[continue 912] strip rootfs prefix for run in docker (#1058)

* strip rootfs prefix for run in docker
* Use `/` as default value of path.rootfs, and parse mounts from `/proc/1/mounts`.
* No need to mount `/proc` and `/sys` because we share host's PID
namespace, which allows processes within the container to see all of the
processes on the system.

Closes: #66

Signed-off-by: Ivan Mikheykin <ivan.mikheykin@flant.com>
Signed-off-by: Yecheng Fu <cofyc.jackson@gmail.com>
This commit is contained in:
Yecheng Fu 2018-10-04 20:11:21 +08:00 committed by Ben Kochie
parent 2269df255c
commit 0f9842f20a
4 changed files with 48 additions and 6 deletions

View file

@ -144,12 +144,17 @@ The `node_exporter` is designed to monitor the host system. It's not recommended
to deploy it as a Docker container because it requires access to the host system.
Be aware that any non-root mount points you want to monitor will need to be bind-mounted
into the container.
If you start container for host monitoring, specify `path.rootfs` argument.
This argument must match path in bind-mount of host root. The node\_exporter will use
`path.rootfs` as prefix to access host filesystem.
```bash
docker run -d \
--net="host" \
--pid="host" \
quay.io/prometheus/node-exporter
-v "/:/host:ro,rslave" \
quay.io/prometheus/node-exporter \
--path.rootfs /host
```
On some systems, the `timex` collector requires an additional Docker flag,

View file

@ -70,7 +70,7 @@ func (c *filesystemCollector) GetStats() ([]filesystemStats, error) {
go stuckMountWatcher(labels.mountPoint, success)
buf := new(syscall.Statfs_t)
err = syscall.Statfs(labels.mountPoint, buf)
err = syscall.Statfs(rootfsFilePath(labels.mountPoint), buf)
stuckMountsMtx.Lock()
close(success)
@ -86,7 +86,7 @@ func (c *filesystemCollector) GetStats() ([]filesystemStats, error) {
labels: labels,
deviceError: 1,
})
log.Debugf("Error on statfs() system call for %q: %s", labels.mountPoint, err)
log.Debugf("Error on statfs() system call for %q: %s", rootfsFilePath(labels.mountPoint), err)
continue
}
@ -133,7 +133,7 @@ func stuckMountWatcher(mountPoint string, success chan struct{}) {
}
func mountPointDetails() ([]filesystemLabels, error) {
file, err := os.Open(procFilePath("mounts"))
file, err := os.Open(procFilePath("1/mounts"))
if err != nil {
return nil, err
}

View file

@ -0,0 +1,32 @@
rootfs / rootfs rw 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,relatime,size=10240k,nr_inodes=1008585,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,nosuid,relatime,size=1617716k,mode=755 0 0
/dev/dm-2 / ext4 rw,relatime,errors=remount-ro,data=ordered 0 0
securityfs /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
tmpfs /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
tmpfs /sys/fs/cgroup tmpfs ro,nosuid,nodev,noexec,mode=755 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd 0 0
pstore /sys/fs/pstore pstore rw,nosuid,nodev,noexec,relatime 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset 0 0
cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0
cgroup /sys/fs/cgroup/net_cls,net_prio cgroup rw,nosuid,nodev,noexec,relatime,net_cls,net_prio 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0
cgroup /sys/fs/cgroup/perf_event cgroup rw,nosuid,nodev,noexec,relatime,perf_event 0 0
systemd-1 /proc/sys/fs/binfmt_misc autofs rw,relatime,fd=22,pgrp=1,timeout=300,minproto=5,maxproto=5,direct 0 0
mqueue /dev/mqueue mqueue rw,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
hugetlbfs /dev/hugepages hugetlbfs rw,relatime 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
/dev/sda3 /boot ext2 rw,relatime 0 0
rpc_pipefs /run/rpc_pipefs rpc_pipefs rw,relatime 0 0
binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc rw,relatime 0 0
tmpfs /run/user/1000 tmpfs rw,nosuid,nodev,relatime,size=808860k,mode=700,uid=1000,gid=1000 0 0
gvfsd-fuse /run/user/1000/gvfs fuse.gvfsd-fuse rw,nosuid,nodev,relatime,user_id=1000,group_id=1000 0 0
/dev/sda /var/lib/kubelet/plugins/kubernetes.io/vsphere-volume/mounts/[vsanDatastore]\040bafb9e5a-8856-7e6c-699c-801844e77a4a/kubernetes-dynamic-pvc-3eba5bba-48a3-11e8-89ab-005056b92113.vmdk ext4 rw,relatime,data=ordered 0 0
/dev/sda /var/lib/kubelet/plugins/kubernetes.io/vsphere-volume/mounts/[vsanDatastore]\011bafb9e5a-8856-7e6c-699c-801844e77a4a/kubernetes-dynamic-pvc-3eba5bba-48a3-11e8-89ab-005056b92113.vmdk ext4 rw,relatime,data=ordered 0 0

View file

@ -22,8 +22,9 @@ import (
var (
// The path of the proc filesystem.
procPath = kingpin.Flag("path.procfs", "procfs mountpoint.").Default(procfs.DefaultMountPoint).String()
sysPath = kingpin.Flag("path.sysfs", "sysfs mountpoint.").Default("/sys").String()
procPath = kingpin.Flag("path.procfs", "procfs mountpoint.").Default(procfs.DefaultMountPoint).String()
sysPath = kingpin.Flag("path.sysfs", "sysfs mountpoint.").Default("/sys").String()
rootfsPath = kingpin.Flag("path.rootfs", "rootfs mountpoint.").Default("/").String()
)
func procFilePath(name string) string {
@ -33,3 +34,7 @@ func procFilePath(name string) string {
func sysFilePath(name string) string {
return path.Join(*sysPath, name)
}
func rootfsFilePath(name string) string {
return path.Join(*rootfsPath, name)
}