openstack学习笔记之四：glance简介与手动安装部署

1、glance架构

glance的架构如图1-1所示。

图1-1 glance的架构

图1-2 openstack官方文档中的glance架构图
1)镜像服务组件：
 Glance-api：是一个对外的API接口，能够接受外部的API镜像请求。主要用于分析、分发、响应各种镜像管理的REST Request，然后通过其他模块(EG. glance-registry、Store Backend后端存储接口)完成镜像的发现、获取、存储等操作。默认绑定端口是9292。
Glance提供REST API来支持以下镜像操作：查询、注册、上传、获取、删除、访问权限管理
 glance-registry：用于存储、处理、获取Image Metadata。通过响应从glance-api发送过来的Image Metadata REST Request，然后与MySQL进行交互，实现Image Metadate的存储、处理、获取。默认绑定的端口是9191。
 glance-db：在Openstack中使用MySQL来支撑，用于存放Image Metadata。
 Image Metadate(镜像元数据)：指通过glance-registry来保存在MySQL Database； image 的chunk 数据 通过 glance-store 存放在各种 backend store 中，并从中获取。
 Glance Store：用于存储镜像文件。通过Store Backend后端存储接口来与glance-api联系。通过这个接口，glance可以从Image Store获取镜像文件再交由Nova用于创建虚拟机。
 Glance 通过Store Adapter(存储适配器)支持多种Imange Store方案
支持swift、file system、s3、sheepdog、rbd、cinder等。
2)image 的 访问权限分为：
public 公共的：可以被所有的 tenant 使用。
private 私有的/项目的：只能被 image owner 所在的 tenant 使用。
shared 共享的：一个非共有的image 可以共享给另外的 tenant，可通过member-* 操作来实现。
protected 受保护的：protected 的 image 不能被删除。

3)image 的各种状态
queued：没有上传 image 数据，只有db 中的元数据。
saving：正在上传 image data
active：正常状态
deleted/pending_delete： 已删除/等待删除
killed：image 元数据不正确，等待被删除。

2、Glance支持的Image格式

 raw – 非结构化的镜像格式
 vhd – 一种通用的虚拟机磁盘格式， 可用于Vmware、Xen、Microsoft Virtual PC/Virtual Server/Hyper-V、VirtualBox等
 vmdk – Vmware的虚拟机磁盘格式， 同样也支持多种Hypervisor
 vdi – VirtualBox、QEMU等支持的虚拟机磁盘格式
 qcow2 – 一种支持QEMU并且可以动态扩展的磁盘格式
 aki – Amazon Kernel 镜像
 ari – Amazon Ramdisk 镜像
 ami – Amazon 虚拟机镜像

3、常见面试题

1）、openstack对接ceph集群，image使用哪种格式？
答：使用raw格式。

---

2）、raw与qcow2的区别：
答：
(1)空间占用区别，如指定空间20G，实际仅用5G时，raw对外显示为20G，而qcow2对外则显示真实的大小5G，从节省空间大小来看使用qcow2；
(2)如果使用ceph使用raw格式，它对raw格式的兼容性更好，即使指定为qcow2格式，后端也会先转换成raw格式。

---

4、glance组件的工作过程

5、实战： glance的手动搭建

5.1、控制节点的安装配置

（1）创建glance数据库：

[root@controller ~]# mysql  -uroot -popenstack <

（2）创建glance用户，并在service项目中添加管理员角色

[root@controller ~]# source admin_openrc 
下面这句要分开执行，要输入glance用户的密码：
[root@controller ~]# openstack user create --domain default --password-prompt glance
User Password:
Repeat User Password:
+---------------------+----------------------------------+
| Field               | Value                            |
+---------------------+----------------------------------+
| domain_id           | default                          |
| enabled             | True                             |
| id                  | cd90f56cf9bc4c8f8a01f88c5c179762 |
| name                | glance                           |
| options             | {}                               |
| password_expires_at | None                             |
+---------------------+----------------------------------+
[root@controller ~]# openstack role add --project service --user glance admin

