Make docker_storage_driver a str instead of enum

Allow any value to be passed on the docker_storage_driver field by turning it
into a StringField (was EnumField), and remove the constraints limiting the
values to 'devicemapper' and 'overlay'.

Change the docker storage setup to have a generic setup for all drivers with
the exception of 'devicemapper', which keeps its own specific storage config
function. For all others, do the same we already did for overlay (with two
cases for usage of a cinder volume or not) and simply set the storage driver
in the docker configuration to the value provided in the cluster template.

Change-Id: I9aa8f232ce64ece4d439c0a476f463820a499617
Closes-Bug: #1722522

23 files changed, 60 insertions, 69 deletions

diff --git a/api-ref/source/parameters.yaml b/api-ref/source/parameters.yaml
index 0d57506..d8d413a 100644
--- a/api-ref/source/parameters.yaml
+++ b/api-ref/source/parameters.yaml
@@ -225,8 +225,7 @@ dns_nameserver:
 docker_storage_driver:
   description: |
     The name of a driver to manage the storage for the images and the
-    container's writable layer. The supported drivers are ``devicemapper`` and
-    ``overlay``. The default is ``devicemapper``.
+    container's writable layer. The default is ``devicemapper``.
   in: body
   required: true
   type: string
diff --git a/doc/source/user/index.rst b/doc/source/user/index.rst
index 32dd190..f6c97d9 100644
--- a/doc/source/user/index.rst
+++ b/doc/source/user/index.rst
@@ -236,8 +236,7 @@ They are loosely grouped as: mandatory, infrastructure, COE specific.
 
 --docker-storage-driver \<docker-storage-driver\>
   The name of a driver to manage the storage for the images and the
-  container's writable layer.  The supported drivers are 'devicemapper'
-  and 'overlay'.  The default is 'devicemapper'.
+  container's writable layer. The default is 'devicemapper'.
 
 --labels \<KEY1=VALUE1,KEY2=VALUE2;KEY3=VALUE3...\>
   Arbitrary labels in the form of key=value pairs.  The accepted keys
@@ -1025,8 +1024,7 @@ Volume driver (volume-driver)
 
 Storage driver (docker-storage-driver)
   Specified in the ClusterTemplate to select the Docker storage driver.  The
-  supported storage drivers are 'devicemapper' and 'overlay', with
-  'devicemapper' being the default. Refer to the `Storage`_ section for more
+  default is 'devicemapper'. Refer to the `Storage`_ section for more
   details.
 
 Image (image)
@@ -1203,8 +1201,7 @@ Volume driver (volume-driver)
 
 Storage driver (docker-storage-driver)
   Specified in the ClusterTemplate to select the Docker storage driver.  The
-  supported storage driver are 'devicemapper' and 'overlay', with
-  'devicemapper' being the default. Refer to the `Storage`_ section for more
+  default is 'devicemapper'. Refer to the `Storage`_ section for more
   details.
 
 Image (image)
diff --git a/magnum/api/controllers/v1/baymodel.py b/magnum/api/controllers/v1/baymodel.py
index fb9b268..1b5c0e6 100644
--- a/magnum/api/controllers/v1/baymodel.py
+++ b/magnum/api/controllers/v1/baymodel.py
@@ -127,7 +127,7 @@ class BayModel(base.APIBase):
     insecure_registry = wtypes.StringType(min_length=1, max_length=255)
     """Insecure registry URL when creating a Baymodel"""
 
-    docker_storage_driver = wtypes.Enum(str, *fields.DockerStorageDriver.ALL)
+    docker_storage_driver = wtypes.StringType(min_length=1, max_length=255)
     """Docker storage driver"""
 
     master_lb_enabled = wsme.wsattr(types.boolean, default=False)
diff --git a/magnum/api/controllers/v1/cluster_template.py b/magnum/api/controllers/v1/cluster_template.py
index cc95bfc..fe0d942 100644
--- a/magnum/api/controllers/v1/cluster_template.py
+++ b/magnum/api/controllers/v1/cluster_template.py
@@ -128,7 +128,7 @@ class ClusterTemplate(base.APIBase):
     insecure_registry = wtypes.StringType(min_length=1, max_length=255)
     """Insecure registry URL when creating a ClusterTemplate """
 
