Kubernates之从pod中拷贝文件到宿主机

想从k8s的pod中拷贝文件到宿主机，kubectl 的cp命令，但是网上搜索了下，感觉有点乱，自己记录下。

hadoop这个namespace下，有个hadoop-hadoop-yarn-rm-0的pod，它的work_dir是/usr/local/hadoop，在这个目录下有个application_1564318400358_0562_1文件，现在的目的是将此文件拷贝到宿主机上，命令如下List-1所示。由于我们的work_dir是/usr/local/hadoop，所以不需要写完全路径/usr/local/hadoop/application_1564318400358_0562_1，写完全路径反而会报错

List-1

kubectl cp -n hadoop hadoop-hadoop-yarn-rm-0:application_1564318400358_0562_1 ./

如下List-2中报错

List-2

[~]$ kubectl cp -n hadoop hadoop-hadoop-yarn-rm-0:/usr/local/hadoop/application_1564318400358_0562_1 ./
tar: Removing leading `/' from member names
[~]$ kubectl cp -n hadoop hadoop-hadoop-yarn-rm-0:usr/local/hadoop/application_1564318400358_0562_1 ./
error: usr/local/hadoop/application_1564318400358_0562_1 no such file or directory

实例操作:

[root@pressure-pretest-master03 ~]# kubectl cp -n xitu-pressure h5-web-pressure-8498f76b59-mnm66:/var/log/nginx/access.log ./
tar: removing leading '/' from member names
[root@pressure-pretest-master03 ~]# ls

access.log             

[root@pressure-pretest-master03 ~]# tar -czvf access.log.tar.gz access.log
access.log
[root@pressure-pretest-master03 ~]# ls

access.log
access.log.tar.gz

　　

部分 kubectl 的版本原因使用上述 kubctl cp 会报错

emambp:tian ema$ kubectl cp learn-deployments/lrn145033-learn-tom7956c-g9k8q:bb-email-log.txt  /Users/ema/work/bb_cicd/starter/kubernetes/tian/
Defaulting container name to learn.
error: open /Users/ema/work/bb_cicd/starter/kubernetes/tian: is a directory

目标参数必须为文件 不能是一个目录

解决，

emambp:tian ema$ kubectl cp learn-deployments/lrn145033-learn-tom7956c-g9k8q:bb-email-log.txt  /Users/ema/work/bb_cicd/starter/kubernetes/tian/bb-email-log.txt

总结：

源参数 不能是以“/” 开头的，所以可以把需要copy的文件先拷贝到pod的工作目录下

目标参数必须为文件  不能是目录

实例操作:

 kubectl version
Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.3", GitCommit:"2d3c76f9091b6bec110a5e63777c332469e0cba2", GitTreeState:"clean", BuildDate:"2019-08-19T11:13:54Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"12+", GitVersion:"v1.12.6-aliyun.1", GitCommit:"8cb561c", GitTreeState:"", BuildDate:"2019-05-23T11:28:17Z", GoVersion:"go1.10.8", Compiler:"gc", Platform:"linux/amd64"}

kubectl cp -n weifeng-test mall-finance-job-provider-69ff7fb8cf-k8p4g:aaa.bin ./aaa.bin

ll
total 186624
-rw-r--r-- 1 root root  191066106 Oct 23 16:56 aaa.bin