Glance（OpenStack Image Service）是一个提供发现、注册和下载镜像的服务。Glance 提供了虚拟机镜像的集中存储，通过 Glance 的 RESTful API，可以查询镜像元数据和下载镜像。虚拟机的镜像可以很方便的存储在各种地方，从简单的文件系统到对象存储系统(比如 OpenStack Swift)。
Glance支持多种后端存储，比如nfs和ceph作为Glance的后端存储用于存储镜像。建议使用ceph作为后端存储服务，这也是官方建议。
Glance 具体功能如下：
- 提供 RESTful API 让用户能够查询和获取镜像的元数据和镜像本身；
- 支持多种方式存储镜像，包括普通的文件系统、Swift、Ceph 等；
- 对实例执行快照创建新的镜像。
- 在 Newton 之前的版本中，Glance 支持两种 RESTful API V1和V2，两者区别为：
- V1只提供了基本的镜像和用户操作功能：镜像创建、删除、下载、列表、详细信息查询、更新，以及镜像租户成员的创建、删除和列表。
- V2除了支持V1的所有功能外，主要是增加了如下功能：
- 镜像 location 的添加、删除和修改等操作；
- metadata namespace 操作；
- 镜像 tag 操作。
- V1和V2对镜像后端存储的支持是相同的。
安装glance（控制节点，node1）
---------------------------------------------#初始化数据库，glance连接mysql用户密码glance/glance
mysql -uroot -pmysql << EOF
CREATE DATABASE glance;
GRANT ALL PRIVILEGES ON glance.* TO 'glance'@'localhost' \
IDENTIFIED BY 'glance';
GRANT ALL PRIVILEGES ON glance.* TO 'glance'@'%' \
IDENTIFIED BY 'glance';
EOF
---------------------------------------------#创建用户，node1执行
[root@node1 ~]# . admin-openrc
[root@node1 ~]# openstack user create --domain default --password-prompt glance # 输入glance密码glance
User Password:
Repeat User Password:
+---------------------+----------------------------------+
| Field | Value |
+---------------------+----------------------------------+
| domain_id | default |
| enabled | True |
| id | 74b8f80f91084f0a8b17bb04a3fd47b1 |
| name | glance |
| options | {} |
| password_expires_at | None |
+---------------------+----------------------------------+
[root@node1 ~]# openstack role add --project service --user glance admin
[root@node1 ~]# openstack service create --name glance --description "OpenStack Image" image
+-------------+----------------------------------+
| Field | Value |
+-------------+----------------------------------+
| description | OpenStack Image |
| enabled | True |
| id | d421acdbcaaa4a5f92d87c20c4ebfec2 |
| name | glance |
| type | image |
+-------------+----------------------------------+
[root@node1 ~]# openstack endpoint create --region RegionOne image public http://node1:9292
+--------------+----------------------------------+
| Field | Value |
+--------------+----------------------------------+
| enabled | True |
| id | 38aa9583a2274dc6b6cce8289e5a518c |
| interface | public |
| region | RegionOne |
| region_id | RegionOne |
| service_id | d421acdbcaaa4a5f92d87c20c4ebfec2 |
| service_name | glance |
| service_type | image |
| url | http://node1:9292 |
+--------------+----------------------------------+
[root@node1 ~]# openstack endpoint create --region RegionOne image internal http://node1:9292
+--------------+----------------------------------+
| Field | Value |
+--------------+----------------------------------+
| enabled | True |
| id | 85ec01a12a424c328a554e1c925b5ac4 |
| interface | internal |
| region | RegionOne |
| region_id | RegionOne |
| service_id | d421acdbcaaa4a5f92d87c20c4ebfec2 |
| service_name | glance |
| service_type | image |
| url | http://node1:9292 |
+--------------+----------------------------------+
[root@node1 ~]# openstack endpoint create --region RegionOne image admin http://node1:9292
+--------------+----------------------------------+
| Field | Value |
+--------------+----------------------------------+
| enabled | True |
| id | d1391c0234f74f3cbdb8df8f94ffca17 |
| interface | admin |
| region | RegionOne |
| region_id | RegionOne |
| service_id | d421acdbcaaa4a5f92d87c20c4ebfec2 |
| service_name | glance |
| service_type | image |
| url | http://node1:9292 |
+--------------+----------------------------------+
---------------------------------------------#安装配置组件
