一、命令介绍
1.split命令
[root@iZbp187tvtln33l6u05tq6Z test]# split --help
Usage: split [OPTION]... [INPUT [PREFIX]]
Output fixed-size pieces of INPUT to PREFIXaa, PREFIXab, ...; default
size is 1000 lines, and default PREFIX is 'x'. With no INPUT, or when INPUT
is -, read standard input.Mandatory arguments to long options are mandatory for short options too.-a, --suffix-length=N generate suffixes of length N (default 2)--additional-suffix=SUFFIX append an additional SUFFIX to file names-b, --bytes=SIZE put SIZE bytes per output file-C, --line-bytes=SIZE put at most SIZE bytes of lines per output file-d, --numeric-suffixes[=FROM] use numeric suffixes instead of alphabetic;FROM changes the start value (default 0)-e, --elide-empty-files do not generate empty output files with '-n'--filter=COMMAND write to shell COMMAND; file name is $FILE-l, --lines=NUMBER put NUMBER lines per output file-n, --number=CHUNKS generate CHUNKS output files; see explanation below-u, --unbuffered immediately copy input to output with '-n r/...'--verbose print a diagnostic just before eachoutput file is opened--help display this help and exit--version output version information and exitSIZE is an integer and optional unit (example: 10M is 10*1024*1024). Units
are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB, ... (powers of 1000).CHUNKS may be:
N split into N files based on size of input
K/N output Kth of N to stdout
l/N split into N files without splitting lines
l/K/N output Kth of N to stdout without splitting lines
r/N like 'l' but use round robin distribution
r/K/N likewise but only output Kth of N to stdout
2.cat命令
Usage: cat [OPTION]... [FILE]...
Concatenate FILE(s), or standard input, to standard output.-A, --show-all equivalent to -vET-b, --number-nonblank number nonempty output lines, overrides -n-e equivalent to -vE-E, --show-ends display $ at end of each line-n, --number number all output lines-s, --squeeze-blank suppress repeated empty output lines-t equivalent to -vT-T, --show-tabs display TAB characters as ^I-u (ignored)-v, --show-nonprinting use ^ and M- notation, except for LFD and TAB--help display this help and exit--version output version information and exitWith no FILE, or when FILE is -, read standard input.Examples:cat f - g Output f's contents, then standard input, then g's contents.cat Copy standard input to standard output.
二、演示
本次使用容器镜像文件演示，将完整镜像做成tar包，直接切割tar包后再合并，再加载镜像tar包到本地环境，用刚加载的镜像run一个容器，看能否正常工作
1.先找个镜像做成tar包
用nginx-1.16.1:v1镜像
[root@iZbp187tvtln33l6u05tq6Z experiment]# nerdctl image ls
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
centos7-base v1 6f5f338e1361 7 months ago linux/amd64 454.8 MiB 154.3 MiB
centos centos7.9.2009 be65f488b776 7 months ago linux/amd64 214.8 MiB 72.6 MiB
nginx-1.16.1 v1 12be16c071b2 55 minutes ago linux/amd64 469.7 MiB 158.3 MiB
nginx-1.16.1 v2 7b30649ffc67 5 months ago linux/amd64 469.7 MiB 158.3 MiB
nginx-1.16.3 v3 0abe1c1f1e0a 5 months ago linux/amd64 469.7 MiB 158.3 MiB
nginx latest c26ae7472d62 8 months ago linux/amd64 191.9 MiB 67.3 MiB
[root@iZbp187tvtln33l6u05tq6Z experiment]# nerdctl save -o nginx.tar nginx-1.16.1:v1
[root@iZbp187tvtln33l6u05tq6Z experiment]# ll
total 162160
-rw-r--r-- 1 root root 166050816 Oct 23 11:41 nginx.tar
2.删除本地已有的镜像
[root@iZbp187tvtln33l6u05tq6Z experiment]# nerdctl image rm nginx-1.16.1:v1
Untagged: docker.io/library/nginx-1.16.1:v1@sha256:12be16c071b25a5ac57e1dd60863796c1b6919b43c62658587947a2f2a708538
Deleted: sha256:174f5685490326fc0a1c0f5570b8663732189b327007e47ff13d2ca59673db02
Deleted: sha256:89f285956a59b0efb45e706472fe0501393c87d8dce10c369a80aaf02df4c1d4
Deleted: sha256:0af98a3443f019148394530ebb94746ec084a8cc1975f08d518d835c484f032f
Deleted: sha256:b13a4358ea58c3b17a66d8fd1c6934599aed3e8c6a5ee5172710adb44e067247
Deleted: sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef
Deleted: sha256:2c35b74746e200b87098082d66c3f30aad6ba9b8eee631439871cdaa9838a5da
[root@iZbp187tvtln33l6u05tq6Z experiment]# nerdctl image ls