（3）创建glance服务及端口

[root@controller ~]# openstack service create --name glance --description "OpenStack Image" image
+-------------+----------------------------------+
| Field       | Value                            |
+-------------+----------------------------------+
| description | OpenStack Image                  |
| enabled     | True                             |
| id          | ad61f9ee483e4bea9cb374796f097dd3 |
| name        | glance                           |
| type        | image                            |
+-------------+----------------------------------+
[root@controller ~]# openstack endpoint create --region RegionOne  image public http://controller:9292
+--------------+----------------------------------+
| Field        | Value                            |
+--------------+----------------------------------+
| enabled      | True                             |
| id           | b781cb1117f040f1a18615b649fb5388 |
| interface    | public                           |
| region       | RegionOne                        |
| region_id    | RegionOne                        |
| service_id   | ad61f9ee483e4bea9cb374796f097dd3 |
| service_name | glance                           |
| service_type | image                            |
| url          | http://controller:9292           |
+--------------+----------------------------------+
[root@controller ~]# openstack endpoint create --region RegionOne  image internal http://controller:9292 
+--------------+----------------------------------+
| Field        | Value                            |
+--------------+----------------------------------+
| enabled      | True                             |
| id           | 129da42ca64c4cfb821afcf3c2e81dfd |
| interface    | internal                         |
| region       | RegionOne                        |
| region_id    | RegionOne                        |
| service_id   | ad61f9ee483e4bea9cb374796f097dd3 |
| service_name | glance                           |
| service_type | image                            |
| url          | http://controller:9292           |
+--------------+----------------------------------+
[root@controller ~]# openstack endpoint create --region RegionOne  image admin http://controller:9292
+--------------+----------------------------------+
| Field        | Value                            |
+--------------+----------------------------------+
| enabled      | True                             |
| id           | 9fc675719b1d49a48851abeee9f2622c |
| interface    | admin                            |
| region       | RegionOne                        |
| region_id    | RegionOne                        |
| service_id   | ad61f9ee483e4bea9cb374796f097dd3 |
| service_name | glance                           |
| service_type | image                            |
| url          | http://controller:9292           |
+--------------+----------------------------------+
[root@controller ~]# openstack endpoint list
---------+-----------+-----------------------------+
| ID                               | Region    | Service Name | Service Type | Enabled | Interface | URL                         |
---------+-----------+-----------------------------+
| 01ccfab5acb0407888620ca056f93dfe | RegionOne | keystone     | identity     | True    | admin     | http://controller:35357/v3/ |
| 129da42ca64c4cfb821afcf3c2e81dfd | RegionOne | glance       | image        | True    | internal  | http://controller:9292      |
| 4c2bd465260043039bcf7bf78776dd6b | RegionOne | keystone     | identity     | True    | internal  | http://controller:5000/v3/  |
| 9cd64dded6014abea4936800d3fd614c | RegionOne | glance       | image        | True    | public    | http://controller:9292      |
| 9fc675719b1d49a48851abeee9f2622c | RegionOne | glance       | image        | True    | admin     | http://controller:9292      |
| bdc34c7c99bb432eb13fa83a45d0065e | RegionOne | keystone     | identity     | True    | public    | http://controller:5000/v3/  |
+----------------------------------+-----------+--------------+--------------+---------+-----------+-----------------------------+
操作删除endpoint命令
[root@controller ~]# openstack endpoint delete IDNAME

（4）控制节点安装相关包并配置

[root@controller ~]# yum -y install openstack-glance 
[root@controller ~]# vim /etc/glance/glance-api.conf 
[database]
connection = mysql+pymysql://glance:openstack@controller/glance

[keystone_authtoken]
auth_uri = http://controller:5000     内部端口
auth_url = http://controller:35357     管理员端口
memcached_servers = controller:11211
auth_type = password
project_domain_name = default
user_domain_name = default
project_name = service
username = glance
password = openstack

[paste_deploy] (开启如下配置)
flavor = keystone

[glance_store] (开启如下配置)
stores = file,http 
default_store = file 
filesystem_store_datadir = /var/lib/glance/images/
[root@controller ~]# egrep -v "^#|^$" /etc/glance/glance-api.conf
[root@controller ~]# vim /etc/glance/glance-registry.conf 
[database] 
connection = mysql+pymysql://glance:openstack@controller/glance

[keystone_authtoken]
auth_uri = http://controller:5000
auth_url = http://controller:35357
memcached_servers = controller:11211
auth_type = password
project_domain_name = default
user_domain_name = default
project_name = service
username = glance
password = openstack