yum --enablerepo powertools -y install openstack-glance
crudini --set /etc/glance/glance-api.conf database connection mysql+pymysql://glance:glance@node1/glance
crudini --set /etc/glance/glance-api.conf keystone_authtoken www_authenticate_uri http://node1:5000
crudini --set /etc/glance/glance-api.conf keystone_authtoken auth_url http://node1:5000
crudini --set /etc/glance/glance-api.conf keystone_authtoken memcached_servers node1:11211
crudini --set /etc/glance/glance-api.conf keystone_authtoken auth_type password
crudini --set /etc/glance/glance-api.conf keystone_authtoken project_domain_name Default
crudini --set /etc/glance/glance-api.conf keystone_authtoken user_domain_name Default
crudini --set /etc/glance/glance-api.conf keystone_authtoken project_name service
crudini --set /etc/glance/glance-api.conf keystone_authtoken username glance
crudini --set /etc/glance/glance-api.conf keystone_authtoken password glance
crudini --set /etc/glance/glance-api.conf paste_deploy flavor keystone
crudini --set /etc/glance/glance-api.conf glance_store stores file,http
crudini --set /etc/glance/glance-api.conf glance_store default_store file
crudini --set /etc/glance/glance-api.conf glance_store filesystem_store_datadir /var/lib/glance/images/ # 镜像存储目录
---------------------------------------------#初始化数据
/bin/sh -c "glance-manage db_sync" glance
---------------------------------------------#启动服务
chown glance.glance -R /var/log/glance/ # 设置目录及目录下的文件的权限，防止权限错误导致服务无法启动
systemctl enable openstack-glance-api && systemctl start openstack-glance-api
---------------------------------------------#验证，下载并执行上传镜像，node1执行
. admin-openrc
wget http://download.cirros-cloud.net/0.4.0/cirros-0.4.0-x86_64-disk.img
[root@node1 ~]# glance image-create --name "cirros" --file cirros-0.4.0-x86_64-disk.img --disk-format qcow2 --container-format bare --visibility=public
+------------------+----------------------------------------------------------------------------------+
| Property | Value |
+------------------+----------------------------------------------------------------------------------+
| checksum | 443b7623e27ecf03dc9e01ee93f67afe |
| container_format | bare |
| created_at | 2022-03-01T06:47:15Z |
| disk_format | qcow2 |
| id | 377a35ff-8674-4154-b7c9-707255c7474c |
| min_disk | 0 |
| min_ram | 0 |
| name | cirros |
| os_hash_algo | sha512 |
| os_hash_value | 6513f21e44aa3da349f248188a44bc304a3653a04122d8fb4535423c8e1d14cd6a153f735bb0982e |
| | 2161b5b5186106570c17a9e58b64dd39390617cd5a350f78 |
| os_hidden | False |
| owner | c827c773e36d4149a93196b371cebfd9 |
| protected | False |
| size | 12716032 |
| status | active |
| tags | [] |
| updated_at | 2022-03-01T06:47:16Z |
| virtual_size | 46137344 |
| visibility | public |
+------------------+----------------------------------------------------------------------------------+
[root@node1 ~]# glance image-list
+--------------------------------------+--------+
| ID | Name |
+--------------------------------------+--------+
| 377a35ff-8674-4154-b7c9-707255c7474c | cirros |
+--------------------------------------+--------+
# 在上面设置的镜像存储目录/var/lib/glance中可以看到刚刚上传的镜像
[root@node1 ~]# ls -lh /var/lib/glance/images/ -lh
total 13M
-rw-r-----. 1 glance glance 13M Mar 1 14:47 377a35ff-8674-4154-b7c9-707255c7474c
[root@node1 ~]# md5sum cirros-0.4.0-x86_64-disk.img /var/lib/glance/images/377a35ff-8674-4154-b7c9-707255c7474c
443b7623e27ecf03dc9e01ee93f67afe cirros-0.4.0-x86_64-disk.img
443b7623e27ecf03dc9e01ee93f67afe /var/lib/glance/images/377a35ff-8674-4154-b7c9-707255c7474c