fix boto 2 conflict on Google Compute Engine instances

GCE installs some Python-2-only boto plugin that conflicts with boto running under Python 3. It gives a SyntaxError in /usr/share/google/boto/boto_plugins/compute_auth.py (https://github.com/GoogleCloudPlatform/compute-image-packages).

Disabling boto's default configuration file prior to importing boto so that GCE's plugin is not loaded.

See https://discourse.mailinabox.email/t/500-internal-server-error-for-admin/942.

CHANGELOG.md

@@ -22,6 +22,7 @@ System:
 * If ownCloud sends out email, it will use the box's administrative address now (admin@yourboxname).
 * Z-Push (Exchange/ActiveSync) logs now exclude warnings and are now rotated to save disk space.
 * Fix pip command that might have not installed all necessary Python packages.
+* The control panel and backup would not work on Google Compute Engine because they install a conflicting boto package.
 
 v0.14 (November 4, 2015)
 ------------------------

management/backup.py

@@ -12,7 +12,7 @@ import os, os.path, shutil, glob, re, datetime
 import dateutil.parser, dateutil.relativedelta, dateutil.tz
 import rtyaml
 
-from utils import exclusive_process, load_environment, shell, wait_for_service
+from utils import exclusive_process, load_environment, shell, wait_for_service, fix_boto
 
 def backup_status(env):
 	# Root folder
@@ -326,6 +326,7 @@ def list_target_files(config):
 
 	elif p.scheme == "s3":
 		# match to a Region
+		fix_boto() # must call prior to importing boto
 		import boto.s3
 		from boto.exception import BotoServerError
 		for region in boto.s3.regions():

management/daemon.py

@@ -94,6 +94,7 @@ def index():
 	no_users_exist = (len(get_mail_users(env)) == 0)
 	no_admins_exist = (len(get_admins(env)) == 0)
 
+	utils.fix_boto() # must call prior to importing boto
 	import boto.s3
 	backup_s3_hosts = [(r.name, r.endpoint) for r in boto.s3.regions()]
 

management/utils.py

@@ -245,6 +245,14 @@ def wait_for_service(port, public, env, timeout):
 				return False
 		time.sleep(min(timeout/4, 1))
 
+def fix_boto():
+	# Google Compute Engine instances install some Python-2-only boto plugins that
+	# conflict with boto running under Python 3. Disable boto's default configuration
+	# file prior to importing boto so that GCE's plugin is not loaded:
+	import os
+	os.environ["BOTO_CONFIG"] = "/etc/boto3.cfg"
+
+
 if __name__ == "__main__":
 	from dns_update import get_dns_domains
 	from web_update import get_web_domains, get_default_www_redirects