External Ceph - Implementation Cinder

This patch adds support for external Ceph clusters for Cinder.

For clean integration the backend configuration mechanism had to be
slightly adjusted.

We now have the option to enable multiple backends for Cinder
independently.

Currently, the flags cinder_backend_iscsi and cinder_backend_ceph are
used to toggle backends.

Documentation on how to use external ceph was added.

Change-Id: I7e0267b90d62d6d881f24f063cdb894422ec8618
Partially-Implements: Blueprint: external-ceph

ansible/group_vars/all.yml

@@ -244,13 +244,15 @@ kibana_user: "kibana"
 
 
 #################################
-# Cinder - Block Storage options
+# Cinder options
 #################################
-cinder_volume_driver: "{{ 'ceph' if enable_ceph | bool else 'lvm' }}"
+cinder_backend_iscsi: "{{ enable_iscsi }}"
-cinder_volume_group: "{{ 'cinder-volumes' if enable_iscsi | bool else '' }}"
+cinder_backend_ceph: "{{ enable_ceph }}"
-cinder_volume_backend_name: "{{ 'cinder-volumes' if enable_iscsi | bool else '' }}"
+cinder_volume_driver: "{{ 'lvm' if cinder_backend_iscsi }}"
-cinder_iscsi_helper: "{{ 'tgtadm' if enable_iscsi | bool else '' }}"
+cinder_volume_group: "{{ 'cinder-volumes' if cinder_backend_iscsi | bool else '' }}"
-cinder_iscsi_protocol: "{{ 'iscsi' if enable_iscsi | bool else '' }}"
+cinder_volume_backend_name: "{{ 'cinder-volumes' if cinder_backend_iscsi | bool else '' }}"
+cinder_iscsi_helper: "{{ 'tgtadm' if cinder_backend_iscsi | bool else '' }}"
+cinder_iscsi_protocol: "{{ 'iscsi' if cinder_backend_iscsi | bool else '' }}"
 
 ###################
 # Ceph options

ansible/roles/cinder/tasks/bootstrap.yml

@@ -45,11 +45,11 @@
     action: "create_volume"
     common_options: "{{ docker_common_options }}"
     name: "cinder"
-  when: "{{ enable_iscsi | bool }}"
+  when: "{{ cinder_backend_iscsi | bool }}"
 
 - name: Creating iscsi info volume
   kolla_docker:
     action: "create_volume"
     common_options: "{{ docker_common_options }}"
     name: "iscsi_info"
-  when: "{{ enable_iscsi | bool }}"
+  when: "{{ cinder_backend_iscsi | bool }}"

ansible/roles/cinder/tasks/deploy.yml

@@ -1,13 +1,19 @@
 ---
 - include: ceph.yml
   when:
-    - enable_ceph | bool
+    - (enable_ceph | bool) and (cinder_backend_ceph | bool)
     - inventory_hostname in groups['ceph-mon'] or
         inventory_hostname in groups['cinder-api'] or
         inventory_hostname in groups['cinder-volume'] or
         inventory_hostname in groups['cinder-scheduler'] or
         inventory_hostname in groups['cinder-backup']
 
+- include: external_ceph.yml
+  when:
+    - (enable_ceph | bool == False) and (cinder_backend_ceph | bool)
+    - inventory_hostname in groups['cinder-volume'] or
+      inventory_hostname in groups['cinder-backup']
+
 - include: register.yml
   when: inventory_hostname in groups['cinder-api']
 