-    docker_storage_driver = wtypes.Enum(str, *fields.DockerStorageDriver.ALL)
+    docker_storage_driver = wtypes.StringType(min_length=1, max_length=255)
     """Docker storage driver"""
 
     master_lb_enabled = wsme.wsattr(types.boolean, default=False)
diff --git a/magnum/db/sqlalchemy/alembic/versions/04c625aa95ba_change_storage_driver_to_string.py b/magnum/db/sqlalchemy/alembic/versions/04c625aa95ba_change_storage_driver_to_string.py
new file mode 100644
index 0000000..4a53f32
--- /dev/null
+++ b/magnum/db/sqlalchemy/alembic/versions/04c625aa95ba_change_storage_driver_to_string.py
@@ -0,0 +1,33 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+"""change storage driver to string
+
+Revision ID: 04c625aa95ba
+Revises: 52bcaf58fecb
+Create Date: 2017-10-10 15:40:37.553288
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '04c625aa95ba'
+down_revision = '52bcaf58fecb'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.alter_column('cluster_template', 'docker_storage_driver',
+                    existing_type=sa.Enum('devicemapper', 'overlay',
+                                          name='docker_storage_driver'),
+                    type_=sa.String(length=512),
+                    nullable=True)
diff --git a/magnum/drivers/common/templates/fragments/configure-docker-storage.sh b/magnum/drivers/common/templates/fragments/configure-docker-storage.sh
index 4704e07..87b8038 100644
--- a/magnum/drivers/common/templates/fragments/configure-docker-storage.sh
+++ b/magnum/drivers/common/templates/fragments/configure-docker-storage.sh
@@ -32,14 +32,8 @@ fi
 
 $configure_docker_storage_driver
 
-if [ "$DOCKER_STORAGE_DRIVER" = "overlay" ]; then
-    if [ $(echo -e "$(uname -r)\n3.18" | sort -V | head -1) = $(uname -r) ]; then
-        ERROR_MESSAGE="OverlayFS requires at least Linux kernel 3.18. Cluster node kernel version: $(uname -r)"
-        echo "ERROR: ${ERROR_MESSAGE}" >&2
-        sh -c "${WAIT_CURL} --data-binary '{\"status\": \"FAILURE\", \"reason\": \"${ERROR_MESSAGE}\"}'"
-    else
-        configure_overlay
-    fi
-else
+if [ "$DOCKER_STORAGE_DRIVER" = "devicemapper" ]; then
     configure_devicemapper
+else
+    configure_storage_driver_generic $DOCKER_STORAGE_DRIVER
 fi
diff --git a/magnum/drivers/common/templates/fragments/configure_docker_storage_driver_atomic.sh b/magnum/drivers/common/templates/fragments/configure_docker_storage_driver_atomic.sh
index 9d92a66..a06cccc 100644
--- a/magnum/drivers/common/templates/fragments/configure_docker_storage_driver_atomic.sh
+++ b/magnum/drivers/common/templates/fragments/configure_docker_storage_driver_atomic.sh
@@ -1,5 +1,5 @@
 # This file contains docker storage drivers configuration for fedora
-# atomic hosts. Currently, devicemapper and overlay are supported.
+# atomic hosts, as supported by Magnum.
 
 # * Remove any existing docker-storage configuration. In case of an
 #   existing configuration, docker-storage-setup will fail.
@@ -17,8 +17,8 @@ clear_docker_storage () {
     fi
 }
 
-# Configure docker storage with xfs as backing filesystem.
-configure_overlay () {
+# Configure generic docker storage driver.
+configure_storage_driver_generic() {
     clear_docker_storage
 
     if [ -n "$DOCKER_VOLUME_SIZE" ] && [ "$DOCKER_VOLUME_SIZE" -gt 0 ]; then
@@ -27,9 +27,7 @@ configure_overlay () {
         mount -a
     fi
 
-    echo "STORAGE_DRIVER=overlay" > /etc/sysconfig/docker-storage-setup
-
-    docker-storage-setup
+    sed -i "/^DOCKER_STORAGE_OPTIONS=/ s/=.*/=-s $1/" /etc/sysconfig/docker-storage
 
