From 522c5347500b021bd66001fc5da86660a419332f Mon Sep 17 00:00:00 2001 From: Yecheng Fu Date: Thu, 4 Oct 2018 20:11:21 +0800 Subject: [PATCH] [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 Signed-off-by: Yecheng Fu --- README.md | 7 ++++++- collector/filesystem_linux.go | 6 +++--- collector/fixtures/proc/1/mounts | 32 ++++++++++++++++++++++++++++++++ collector/paths.go | 9 +++++++-- 4 files changed, 48 insertions(+), 6 deletions(-) create mode 100644 collector/fixtures/proc/1/mounts diff --git a/README.md b/README.md index a0eafa65c3..760712f38c 100644 --- a/README.md +++ b/README.md @@ -171,12 +171,17 @@ 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, diff --git a/collector/filesystem_linux.go b/collector/filesystem_linux.go index 5e2e37b5ce..74701d4583 100644 --- a/collector/filesystem_linux.go +++ b/collector/filesystem_linux.go @@ -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 } diff --git a/collector/fixtures/proc/1/mounts b/collector/fixtures/proc/1/mounts new file mode 100644 index 0000000000..7452d495a6 --- /dev/null +++ b/collector/fixtures/proc/1/mounts @@ -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 diff --git a/collector/paths.go b/collector/paths.go index f8e6e6e535..a3a61ad11e 100644 --- a/collector/paths.go +++ b/collector/paths.go @@ -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) +}