ansible/roles/cinder/tasks/external_ceph.yml

@@ -0,0 +1,36 @@
+---
+- name: Ensuring config directory exists
+  file:
+    path: "{{ node_config_directory }}/cinder-{{ item }}"
+    state: "directory"
+  when: inventory_hostname in groups['cinder-volume'] or
+        inventory_hostname in groups['cinder-backup']
+  with_items:
+    - volume
+    - backup
+
+- name: Copying over ceph.conf for Cinder
+  merge_configs:
+    vars:
+      service_name: "{{ item }}"
+    sources:
+      - "{{ node_custom_config }}/cinder/ceph.conf"
+      - "{{ node_custom_config }}/cinder/{{ item }}/ceph.conf"
+    dest: "{{ node_config_directory }}/{{ item }}/ceph.conf"
+  with_items:
+    - "cinder-backup"
+    - "cinder-volume"
+
+- name: Copy over Ceph keyring files for cinder-volume
+  copy:
+    src: "{{ item }}"
+    dest: "{{ node_config_directory }}/cinder-volume/"
+  with_fileglob:
+    - "{{ node_custom_config }}/cinder/cinder-volume/ceph.client*"
+
+- name: Copy over Ceph keyring files for cinder-backup
+  copy:
+    src: "{{ item }}"
+    dest: "{{ node_config_directory }}/cinder-backup/"
+  with_fileglob:
+    - "{{ node_custom_config }}/cinder/cinder-volume/ceph.client*"

ansible/roles/cinder/tasks/start.yml

@@ -30,8 +30,8 @@
       - "/etc/localtime:/etc/localtime:ro"
       - "/dev/:/dev/"
       - "/run/:/run/"
-      - "{% if enable_iscsi | bool %}cinder:/var/lib/cinder{% endif %}"
+      - "{% if cinder_backend_iscsi | bool %}cinder:/var/lib/cinder{% endif %}"
-      - "{% if enable_iscsi | bool %}iscsi_info:/etc/iscsi{% endif %}"
+      - "{% if cinder_backend_iscsi | bool %}iscsi_info:/etc/iscsi{% endif %}"
       - "kolla_logs:/var/log/kolla/"
 
 - name: Starting cinder-volume container

ansible/roles/cinder/templates/cinder-backup.json.j2

@@ -6,27 +6,13 @@
             "dest": "/etc/cinder/cinder.conf",
             "owner": "cinder",
             "perm": "0600"
-        },
+        }{% if cinder_backend_ceph | bool %},
         {
-            "source": "{{ container_config_directory }}/ceph.client.cinder-backup.keyring",
+            "source": "{{ container_config_directory }}/ceph.*",
-            "dest": "/etc/ceph/ceph.client.cinder-backup.keyring",
+            "dest": "/etc/ceph/",
             "owner": "cinder",
-            "perm": "0600",
+            "perm": "0700",
-            "optional": {{ (not enable_ceph | bool) | string | lower }}
+            "optional": {{ (not cinder_backend_ceph | bool) | string | lower }}
-        },
+        }{% endif %}
-        {
-            "source": "{{ container_config_directory }}/ceph.client.cinder.keyring",
-            "dest": "/etc/ceph/ceph.client.cinder.keyring",
-            "owner": "cinder",
-            "perm": "0600",
-            "optional": {{ (not enable_ceph | bool) | string | lower }}
-        },
-        {
-            "source": "{{ container_config_directory }}/ceph.conf",
-            "dest": "/etc/ceph/ceph.conf",
-            "owner": "cinder",
-            "perm": "0600",
-            "optional": {{ (not enable_ceph | bool) | string | lower }}
-        }
     ]
 }

ansible/roles/cinder/templates/cinder-volume.json.j2

@@ -6,20 +6,18 @@
             "dest": "/etc/cinder/cinder.conf",
             "owner": "cinder",
             "perm": "0600"
-        },
+        }{% if cinder_backend_ceph | bool %},
         {
-            "source": "{{ container_config_directory }}/ceph.client.cinder.keyring",
+            "source": "{{ container_config_directory }}/ceph.*",
-            "dest": "/etc/ceph/ceph.client.cinder.keyring",
+            "dest": "/etc/ceph/",
             "owner": "cinder",
-            "perm": "0600",
+            "perm": "0700"
-            "optional": {{ (not enable_ceph | bool) | string | lower }}
         },
         {
             "source": "{{ container_config_directory }}/ceph.conf",
             "dest": "/etc/ceph/ceph.conf",
             "owner": "cinder",
-            "perm": "0600",
+            "perm": "0600"
-            "optional": {{ (not enable_ceph | bool) | string | lower }}
+        }{% endif %}
-        }
     ]
 }

ansible/roles/cinder/templates/cinder.conf.j2

@@ -16,14 +16,14 @@ glance_api_version = 2
 
 os_region_name = {{ openstack_region_name }}
 
-{% if cinder_volume_driver == "lvm" %}
+{% if enable_ceph | bool and cinder_backend_ceph | bool %}
-enabled_backends = {{ cinder_volume_backend_name }}
-{% elif cinder_volume_driver == "ceph" %}
 default_volume_type = rbd-1
 enabled_backends = rbd-1
+{% elif cinder_backend_iscsi | bool %}
+enabled_backends = {{ cinder_volume_backend_name }}
 {% endif %}
 