     local lvname=$(lvdisplay | grep "LV\ Path" | awk '{print $3}')
     local pvname=$(pvdisplay | grep "PV\ Name" | awk '{print $3}')
diff --git a/magnum/drivers/k8s_fedora_atomic_v1/templates/kubecluster.yaml b/magnum/drivers/k8s_fedora_atomic_v1/templates/kubecluster.yaml
index 8a05721..a87183b 100644
--- a/magnum/drivers/k8s_fedora_atomic_v1/templates/kubecluster.yaml
+++ b/magnum/drivers/k8s_fedora_atomic_v1/templates/kubecluster.yaml
@@ -153,8 +153,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   wait_condition_timeout:
     type: number
diff --git a/magnum/drivers/k8s_fedora_atomic_v1/templates/kubemaster.yaml b/magnum/drivers/k8s_fedora_atomic_v1/templates/kubemaster.yaml
index 6bdc0ac..335fae7 100644
--- a/magnum/drivers/k8s_fedora_atomic_v1/templates/kubemaster.yaml
+++ b/magnum/drivers/k8s_fedora_atomic_v1/templates/kubemaster.yaml
@@ -60,8 +60,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   volume_driver:
     type: string
diff --git a/magnum/drivers/k8s_fedora_atomic_v1/templates/kubeminion.yaml b/magnum/drivers/k8s_fedora_atomic_v1/templates/kubeminion.yaml
index 53ef59d..d299fbe 100644
--- a/magnum/drivers/k8s_fedora_atomic_v1/templates/kubeminion.yaml
+++ b/magnum/drivers/k8s_fedora_atomic_v1/templates/kubeminion.yaml
@@ -50,8 +50,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   tls_disabled:
     type: boolean
diff --git a/magnum/drivers/k8s_fedora_ironic_v1/templates/kubecluster.yaml b/magnum/drivers/k8s_fedora_ironic_v1/templates/kubecluster.yaml
index 0225633..7368159 100644
--- a/magnum/drivers/k8s_fedora_ironic_v1/templates/kubecluster.yaml
+++ b/magnum/drivers/k8s_fedora_ironic_v1/templates/kubecluster.yaml
@@ -151,8 +151,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   wait_condition_timeout:
     type: number
diff --git a/magnum/drivers/k8s_fedora_ironic_v1/templates/kubemaster.yaml b/magnum/drivers/k8s_fedora_ironic_v1/templates/kubemaster.yaml
index 43b987d..e496523 100644
--- a/magnum/drivers/k8s_fedora_ironic_v1/templates/kubemaster.yaml
+++ b/magnum/drivers/k8s_fedora_ironic_v1/templates/kubemaster.yaml
@@ -49,8 +49,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   flannel_network_cidr:
     type: string
diff --git a/magnum/drivers/k8s_fedora_ironic_v1/templates/kubeminion_software_configs.yaml b/magnum/drivers/k8s_fedora_ironic_v1/templates/kubeminion_software_configs.yaml
index 0c7bd45..8b7d006 100644
--- a/magnum/drivers/k8s_fedora_ironic_v1/templates/kubeminion_software_configs.yaml
+++ b/magnum/drivers/k8s_fedora_ironic_v1/templates/kubeminion_software_configs.yaml
@@ -22,8 +22,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   tls_disabled:
     type: boolean
diff --git a/magnum/drivers/swarm_fedora_atomic_v1/templates/cluster.yaml b/magnum/drivers/swarm_fedora_atomic_v1/templates/cluster.yaml
index aacafda..103e8ef 100644
--- a/magnum/drivers/swarm_fedora_atomic_v1/templates/cluster.yaml
+++ b/magnum/drivers/swarm_fedora_atomic_v1/templates/cluster.yaml
@@ -144,8 +144,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   loadbalancing_protocol:
     type: string
diff --git a/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmmaster.yaml b/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmmaster.yaml
index c535676..a8f0407 100644
--- a/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmmaster.yaml
+++ b/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmmaster.yaml
@@ -29,8 +29,6 @@ parameters:
   docker_storage_driver:
     type: string
     description: docker storage driver name
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   external_network:
     type: string
diff --git a/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmnode.yaml b/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmnode.yaml
index d4562e1..3d4dd64 100644
--- a/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmnode.yaml
+++ b/magnum/drivers/swarm_fedora_atomic_v1/templates/swarmnode.yaml
@@ -38,8 +38,6 @@ parameters:
   docker_storage_driver:
     type: string
     description: docker storage driver name
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   external_network:
     type: string
diff --git a/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmcluster.yaml b/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmcluster.yaml
index 9687836..55de329 100644
--- a/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmcluster.yaml
+++ b/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmcluster.yaml
@@ -116,8 +116,6 @@ parameters:
     type: string
     description: docker storage driver name
     default: "devicemapper"
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   loadbalancing_protocol:
     type: string
diff --git a/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmmaster.yaml b/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmmaster.yaml
index 8f8d6ff..cd7e675 100644
--- a/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmmaster.yaml
+++ b/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmmaster.yaml
@@ -30,8 +30,6 @@ parameters:
   docker_storage_driver:
     type: string
     description: docker storage driver name
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   external_network:
     type: string
diff --git a/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmnode.yaml b/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmnode.yaml
index c0c362a..a205833 100644
--- a/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmnode.yaml
+++ b/magnum/drivers/swarm_fedora_atomic_v2/templates/swarmnode.yaml
@@ -38,8 +38,6 @@ parameters:
   docker_storage_driver:
     type: string
     description: docker storage driver name
-    constraints:
-      - allowed_values: ["devicemapper", "overlay"]
 
