如何在dockerized Topbeat中监视主机的文件系统

Question

我想用Elasticsearch Topbeat监控我的主机。但是在Docker容器中运行Topbeat似乎容器看不到主机的FS，而只看到使用--volume run选项挂载的容器。 示例：

root$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       6.9G  2.0G  4.7G  30% /

root$ docker run --name Topbeat --net host --pid host --dns=127.0.0.1 --volume /var/log:/var/log frg-topbeat:latest

root$ docker exec -it Topbeat df -h
Filesystem      Size  Used Avail Use% Mounted on
none            6.9G  2.0G  4.7G  30% /
tmpfs           501M     0  501M   0% /dev
tmpfs           501M     0  501M   0% /sys/fs/cgroup
/dev/vda1       6.9G  2.0G  4.7G  30% /var/log       <-- I wanted to see the / mount point and not only /var/log
shm              64M     0   64M   0% /dev/shm

更新1： Topbeat监控的所有FS都来自'mount'命令：

root$ docker exec -it Topbeat /bin/bash 
root@tst-rpx-master-0:/# mount
...
/dev/vda1 on /var/log type ext3 (rw,relatime,errors=remount-ro,data=ordered)
/dev/vda1 on /etc/resolv.conf type ext3 (rw,relatime,errors=remount-ro,data=ordered)
/dev/vda1 on /etc/hostname type ext3 (rw,relatime,errors=remount-ro,data=ordered)
/dev/vda1 on /etc/hosts type ext3 (rw,relatime,errors=remount-ro,data=ordered)
...