bucket, 'waiting', delta.total_seconds(),
+                    'seconds for object locks to expire')
+            time.sleep(delta.total_seconds())
+
+        for objects in list_versions(client, bucket, batch_size):
+            client.delete_objects(Bucket=bucket,
+                    Delete={'Objects': objects, 'Quiet': True},
+                    BypassGovernanceRetention=True)
+
     client.delete_bucket(Bucket=bucket)
 
 def nuke_prefixed_buckets(prefix, client=None):