-{% if service_name == "cinder-backup" and cinder_volume_driver == "ceph" %}
+{% if service_name == "cinder-backup" and enable_ceph | bool and cinder_backend_ceph | bool %}
 backup_driver = cinder.backup.drivers.ceph
 backup_ceph_conf = /etc/ceph/ceph.conf
 backup_ceph_user = cinder-backup
@@ -76,7 +76,7 @@ rabbit_ha_queues = true
 rabbit_hosts = {% for host in groups['rabbitmq'] %}{{ hostvars[host]['ansible_' + hostvars[host]['api_interface']]['ipv4']['address'] }}:{{ rabbitmq_port }}{% if not loop.last %},{% endif %}{% endfor %}
 
 
-{% if cinder_volume_driver == "lvm" %}
+{% if cinder_backend_iscsi | bool %}
 [{{ cinder_volume_backend_name }}]
 volume_group = {{ cinder_volume_group }}
 volume_driver = cinder.volume.drivers.lvm.LVMVolumeDriver
@@ -84,7 +84,8 @@ volume_backend_name = {{ cinder_volume_backend_name }}
 iscsi_ip_address = {{ hostvars[groups['tgtd'][0]]['ansible_' + hostvars[groups['tgtd'][0]]['storage_interface']]['ipv4']['address'] }}
 iscsi_helper = {{ cinder_iscsi_helper }}
 iscsi_protocol = {{ cinder_iscsi_protocol }}
-{% elif cinder_volume_driver == "ceph" %}
+
+{% elif enable_ceph | bool and cinder_backend_ceph | bool %}
 [rbd-1]
 volume_driver = cinder.volume.drivers.rbd.RBDDriver
 rbd_pool = {{ ceph_cinder_pool_name }}

