OpenStack镜像服务（glance）允许用户发现、注册和恢复虚拟机镜像。Glance提供Rest API可以查询虚拟机镜像的metadata并且可以获取镜像。通过Glance，虚拟机镜像可以被存储到多种存储上，比如简单的文件存储或者对象存储（比如OpenStack中swift项目）。
一、OpenStack 镜像服务包含组件
                                    图1.1. OpenStack glance组件
 

二、OpenStack 镜像服务安装
    下面介绍如何安装和配置镜像服务，即glance。这个配置将镜像保存到本地文件系统中，默认存储在/var/lib/glance/p_w_picpaths/目录中。所有的步骤将在控制节点（Controller Node)上面进行操作。
1.安装前的准备
安装和配置镜像服务之前，必须创建数据库、服务证书和API端点。
1.1数据库配置
1）创建数据库

root@controller:~# mysql -uroot -p
MariaDB [(none)]> create database glance;
Query OK, 1 row affected (0.06 sec)

2）给数据库授权

MariaDB [(none)]> GRANT ALL PRIVILEGES ON glance.* TO 'glance'@'localhost' IDENTIFIED BY 'sfzhang1109';
Query OK, 0 rows affected (0.45 sec)
MariaDB [(none)]> GRANT ALL PRIVILEGES ON glance.* TO 'glance'@'%' IDENTIFIED BY 'sfzhang1109';
Query OK, 0 rows affected (0.00 sec)
MariaDB [(none)]> flush privileges;
Query OK, 0 rows affected (0.06 sec)

3）退出数据库客户端

MariaDB [(none)]> exit
Bye

1.2 导入admin身份凭证以便执行管理命令

root@controller:~# source admin-openrc.sh

1.3 创建服务证书
1）创建glance用户（密码:glance）

root@controller:~# openstack user create --password-prompt glance
User Password:
Repeat User Password:
+----------+----------------------------------+
| Field    | Value                            |
+----------+----------------------------------+
| email    | None                             |
| enabled  | True                             |
| id       | 8d333920d9df49af8d57910c3c18dcf8 |
| name     | glance                           |
| username | glance                           |
+----------+----------------------------------+

2）将glance用户和租户服务添加管理员角

root@controller:~# openstack role add --project service --user glance admin
+-------+----------------------------------+
| Field | Value                            |
+-------+----------------------------------+
| id    | 05616505a61c4aa78f43fba9e60ba7fc |
| name  | admin                            |
+-------+----------------------------------+

3）创建glance服务实体

root@controller:~# openstack service create --name glance --description "OpenStack Image service" p_w_picpath
+-------------+----------------------------------+
| Field       | Value                            |
+-------------+----------------------------------+
| description | OpenStack Image service          |
| enabled     | True                             |
| id          | e448c04b115a4cd3b745b70b17fa95b3 |
| name        | glance                           |
| type        | p_w_picpath                            |
+-------------+----------------------------------+

1.4 创建镜像服务API端点

root@controller:~# openstack endpoint create \--publicurl http://controller:9292 \--internalurl http://controller:9292 \--adminurl http://controller:9292 \--region RegionOne \p_w_picpath
+--------------+----------------------------------+
| Field        | Value                            |
+--------------+----------------------------------+
| adminurl     | http://controller:9292           |
| id           | aa4ac4216c7a41fd8452c7186c9493ac |
| internalurl  | http://controller:9292           |
| publicurl    | http://controller:9292           |
| region       | RegionOne                        |
| service_id   | e448c04b115a4cd3b745b70b17fa95b3 |
| service_name | glance                           |
| service_type | p_w_picpath                            |
+--------------+----------------------------------+

2.安装和配置镜像服务组件
2.1安装软件包

root@controller:~# apt-get install glance python-glanceclient

2.2编辑/etc/glance/glance-api.conf配置文件，完成下面的配置
1)在[database]部分配置数据库访问

[database]
…
connection = mysql://glance:sfzhang1109@controller/glance

2)在[keystone_authtoken] 和[paste_deploy]部分配置身份认证入口

[keystone_authtoken]
…
auth_uri = http://controller:5000
auth_url = http://controller:35357
auth_plugin = password
project_domain_id = default
user_domain_id = default
project_name = service
username = glance
password = glance
[paste_deploy]
…
flavor = keystone

