Pod容器共享 Volume

項目背景

在下面示例中，Pod內包含兩個容器：tomcat 和 busybox ,在 Pod 級別設置 Volume “app-logs”，用于 tomcat 向其中寫入日志文件，busybox 讀日志文件。

#?cat?pod-volume-applogs.yaml?
apiVersion:?v1
kind:?Pod
metadata:
??name:?volume-pod
spec:
??containers:
??-?name:?tomcat
???image:?tomcat
???ports:
???-?containerPort:?8080
???volumeMounts:
???-?name:?app-logs
?????mountPath:?/usr/local/tomcat/logs
??-?name:?busybox
???image:?busybox
???command:?["sh","-c","tail?-f?/logs/catalina*.log"]
???volumeMounts:
???-?name:?app-logs
?????mountPath:?/logs
??volumes:
??-?name:?app-logs
???emptyDir:?{}

這里設置的 Volume 名為 app-logs，類型為 emptyDir(也可以設置為其他類型)，掛載到 tomcat 容器內的 /usr/local/tomcat/logs 目錄，同時掛載到 logreader 容器內的 /logs 目錄。tomcat 容器會在啟動后會向 /usr/log/tomcat/logs 目錄中寫文件，logreader 容器就可以讀取其中的文件了。

可以通過 kubectl logs 命令查看 logreader 容器的輸出內容：

#?find?/?-name?app-logs
[root@master?other]#?kubectl?logs?volume-pod?-c?busybox
26-Jul-2019?18:06:22.126?INFO?[main]?org.apache.catalina.startup.VersionLoggerListener.log?Command?line?argument:?-Djava.protocol.handler.pkgs=org.apache.catalina.w
ebresources26-Jul-2019?18:06:22.126?INFO?[main]?org.apache.catalina.startup.VersionLoggerListener.log?Command?line?argument:?-Dorg.apache.catalina.security.SecurityListener.UM
ASK=002726-Jul-2019?18:06:22.144?INFO?[main]?org.apache.catalina.startup.VersionLoggerListener.log?Command?line?argument:?-Dignore.endorsed.dirs=
26-Jul-2019?18:06:22.144?INFO?[main]?org.apache.catalina.startup.VersionLoggerListener.log?Command?line?argument:?-Dcatalina.base=/usr/local/tomcat
26-Jul-2019?18:06:22.144?INFO?[main]?
......

登錄 tomcat 容器進行查看：

#?kubectl?exec?-it?volume-pod?-c?tomcat?--?ls?/usr/local/tomcat/logs
catalina.2019-07-26.log?????localhost_access_log.2019-07-26.txt
host-manager.2019-07-26.log??manager.2019-07-26.log
localhost.2019-07-26.log

#?kubectl?exec?-it?volume-pod?-c?tomcat?--?tail?/usr/local/tomcat/logs/catalina.2019-07-26.log
26-Jul-2019?18:06:29.935?INFO?[localhost-startStop-1]?org.apache.catalina.startup.HostConfig.deployDirectory?Deployment?of?web?application?directory?[/usr/local/tom
cat/webapps/docs]?has?finished?in?[388]?ms26-Jul-2019?18:06:29.936?INFO?[localhost-startStop-1]?org.apache.catalina.startup.HostConfig.deployDirectory?Deploying?web?application?directory?[/usr/local/tomcat/
webapps/examples]26-Jul-2019?18:06:32.777?INFO?[localhost-startStop-1]?org.apache.catalina.startup.HostConfig.deployDirectory?Deployment?of?web?application?directory?[/usr/local/tomcat