OpenNebula 镜像管理分析

Bertha 。 2022-03-16 15:10 224阅读 0赞

从OpenNebula 3.8开始增加了镜像管理的功能，主要体现在增加了CLI - oneimage及其sunstone对应的UI。

1. 镜像类型

opennebula有三种类型的镜像，可以通过oneimage chtype改变镜像的类型。

*  OS：此种镜像包含一个完整的os，每一个virtual template必须包含一个OS型的镜像作为root disk
 *  CDROM：此种镜像包含只读的数据
 *  DATABLOCK：此种镜像作为数据的存储，能够被不同的vm访问和修改

2. 镜像的生命周期

<table style="word-wrap:break-word"> 
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        <th style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> State</th> 
        <th style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> Meaning</th> 
       </tr> 
       <tr style="word-wrap:break-word"> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> lock</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> LOCKED</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> The image file is being copied or created in the Datastore.</td> 
       </tr> 
       <tr style="word-wrap:break-word"> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> rdy</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> READY</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> Image ready to be used.</td> 
       </tr> 
       <tr style="word-wrap:break-word"> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> used</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> USED</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> Non-persistent Image used by at least one VM. It can still be used by other VMs.</td> 
       </tr> 
       <tr style="word-wrap:break-word"> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> used</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> USED_PERS</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> Persistent Image is use by a VM. It cannot be used by new VMs.</td> 
       </tr> 
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        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> disa</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> DISABLED</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> Image disabled by the owner, it cannot be used by new VMs.</td> 
       </tr> 
       <tr style="word-wrap:break-word"> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> err</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> ERROR</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> Error state, a FS operation failed. See the Image information with&nbsp;<span style="word-wrap:break-word">oneimage show</span>&nbsp;for an error message.</td> 
       </tr> 
       <tr style="word-wrap:break-word"> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> dele</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> DELETE</td> 
        <td style="word-wrap:break-word; margin-top:0px; margin-right:0px; margin-bottom:0px; margin-left:0px; padding-top:0px; padding-right:0px; padding-bottom:0px; padding-left:0px"> The image is being deleted from the Datastore.</td> 
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    </div> </td> 
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镜像生命周期的状态转换图

![Image 1][]

![20940095_1365513098x7Sh.png][]

3. 镜像创建

首先，编写镜像创建的配置文件，如下所示：

该文件的意思为：

a. 此镜像的名称为"Ubuntu"

b. 做好的镜像文件的路径为/home/cloud/images/ubuntu-desktop/disk.0,注意oneimage的功能是将做好的image文件导入opennebula的镜像管理模块中，并不是从一个iso文件来创建一个镜像文件，所以，需要事先通过virt-manager或virsh命令行来制作image文件

c. 指定镜像的类型为OS，即包含一个OS

d. 此镜像的简单描述

写好配置文件后，通过oneimage命令将此image添加到image repository中，具体命令如下：

1.  oneimage create ubuntu\_image.one \-d 100 // \-d 选项指定此镜像属于哪个datastore

4. 镜像克隆

此功能为将已经存在的image克隆成一个新的，主要用于在修改一个镜像前的备份以及从公共镜像克隆一个私有的镜像，具体的命令为：

1.  oneimage clone oldimage\_name newimage\_name

5. 发布镜像

这里的发布，指的是将某个用户的镜像与其他用户或全部用户共享，通过oneimage chmod image\_permission来实现， 类似于文件的权限控制。

上传镜像的操作是通过downloader.sh脚本来实现的，其功能是将镜像上传到指定的datastore的目录下，位置为： $INSTALL\_PATH/var/datastores/100/

1.  \#downloader.sh分析  
    
2.    
    
3.  \# Execute a command (first parameter) and use the first kb of stdout  
    
4.  \# to determine the file type  
    
5.  \# 获取上传image文件的类型，具体执行操作为：cat path/image | head \-n 1024 | file \-b \-\-mime\-type \-  
    
6.  function get\_type  
    
7.  \{   
    
8.  if \[ "$NO\_DECOMPRESS" = "yes" \]; then  
    
9.  echo "application/octet-stream"  
    
10. else  
    
11. command=$1  
    
12.   
    
13. ( $command | head \-n 1024 | file \-b \-\-mime\-type \- ) 2>/dev/null  
    
14. fi  
    
15. \}  
    
16.   
    
17. \# Gets the command needed to decompress an stream.  
    
18. function get\_decompressor \#get\_type函数的返回值作为参数  
    
19. \{   
    
20. type=$1  
    
21.   
    
22. case "$type" in  
    
23. "application/x-gzip")  
    
24. echo "gunzip -c -"  
    
25. ;;  
    
26. "application/x-bzip2")  
    
27. echo "bunzip2 -c -"  
    
28. ;;  
    
29. \*)  
    
30. echo "cat"  
    
31. ;;  
    
32. esac  
    
33. \}  
    
34.   
    
35. \# Function called to decompress a stream. The first parameter is the command  
    
36. \# used to decompress the stream. Second parameter is the output file or  
    
37. \# \- for stdout.  
    
38. function decompress  
    
39. \{   
    
40. command="$1"  
    
41. to="$2"  
    
42.   
    
43. if \[ "$to" = "-" \]; then  
    
44. $command  
    
45. else  
    
46. $command > "$to"  
    
47. fi  
    
48. \}  
    
49.   
    
50. \# Function called to hash a stream. First parameter is the algorithm name.  
    
