node-exporter的工作原理太简单了，简单到市面上无法找到一本知名的书籍来讲解node-exporter的工作原理，但这并不意味着node-exporter不重要，相反基本上有prometheus的地方都会存在node-exporter

通过提供 `--collector.<name>` 标志可以启用收集器。默认启用的收集器可以通过提供 `--no-collector.<name>` 标志来禁用。如需仅启用部分特定收集器，请使用 `--collector.disable-defaults --collector.<name> ...` 。

如果嫌指标太多，可以通过 `./node_exporter -h` 查看支持的flags参数

A few collectors can be configured to include or exclude certain patterns using dedicated flags. The exclude flags are used to indicate "all except", while the include flags are used to say "none except". Note that these flags are mutually exclusive on collectors that support both.

```txt

| Collector | Scope | Include Flag | Exclude Flag |

| ---------- | ------------ | ------------------------------------------- | ------------------------------------------- |

| arp | device | --collector.arp.device-include | --collector.arp.device-exclude |

| cpu | bugs | --collector.cpu.info.bugs-include | N/A |

| cpu | flags | --collector.cpu.info.flags-include | N/A |

| diskstats | device | --collector.diskstats.device-include | --collector.diskstats.device-exclude |

| ethtool | device | --collector.ethtool.device-include | --collector.ethtool.device-exclude |

| ethtool | metrics | --collector.ethtool.metrics-include | N/A |

| filesystem | fs-types | --collector.filesystem.fs-types-include | --collector.filesystem.fs-types-exclude |

| filesystem | mount-points | --collector.filesystem.mount-points-include | --collector.filesystem.mount-points-exclude |

| hwmon | chip | --collector.hwmon.chip-include | --collector.hwmon.chip-exclude |

| hwmon | sensor | --collector.hwmon.sensor-include | --collector.hwmon.sensor-exclude |

| interrupts | name | --collector.interrupts.name-include | --collector.interrupts.name-exclude |

| netdev | device | --collector.netdev.device-include | --collector.netdev.device-exclude |

| qdisk | device | --collector.qdisk.device-include | --collector.qdisk.device-exclude |

| slabinfo | slab-names | --collector.slabinfo.slabs-include | --collector.slabinfo.slabs-exclude |

| sysctl | all | --collector.sysctl.include | N/A |

| systemd | unit | --collector.systemd.unit-include | --collector.systemd.unit-exclude |

Name | Description | OS

---------|-------------|----

arp | Exposes ARP statistics from `/proc/net/arp`. | Linux

bcache | Exposes bcache statistics from `/sys/fs/bcache/`. | Linux

bonding | Exposes the number of configured and active slaves of Linux bonding interfaces. | Linux

btrfs | Exposes btrfs statistics | Linux

boottime | Exposes system boot time derived from the `kern.boottime` sysctl. | Darwin, Dragonfly, FreeBSD, NetBSD, OpenBSD, Solaris

conntrack | Shows conntrack statistics (does nothing if no `/proc/sys/net/netfilter/` present). | Linux

cpu | Exposes CPU statistics | Darwin, Dragonfly, FreeBSD, Linux, Solaris, OpenBSD

cpufreq | Exposes CPU frequency statistics | Linux, Solaris

diskstats | Exposes disk I/O statistics. | Darwin, Linux, OpenBSD

dmi | Expose Desktop Management Interface (DMI) info from `/sys/class/dmi/id/` | Linux

edac | Exposes error detection and correction statistics. | Linux

entropy | Exposes available entropy. | Linux

exec | Exposes execution statistics. | Dragonfly, FreeBSD

fibrechannel | Exposes fibre channel information and statistics from `/sys/class/fc_host/`. | Linux

filefd | Exposes file descriptor statistics from `/proc/sys/fs/file-nr`. | Linux

filesystem | Exposes filesystem statistics, such as disk space used. | Darwin, Dragonfly, FreeBSD, Linux, OpenBSD

hwmon | Expose hardware monitoring and sensor data from `/sys/class/hwmon/`. | Linux

infiniband | Exposes network statistics specific to InfiniBand and Intel OmniPath configurations. | Linux