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
centos7-base v1 6f5f338e1361 7 months ago linux/amd64 454.8 MiB 154.3 MiB
centos centos7.9.2009 be65f488b776 7 months ago linux/amd64 214.8 MiB 72.6 MiB
nginx-1.16.1 v2 7b30649ffc67 5 months ago linux/amd64 469.7 MiB 158.3 MiB
nginx-1.16.3 v3 0abe1c1f1e0a 5 months ago linux/amd64 469.7 MiB 158.3 MiB
nginx latest c26ae7472d62 8 months ago linux/amd64 191.9 MiB 67.3 MiB
## 上面看到nginx-1.16.1:v1已经被删除了
3.切割tar包
[root@iZbp187tvtln33l6u05tq6Z experiment]# split -b 50MB nginx.tar ng- --additional-suffix=.tar
[root@iZbp187tvtln33l6u05tq6Z experiment]# ls
ng-aa.tar ng-ab.tar ng-ac.tar ng-ad.tar nginx.tar
命令解析：
-b：每个小文件的大小
ng-：添加文件前缀，这个可以自定义
–additional-suffix：添加文件后缀
[root@iZbp187tvtln33l6u05tq6Z experiment]# ll
total 324332
-rw-r--r-- 1 root root 50000000 Oct 23 11:50 ng-aa.tar
-rw-r--r-- 1 root root 50000000 Oct 23 11:50 ng-ab.tar
-rw-r--r-- 1 root root 50000000 Oct 23 11:50 ng-ac.tar
-rw-r--r-- 1 root root 16050816 Oct 23 11:50 ng-ad.tar
-rw-r--r-- 1 root root 166050816 Oct 23 11:41 nginx.tar
[root@iZbp187tvtln33l6u05tq6Z experiment]# md5sum *
2fea19a7325ff8feffde4a04e122700e ng-aa.tar
e64eaa4230879a6a0525bb91548412f4 ng-ab.tar
eaa0e14e5d4ae31011b94b65fe42aa4d ng-ac.tar
d47545545ee1dbb73f7f1b7eaa62de6a ng-ad.tar
fb4f39eecba84a48b1d008b49f2881d5 nginx.tar
- 切割完后能看到，前三个文件被均匀的分割成50MB，且每个文件MD5码均不相同
- 这个时候根据实际场景，想发送的发送，想下载的下载
- 奈何环境有限，这里我们假设已经发送到另外一台机器，然后再继续接下来的步骤
4.合并文件
[root@iZbp187tvtln33l6u05tq6Z experiment]# mv ng-* ../test/
[root@iZbp187tvtln33l6u05tq6Z experiment]# cd ../test
[root@iZbp187tvtln33l6u05tq6Z test]# ls
ng-aa.tar ng-ab.tar ng-ac.tar ng-ad.tar
[root@iZbp187tvtln33l6u05tq6Z test]# cat ng-ab.tar >>ng-aa.tar
[root@iZbp187tvtln33l6u05tq6Z test]# cat ng-ac.tar >>ng-aa.tar
[root@iZbp187tvtln33l6u05tq6Z test]# cat ng-ad.tar >>ng-aa.tar
[root@iZbp187tvtln33l6u05tq6Z test]# ll
total 275500
-rw-r--r-- 1 root root 166050816 Oct 23 12:02 ng-aa.tar
-rw-r--r-- 1 root root 50000000 Oct 23 11:50 ng-ab.tar
-rw-r--r-- 1 root root 50000000 Oct 23 11:50 ng-ac.tar
-rw-r--r-- 1 root root 16050816 Oct 23 11:50 ng-ad.tar
- 刚开始我以为有其他命令将文件合并，毕竟是tar包，没想到cat直接追加也好使，有点暴力
- 实际上vi也能打开tar，只不过里面是加密过得内容，能用vi打开那就把tar包当做特殊的文本文件来看，这么来看cat直接追加也能说得通
5.比较新tar包和老tar包的MD5
[root@iZbp187tvtln33l6u05tq6Z test]# md5sum ng-aa.tar ../experiment/nginx.tar
fb4f39eecba84a48b1d008b49f2881d5 ng-aa.tar
fb4f39eecba84a48b1d008b49f2881d5 ../experiment/nginx.tar
MD5码一样
6.加载本地镜像
[root@iZbp187tvtln33l6u05tq6Z test]# nerdctl load -i ng-aa.tar
unpacking docker.io/library/nginx-1.16.1:v1 (sha256:12be16c071b25a5ac57e1dd60863796c1b6919b43c62658587947a2f2a708538)...
Loaded image: nginx-1.16.1:v1
[root@iZbp187tvtln33l6u05tq6Z test]# nerdctl image ls
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
centos7-base v1 6f5f338e1361 7 months ago linux/amd64 454.8 MiB 154.3 MiB
centos centos7.9.2009 be65f488b776 7 months ago linux/amd64 214.8 MiB 72.6 MiB
nginx-1.16.1 v1 12be16c071b2 12 seconds ago linux/amd64 469.7 MiB 158.3 MiB
nginx-1.16.1 v2 7b30649ffc67 5 months ago linux/amd64 469.7 MiB 158.3 MiB
nginx-1.16.3 v3 0abe1c1f1e0a 5 months ago linux/amd64 469.7 MiB 158.3 MiB
nginx latest c26ae7472d62 8 months ago linux/amd64 191.9 MiB 67.3 MiB
##能看到这个nginx-1.16.1:v1创建时间是12秒前，说明是刚加载的镜像
7.run一个容器
[root@iZbp187tvtln33l6u05tq6Z test]# nerdctl run -d --name split-test -p 8080:80 nginx-1.16.1:v1
56338b68619bde51d140590c8de3c80f48b74dd6a800fe8f7461dc8d4774167d
[root@iZbp187tvtln33l6u05tq6Z test]# nerdctl ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2ba700e7f5a3 docker.io/library/nginx-1.16.3:v3 "/bin/sh -c echo `if…" 5 months ago Created 0.0.0.0:80->80/tcp nginx
56338b68619b docker.io/library/nginx-1.16.1:v1 "/bin/sh -c echo `if…" 6 seconds ago Up 0.0.0.0:8080->80/tcp split-test
## split-test容器已经启动了
curl一下看看
[root@iZbp187tvtln33l6u05tq6Z experiment]# curl 127.0.0.1:8080
10.4.0.11
[root@iZbp187tvtln33l6u05tq6Z test]# nerdctl inspect 56338b68619b | jq -r .[0].NetworkSettings.Networks[].IPAddress
10.4.0.11
##IP一样，测试成功