3)在[glance_store]部分配置本地文件系统存储和镜像文件的位置

[glance_store]
...
default_store = file
filesystem_store_datadir = /data/glance/p_w_picpaths/

4)在[DEFAULT]部分禁用noop消息驱动，因为该选项只和可选的Telemetry服务有关

[DEFAULT]
...
notification_driver = noop

5)在[DEFAULT]部分开启详细日志配置，方便故障分析和排查

[DEFAULT]
...
verbose = True

2.3编辑/etc/glance/glance-registry.conf配置文件，完成下面的配置
1）在[database]部分配置数据库访问

connection = mysql://glance:sfzhang1109@controller/glance

2)在[keystone_authtoken] 和[paste_deploy]部分配置身份认证入口

[keystone_authtoken]
...
auth_uri = http://controller:5000
auth_url = http://controller:35357
auth_plugin = password
project_domain_id = default
user_domain_id = default
project_name = service
username = glance
password = glance

3)在[DEFAULT]部分禁用noop消息驱动，因为该选项只和可选的Telemetry服务有关

[paste_deploy]
...
flavor = keystone

4)在[DEFAULT]部分开启详细日志配置，方便故障分析和排查

[DEFAULT]
...
verbose = True

2.4 初始化镜像服务数据库

root@controller:~# su -s /bin/sh -c "glance-manage db_sync" glance
2015-09-01 06:17:25.166 18641 INFO migrate.versioning.api [-] 0 -> 1...
2015-09-01 06:17:25.193 18641 INFO glance.db.sqlalchemy.migrate_repo.schema [-] creating table p_w_picpaths
…

3.安装完成
1）重启Image service的服务

root@controller:~# service glance-registry restart
root@controller:~# service glance-api restart

2默认会创建SQLite数据库，因为使用的是MYSQL数据库，因此要删除QLite数据库文件
三、OpenStack Image service服务验证
1）配置镜像服务客户端使用API的版本为2.0

root@controller:~# echo "export OS_IMAGE_API_VERSION=2" | tee -a admin-openrc.sh demo-openrc.sh

2）执行admin身份凭证

root@controller:~# source admin-openrc.sh

3）在本地创建临时目录

root@controller:~# mkdir /tmp/p_w_picpaths

4）下载镜像到该目录

root@controller:~# wget -P /tmp/p_w_picpaths http://download.cirros-cloud.net/0.3.4/cirros-0.3.4-x86_64-disk.img

5）上传镜像到Image service,镜像格式为QCOW2。

root@controller:~# glance p_w_picpath-create --name "cirros-0.3.4-x86_64" --file /tmp/p_w_picpaths/cirros-0.3.4-x86_64-disk.img   --disk-format qcow2 --container-format bare  --progress
[=============================>] 100%
+------------------+--------------------------------------+
| Property         | Value                                |
+------------------+--------------------------------------+
| checksum         | ee1eca47dc88f4879d8a229cc70a07c6     |
| container_format | bare                                 |
| created_at       | 2015-09-11T07:04:31.000000           |
| deleted          | False                                |
| deleted_at       | None                                 |
| disk_format      | qcow2                                |
| id               | df54ff49-b167-4fed-987a-0ade3cbc9aca |
| is_public        | False                                |
| min_disk         | 0                                    |
| min_ram          | 0                                    |
| name             | cirros-0.3.4-x86_64                  |
| owner            | d04d4985d62f42e2af2ddc35f442ffd9     |
| protected        | False                                |
| size             | 13287936                             |
| status           | active                               |
| updated_at       | 2015-09-11T07:04:32.000000           |
| virtual_size     | None                                 |
+------------------+--------------------------------------+

6）确认镜像上传并验证属性

root@controller:~# glance p_w_picpath-list
+--------------------------------------+---------------------+-------------+------------------+----------+--------+
| ID                                   | Name                | Disk Format | Container Format | Size     | Status |
+--------------------------------------+---------------------+-------------+------------------+----------+--------+
| df54ff49-b167-4fed-987a-0ade3cbc9aca | cirros-0.3.4-x86_64 | qcow2       | bare             | 13287936 | active |
+--------------------------------------+---------------------+-------------+------------------+----------+--------+

7）删除临时目录的镜像文件

root@controller:~# rm -r /tmp/p_w_picpaths/

备注：

1）OpenStack官方文档：

http://docs.openstack.org/kilo/install-guide/install/apt/content/