Background of the project
In the following example, the two containers comprising Pod: tomcat and busybox, provided Volume "app-logs" in the level Pod for tomcat to write to the log file, the log file is read busybox.
# 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: {}
Volume named app-logs provided herein, type emptyDir (may also be provided for other types), mounted to tomcat / usr / local / tomcat / logs directory within the container, while the mount / logs directory within the container logreader . tomcat container will be writing files to / usr / log / tomcat / logs directory after startup, logreader container which can read the files.
You can view the contents of logreader container output by kubectl logs command:
# 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] ......
Login tomcat container to view:
# 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