51. function hasher  
    
52. \{   
    
53. if \[ \-n "$1" \]; then  
    
54. openssl dgst \-$1 | awk '\{print $NF\}' > $HASH\_FILE  
    
55. else  
    
56. \# Needs something consuming stdin or the pipe will break  
    
57. cat >/dev/null  
    
58. fi  
    
59. \}  
    
60.   
    
61. \# Unarchives a tar or a zip a file to a directpry with the same name.  
    
62. function unarchive \#\#对压缩的镜像进行解压  
    
63. \{   
    
64. TO="$1"  
    
65.   
    
66. file\_type=$(get\_type "cat $TO")  
    
67.   
    
68. tmp="$TO"  
    
69.   
    
70. \# Add full path if it is relative  
    
71. if \[ $\{ tmp:0:1\} != "/" \]; then  
    
72. tmp="$PWD/$tmp"  
    
73. fi  
    
74.   
    
75. IN="$tmp.tmp"  
    
76. OUT="$tmp"  
    
77.   
    
78. case "$file\_type" in  
    
79. "application/x-tar")  
    
80. command="tar -xf $IN -C $OUT"  
    
81. ;;  
    
82. "application/zip")  
    
83. command="unzip -d $OUT $IN"  
    
84. ;;  
    
85. \*)  
    
86. command=""  
    
87. ;;  
    
88. esac  
    
89.   
    
90. if \[ \-n "$command" \]; then  
    
91. mv "$OUT" "$IN"  
    
92. mkdir "$OUT"  
    
93.   
    
94. $command  
    
95.   
    
96. if \[ "$?" != "0" \]; then  
    
97. echo "Error uncompressing archive" >&2  
    
98. exit \-1  
    
99. fi  
    
100.   
    
101. rm "$IN"  
    
102. fi  
    
103. \}  
    
104.   
    
105. TEMP=\`getopt \-o m:s:l:n \-l md5:,sha1:,limit:,nodecomp \-\- "$@"\`  
    
106.   
    
107. if \[ $? != 0 \] ; then  
    
108. echo "Arguments error"  
    
109. exit \-1  
    
110. fi  
    
111.   
    
112. eval set \-\- "$TEMP"  
    
113.   
    
114. while true; do \#\#\#处理downloader.sh脚本的输入参数  
    
115. case "$1" in  
    
116. \-m|\-\-md5)  
    
117. HASH\_TYPE=md5  
    
118. HASH=$2  
    
119. shift 2  
    
120. ;;  
    
121. \-s|\-\-sha1)  
    
122. HASH\_TYPE=sha1  
    
123. HASH=$2  
    
124. shift 2  
    
125. ;;  
    
126. \-n|\-\-nodecomp)  
    
127. export NO\_DECOMPRESS="yes"  
    
128. shift  
    
129. ;;  
    
130. \-l|\-\-limit)  
    
131. export LIMIT\_RATE="$2"  
    
132. shift 2  
    
133. ;;  
    
134. \-\-)  
    
135. shift  
    
136. break  
    
137. ;;  
    
138. \*)  
    
139. shift  
    
140. ;;  
    
141. esac  
    
142. done  
    
143.   
    
144. FROM="$1"  
    
145. TO="$2"  
    
146.   
    
147. \# File used by the hasher function to store the resulting hash  
    
148. export HASH\_FILE="/tmp/downloader.hash.$$"  
    
149.   
    
150. case "$FROM" in   
    
151. http://\*|https://\*)  
    
152. \# \-k so it does not check the certificate  
    
153. \# \-L to follow redirects  
    
154. \# \-sS to hide output except on failure  
    
155. \# \-\-limit\_rate to limit the bw  
    
156. curl\_args="-sS -k -L $FROM"  
    
157.   
    
158. if \[ \-n "$LIMIT\_RATE" \]; then  
    
159. curl\_args="--limit-rate $LIMIT\_RATE $curl\_args"  
    
160. fi  
    
161.   
    
162. command="curl $curl\_args"  
    
163. ;;  
    
164. \*)  
    
165. command="cat $FROM"  
    
166. ;;  
    
167. esac  
    
168.   
    
169.   
    
170.   
    
171. file\_type=$(get\_type "$command")  
    
172. decompressor=$(get\_decompressor "$file\_type")  
    
173.   
    
174. echo $file\_type  
    
175. echo $decompressor  
    
176.   
    
177. $command | tee >( decompress "$decompressor" "$TO" ) \\  
    
178. >( hasher $HASH\_TYPE ) >/dev/null  
    
179.   
    
180. if \[ "$?" != "0" \]; then  
    
181. echo "Error copying" >&2  
    
182. exit \-1  
    
183. fi  
    
184.   
    
185. if \[ \-n "$HASH\_TYPE" \]; then  
    
186. HASH\_RESULT=$( cat $HASH\_FILE)  
    
187. rm $HASH\_FILE  
    
188. if \[ "$HASH\_RESULT" != "$HASH" \]; then  
    
189. echo "Hash does not match" >&2  
    
190. exit \-1  
    
191. fi  
    
192. fi  
    
193.   
    
194. \# Unarchive only if the destination is filesystem  
    
195. if \[ "$TO" != "-" \]; then  
    
196. unarchive "$TO"  
    
197. fi

[Image 1]: 
[20940095_1365513098x7Sh.png]: http://blog.chinaunix.net/attachment/201304/9/20940095_1365513098x7Sh.png