doc/external-ceph-guide.rst

@@ -0,0 +1,153 @@
+.. _external-ceph-guide:
+
+=============
+External Ceph
+=============
+
+Sometimes it is necessary to connect OpenStack services to an existing Ceph
+cluster instead of deploying it with Kolla. This can be achieved with only a
+few configuration steps in Kolla.
+
+Requirements
+============
+
+* An existing installation of Ceph
+* Existing Ceph storage pools
+* Existing credentials in Ceph for OpenStack services to connect to Ceph
+(Glance, Cinder)
+
+Enabling External Ceph
+======================
+
+Using external Ceph with Kolla means not to deploy Ceph via Kolla. Therefore,
+disable Ceph deployment in ``/etc/kolla/global.yml``
+
+::
+
+  enable_ceph: "no"
+
+There are flags indicating individual services to use ceph or not which default
+to the value of ``enable_ceph``. Those flags now need to be activated in order
+to activate external Ceph integration. This can be done individually per
+service in ``/etc/kolla/global.yml``:
+
+::
+
+  glance_enable_ceph: "yes"
+  cinder_backend_ceph: "yes"
+
+The combination of ``enable_ceph: "no"`` and ``<service>_enable_ceph: "yes"``
+triggers the activation of external ceph mechanism in Kolla.
+
+Configuring External Ceph
+=========================
+
+Glance
+------
+
+Configuring Glance for Ceph includes three steps:
+
+1) Configure RBD backend in glance-api.conf
+2) Create Ceph configuration file in /etc/ceph/ceph.conf
+3) Create Ceph keyring file in /etc/ceph/ceph.client.<username>.keyring
+
+Step 1 is done by using Kolla's INI merge mechanism: Create a file in
+``/etc/kolla/config/glance/glance-api.conf`` with the following contents:
+
+::
+
+  [DEFAULT]
+  show_image_direct_url = True
+
+  [glance_store]
+  stores = rbd
+  default_store = rbd
+  rbd_store_chunk_size = 8
+  rbd_store_pool = images
+  rbd_store_user = glance
+  rbd_store_ceph_conf = /etc/ceph/ceph.conf
+  rados_connect_timeout = 0
+
+  [image_format]
+  container_formats = bare
+  disk_formats = raw
+
+Now put ceph.conf and the keyring file (name depends on the username created in
+Ceph) into the same directory, for example:
+
+/etc/kolla/config/glance/ceph.conf
+
+::
+
+  [global]
+  fsid = 1d89fec3-325a-4963-a950-c4afedd37fe3
+  mon_initial_members = ceph-0
+  mon_host = 192.168.0.56
+  auth_cluster_required = cephx
+  auth_service_required = cephx
+  auth_client_required = cephx
+
+/etc/kolla/config/glance/ceph.client.glance.keyring
+
+::
+
+  [client.glance]
+  key = AQAg5YRXS0qxLRAAXe6a4R1a15AoRx7ft80DhA==
+
+Kolla will pick up all files named ceph.* in this directory an copy them to the
+/etc/ceph/ directory of the container.
+
+Cinder
+------
+
+Configuring external Ceph for Cinder works very similar to
+Glance. The required Cinder configuration goes into
+/etc/kolla/config/cinder/cinder-volume.conf:
+
+::
+
+  [DEFAULT]
+  enabled_backends=rbd-1
+
+  [rbd-1]
+  rbd_ceph_conf=/etc/ceph/ceph.conf
+  rbd_user=cinder
+  backend_host=rbd:volumes
+  rbd_pool=volumes
+  volume_backend_name=rbd-1
+  volume_driver=cinder.volume.drivers.rbd.RBDDriver
+
+Next, place the ceph.conf file into
+/etc/kolla/config/cinder/ceph.conf:
+
+::
+
+  [global]
+  fsid = 1d89fec3-325a-4963-a950-c4afedd37fe3
+  mon_initial_members = ceph-0
+  mon_host = 192.168.0.56
+  auth_cluster_required = cephx
+  auth_service_required = cephx
+  auth_client_required = cephx
+
+Separate configuration options can be configured for
+cinder-volume and cinder-backup by adding ceph.conf files to
+/etc/kolla/config/cinder/cinder-volume and
+/etc/kolla/config/cinder/cinder-backup respectively. They
+will be merged with /etc/kolla/config/cinder/ceph.conf.
+
+Ceph keyrings are deployed per service and placed into
+cinder-volume and cinder-backup directories:
+
+::
+
+  root@deploy:/etc/kolla/config# cat
+  cinder/cinder-backup/ceph.client.cinder.keyring
+  [client.cinder]
+          key = AQAg5YRXpChaGRAAlTSCleesthCRmCYrfQVX1w==
+  root@deploy:/etc/kolla/config# cat
+  cinder/cinder-volume/ceph.client.cinder.keyring
+  [client.cinder]
+          key = AQAg5YRXpChaGRAAlTSCleesthCRmCYrfQVX1w==
+
+It is important that the files are named ceph.client*.

doc/index.rst

@@ -51,6 +51,7 @@ Kolla Services
    :maxdepth: 1
 
    ceph-guide
+   external-ceph-guide
    cinder-guide
    ironic-guide
    manila-guide

etc/kolla/globals.yml

@@ -129,6 +129,7 @@ neutron_external_interface: "eth1"
 # when ceph is not deployed by Kolla.
 #glance_enable_ceph: "{{ enable_ceph }}"
 
+
 ###################
 # Ceph options
 ###################
@@ -144,8 +145,12 @@ neutron_external_interface: "eth1"
 
 
 #######################
-# Cinder iSCSI options
+# Cinder options
 #######################
+# Enable / disable Cinder backends
+cinder_backend_iscsi: "{{ enable_iscsi }}"
+cinder_backend_ceph: "{{ enable_ceph }}"
+
 # Cinder's iSCSI backend !!!REQUIRES!!! two parameters:
 # 1 - IP address of the server hosting LVM Volume group
 # 2 - The name of Volume group which Cinder will use.