ipvs | Exposes IPVS status from `/proc/net/ip_vs` and stats from `/proc/net/ip_vs_stats`. | Linux

loadavg | Exposes load average. | Darwin, Dragonfly, FreeBSD, Linux, NetBSD, OpenBSD, Solaris

mdadm | Exposes statistics about devices in `/proc/mdstat` (does nothing if no `/proc/mdstat` present). | Linux

meminfo | Exposes memory statistics. | Darwin, Dragonfly, FreeBSD, Linux, OpenBSD

netclass | Exposes network interface info from `/sys/class/net/` | Linux

netdev | Exposes network interface statistics such as bytes transferred. | Darwin, Dragonfly, FreeBSD, Linux, OpenBSD

netisr | Exposes netisr statistics | FreeBSD

netstat | Exposes network statistics from `/proc/net/netstat`. This is the same information as `netstat -s`. | Linux

nfs | Exposes NFS client statistics from `/proc/net/rpc/nfs`. This is the same information as `nfsstat -c`. | Linux

nfsd | Exposes NFS kernel server statistics from `/proc/net/rpc/nfsd`. This is the same information as `nfsstat -s`. | Linux

nvme | Exposes NVMe info from `/sys/class/nvme/` | Linux

os | Expose OS release info from `/etc/os-release` or `/usr/lib/os-release` | _any_

powersupplyclass | Exposes Power Supply statistics from `/sys/class/power_supply` | Linux

pressure | Exposes pressure stall statistics from `/proc/pressure/`. | Linux (kernel 4.20+ and/or [CONFIG\_PSI](https://www.kernel.org/doc/html/latest/accounting/psi.html))

rapl | Exposes various statistics from `/sys/class/powercap`. | Linux

schedstat | Exposes task scheduler statistics from `/proc/schedstat`. | Linux

selinux | Exposes SELinux statistics. | Linux

sockstat | Exposes various statistics from `/proc/net/sockstat`. | Linux

softnet | Exposes statistics from `/proc/net/softnet_stat`. | Linux

stat | Exposes various statistics from `/proc/stat`. This includes boot time, forks and interrupts. | Linux

tapestats | Exposes statistics from `/sys/class/scsi_tape`. | Linux

textfile | Exposes statistics read from local disk. The `--collector.textfile.directory` flag must be set. | _any_

thermal | Exposes thermal statistics like `pmset -g therm`. | Darwin

thermal\_zone | Exposes thermal zone & cooling device statistics from `/sys/class/thermal`. | Linux

time | Exposes the current system time. | _any_

timex | Exposes selected adjtimex(2) system call stats. | Linux

udp_queues | Exposes UDP total lengths of the rx_queue and tx_queue from `/proc/net/udp` and `/proc/net/udp6`. | Linux

uname | Exposes system information as provided by the uname system call. | Darwin, FreeBSD, Linux, OpenBSD

vmstat | Exposes statistics from `/proc/vmstat`. | Linux

watchdog | Exposes statistics from `/sys/class/watchdog` | Linux

xfs | Exposes XFS runtime statistics. | Linux (kernel 4.4+)

zfs | Exposes [ZFS](http://open-zfs.org/) performance statistics. | FreeBSD, [Linux](http://zfsonlinux.org/), Solaris

`node_exporter` also implements a number of collectors that are disabled by default. Reasons for this vary by

collector, and may include:

* High cardinality

* Prolonged runtime that exceeds the Prometheus `scrape_interval` or `scrape_timeout`

* Significant resource demands on the host

You can enable additional collectors as desired by adding them to your

init system's or service supervisor's startup configuration for

`node_exporter` but caution is advised. Enable at most one at a time,

testing first on a non-production system, then by hand on a single

production node. When enabling additional collectors, you should

carefully monitor the change by observing the `

scrape_duration_seconds` metric to ensure that collection completes

and does not time out. In addition, monitor the

`scrape_samples_post_metric_relabeling` metric to see the changes in

cardinality.