[paste_deploy]
flavor = keystone
[root@controller ~]# egrep -v "^#|^$" /etc/glance/glance-registry.conf

（5）初始化数据库表结构

[root@controller ~]# su -s /bin/sh -c "glance-manage db_sync" glance
/usr/lib/python2.7/site-packages/oslo_db/sqlalchemy/enginefacade.py:1336: OsloDBDeprecationWarning: EngineFacade is deprecated; please use oslo_db.sqlalchemy.enginefacade
  expire_on_commit=expire_on_commit, _conf=conf)
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade  -> liberty, liberty initial
INFO  [alembic.runtime.migration] Running upgrade liberty -> mitaka01, add index on created_at and updated_at columns of 'images' table
INFO  [alembic.runtime.migration] Running upgrade mitaka01 -> mitaka02, update metadef os_nova_server
INFO  [alembic.runtime.migration] Running upgrade mitaka02 -> ocata_expand01, add visibility to images
INFO  [alembic.runtime.migration] Running upgrade ocata_expand01 -> pike_expand01, empty expand for symmetry with pike_contract01
INFO  [alembic.runtime.migration] Running upgrade pike_expand01 -> queens_expand01
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
Upgraded database to: queens_expand01, current revision(s): queens_expand01
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
Database migration is up to date. No migration needed.
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade mitaka02 -> ocata_contract01, remove is_public from images
INFO  [alembic.runtime.migration] Running upgrade ocata_contract01 -> pike_contract01, drop glare artifacts tables
INFO  [alembic.runtime.migration] Running upgrade pike_contract01 -> queens_contract01
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
Upgraded database to: queens_contract01, current revision(s): queens_contract01
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
Database is synced successfully.
[root@controller ~]# mysql -hlocalhost -uglance -popenstack -e "use glance;show tables;"

（6）服务启动并设置开启自启

[root@controller ~]# systemctl enable openstack-glance-api.service openstack-glance-registry.service 
[root@controller ~]# systemctl start openstack-glance-api.service  openstack-glance-registry.service

5.2、验证

（1）执行授权

[root@controller ~]# source admin_openrc

（2）下载实验镜像cirros

[root@controller ~]# wget http://download.cirros-cloud.net/0.3.5/cirros-0.3.5-x86_64-disk.img

（3）创建镜像：

[root@controller ~]# openstack image create "cirros" --file cirros-0.3.5-x86_64-disk.img --disk-format qcow2 --container-format bare  --public
+------------------+------------------------------------------------------+
| Field            | Value                                             |
+------------------+------------------------------------------------------+
| checksum         | ee1eca47dc88f4879d8a229cc70a07c6             |
| container_format | bare                                              |
| created_at       | 2020-03-17T14:16:48Z                             |
| disk_format      | qcow2                                            |
| file             | 2/images/7dfa1f88-6e3a-45aa-90ff-f348e6e399c0/file |
| id               | 7dfa1f88-6e3a-45aa-90ff-f348e6e399c0             |
| min_disk         | 0                                                 |
| min_ram          | 0                                                |
| name             | cirros                                           |
| owner            | db82536ef7124608b3f3931ba4ce9615             |
| protected        | False                                             |
| schema           | /v2/schemas/image                               |
| size             | 13287936                                         |
| status           | active                                             |
| tags             |                                                   |
| updated_at       | 2020-03-17T14:16:48Z                             |
| virtual_size     | None                                               |
| visibility       | public                                               |
+------------------+------------------------------------------------------+
[root@controller ~]# openstack image list
+--------------------------------------+--------+--------+
| ID                                   | Name   | Status |
+--------------------------------------+--------+--------+
| 7dfa1f88-6e3a-45aa-90ff-f348e6e399c0 | cirros | active |
+--------------------------------------+--------+--------+

#查看镜像文件信息
[root@controller ~]# openstack image show cirros

#设置镜像受保护状态（不可删除）
[root@controller ~]# openstack image set --protected  IDNAME
#设置镜像未受保护状态（可删除）
[root@controller ~]# openstack image set --unprotected  IDNAME

至此完成Glance的安装，下一章节简介Nova 组件，以及它的安装过程