feat(controller): disable swap if there's a mem limit

Author: mboersma

controller/deis/settings.py

@@ -5,6 +5,7 @@
 from __future__ import unicode_literals
 import os.path
 import random
+import semantic_version as semver
 import string
 import sys
 import tempfile
@@ -372,6 +373,17 @@
     sys.path.append('/templates')
     from confd_settings import *  # noqa
 
+# Disable swap when mem limits are set, unless Docker is too old
+DISABLE_SWAP = '--memory-swap=-1'
+try:
+    version = 'unknown'
+    from registry.dockerclient import DockerClient
+    version = DockerClient().client.version().get('Version')
+    if not semver.validate(version) or semver.Version(version) < semver.Version('1.5.0'):
+        DISABLE_SWAP = ''
+except:
+    print("Not disabling --memory-swap for Docker version {}".format(version))
+
 # LDAP Backend Configuration
 # Should be always after the confd_settings import.
 LDAP_USER_SEARCH = LDAPSearch(

controller/requirements.txt

@@ -10,12 +10,13 @@ django-auth-ldap==1.2.5
 djangorestframework==3.0.5
 docker-py==1.5.0
 gunicorn==19.3.0
+marathon==0.6.15
 paramiko==1.15.2
 psycopg2==2.6.1
 python-etcd==0.3.2
+python-ldap==2.4.19
 PyYAML==3.11
+semantic_version==2.4.2
 simpleflock==0.0.2
-static==1.1.1
 South==1.0.2
-python-ldap==2.4.19
-marathon==0.6.15
+static==1.1.1

controller/scheduler/fleet.py

@@ -127,7 +127,7 @@ def _create_container(self, name, image, command, unit, **kwargs):
         # prepare memory limit for the container type
         mem = kwargs.get('memory', {}).get(l['c_type'], None)
         if mem:
-            l.update({'memory': '-m {}'.format(mem.lower())})
+            l.update({'memory': '-m {} {}'.format(mem.lower(), settings.DISABLE_SWAP)})
         else:
             l.update({'memory': ''})
         # prepare memory limit for the container type

docs/docs_requirements.txt

@@ -16,6 +16,7 @@ gunicorn==19.3.0
 paramiko==1.15.2
 python-etcd==0.3.2
 PyYAML==3.11
+semantic_version==2.4.2
 simpleflock==0.0.2
 South==1.0.2