   external_network:
     type: string
diff --git a/magnum/objects/cluster_template.py b/magnum/objects/cluster_template.py
index ecaff18..955536d 100644
--- a/magnum/objects/cluster_template.py
+++ b/magnum/objects/cluster_template.py
@@ -41,7 +41,8 @@ class ClusterTemplate(base.MagnumPersistentObject, base.MagnumObject,
     # Version 1.15: Added 'floating_ip_enabled' field
     # Version 1.16: Renamed the class from "BayModel' to 'ClusterTemplate'
     # Version 1.17: 'coe' field type change to ClusterTypeField
-    VERSION = '1.17'
+    # Version 1.18: DockerStorageDriver is a StringField (was an Enum)
+    VERSION = '1.18'
 
     dbapi = dbapi.get_instance()
 
@@ -63,8 +64,7 @@ class ClusterTemplate(base.MagnumPersistentObject, base.MagnumObject,
         'volume_driver': fields.StringField(nullable=True),
         'apiserver_port': fields.IntegerField(nullable=True),
         'docker_volume_size': fields.IntegerField(nullable=True),
-        'docker_storage_driver': m_fields.DockerStorageDriverField(
-            nullable=True),
+        'docker_storage_driver': fields.StringField(nullable=True),
         'cluster_distro': fields.StringField(nullable=True),
         'coe': m_fields.ClusterTypeField(nullable=True),
         'http_proxy': fields.StringField(nullable=True),
diff --git a/magnum/objects/fields.py b/magnum/objects/fields.py
index 559a4e8..9024ef3 100644
--- a/magnum/objects/fields.py
+++ b/magnum/objects/fields.py
@@ -72,18 +72,6 @@ class ClusterType(fields.Enum):
         super(ClusterType, self).__init__(valid_values=ClusterType.ALL)
 
 
-class DockerStorageDriver(fields.Enum):
-    ALL = (
-        DEVICEMAPPER, OVERLAY,
-    ) = (
-        'devicemapper', 'overlay',
-    )
-
-    def __init__(self):
-        super(DockerStorageDriver, self).__init__(
-            valid_values=DockerStorageDriver.ALL)
-
-
 class QuotaResourceName(fields.Enum):
     ALL = (
         CLUSTER,
@@ -156,9 +144,5 @@ class ClusterTypeField(fields.BaseEnumField):
     AUTO_TYPE = ClusterType()
 
 
-class DockerStorageDriverField(fields.BaseEnumField):
-    AUTO_TYPE = DockerStorageDriver()
-
-
 class ServerTypeField(fields.BaseEnumField):
     AUTO_TYPE = ServerType()
diff --git a/magnum/tests/unit/objects/test_objects.py b/magnum/tests/unit/objects/test_objects.py
index 0f9c3de..16d1f5c 100644
--- a/magnum/tests/unit/objects/test_objects.py
+++ b/magnum/tests/unit/objects/test_objects.py
@@ -356,7 +356,7 @@ class TestObject(test_base.TestCase, _TestObject):
 # http://docs.openstack.org/developer/magnum/objects.html
 object_data = {
     'Cluster': '1.16-7a544c5059697c464810470980f81ba1',
-    'ClusterTemplate': '1.17-f1ce5212b46506360b41ab5cb7658af4',
+    'ClusterTemplate': '1.18-7fa94f4fdd027acfb4f022f202afdfb5',
     'Certificate': '1.1-1924dc077daa844f0f9076332ef96815',
     'MyObj': '1.0-34c4b1aadefd177b13f9a2f894cc23cd',
     'X509KeyPair': '1.2-d81950af36c59a71365e33ce539d24f9',
diff --git a/releasenotes/notes/bug-1722522-d94743c6362a5e48.yaml b/releasenotes/notes/bug-1722522-d94743c6362a5e48.yaml
new file mode 100644
index 0000000..b4164ff
--- /dev/null
+++ b/releasenotes/notes/bug-1722522-d94743c6362a5e48.yaml
@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    Allow any value to be passed on the docker_storage_driver field by turning it
+    into a StringField (was EnumField), and remove the constraints limiting the
+    values to 'devicemapper' and 'overlay'.
+upgrade:
+  - |
+    Requires a db upgrade to change the docker_storage_driver
+    field to be a string instead of an enum.