| Name | Description | OS |

| -------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------ |

| buddyinfo | Exposes statistics of memory fragments as reported by /proc/buddyinfo. | Linux |

| cgroups | A summary of the number of active and enabled cgroups | Linux |

| cpu\_vulnerabilities | Exposes CPU vulnerability information from sysfs. | Linux |

| devstat | Exposes device statistics | Dragonfly, FreeBSD |

| drm | Expose GPU metrics using sysfs / DRM, `amdgpu` is the only driver which exposes this information through DRM | Linux |

| drbd | Exposes Distributed Replicated Block Device statistics (to version 8.4) | Linux |

| ethtool | Exposes network interface information and network driver statistics equivalent to `ethtool`, `ethtool -S`, and `ethtool -i`. | Linux |

| interrupts | Exposes detailed interrupts statistics. | Linux, OpenBSD |

| ksmd | Exposes kernel and system statistics from `/sys/kernel/mm/ksm`. | Linux |

| lnstat | Exposes stats from `/proc/net/stat/`. | Linux |

| logind | Exposes session counts from [logind](http://www.freedesktop.org/wiki/Software/systemd/logind/). | Linux |

| meminfo\_numa | Exposes memory statistics from `/sys/devices/system/node/node[0-9]*/meminfo`, `/sys/devices/system/node/node[0-9]*/numastat`. | Linux |

| mountstats | Exposes filesystem statistics from `/proc/self/mountstats`. Exposes detailed NFS client statistics. | Linux |

| network_route | Exposes the routing table as metrics | Linux |

| perf | Exposes perf based metrics (Warning: Metrics are dependent on kernel configuration and settings). | Linux |

| processes | Exposes aggregate process statistics from `/proc`. | Linux |

| qdisc | Exposes [queuing discipline](https://en.wikipedia.org/wiki/Network_scheduler#Linux_kernel) statistics | Linux |

| slabinfo | Exposes slab statistics from `/proc/slabinfo`. Note that permission of `/proc/slabinfo` is usually 0400, so set it appropriately. | Linux |

| softirqs | Exposes detailed softirq statistics from `/proc/softirqs`. | Linux |

| sysctl | Expose sysctl values from `/proc/sys`. Use `--collector.sysctl.include(-info)` to configure. | Linux |

| systemd | Exposes service and system status from [systemd](http://www.freedesktop.org/wiki/Software/systemd/). | Linux |

| tcpstat | Exposes TCP connection status information from `/proc/net/tcp` and `/proc/net/tcp6`. (Warning: the current version has potential performance issues in high load situations.) | Linux |

| wifi | Exposes WiFi device and station statistics. | Linux |

| xfrm | Exposes statistics from `/proc/net/xfrm_stat` | Linux |

| zoneinfo | Exposes NUMA memory zone metrics. | Linux |

kube-prometheus中node-exporter的配置如下

apiVersion: apps/v1

kind: DaemonSet

metadata:

labels:

app.kubernetes.io/component: exporter

app.kubernetes.io/name: node-exporter

app.kubernetes.io/part-of: kube-prometheus

app.kubernetes.io/version: 1.1.2

name: node-exporter

namespace: monitor

spec:

selector:

matchLabels:

app.kubernetes.io/component: exporter

app.kubernetes.io/name: node-exporter

app.kubernetes.io/part-of: kube-prometheus

template:

metadata:

labels:

app.kubernetes.io/component: exporter

app.kubernetes.io/name: node-exporter

app.kubernetes.io/part-of: kube-prometheus

app.kubernetes.io/version: 1.1.2

spec:

# 调度优先级为 **高优先级的 PriorityClass** - 在资源不足时，低优先级的 Pod 可能会被**驱逐（evicted）**，以腾出资源给高优先级 Pod。

priorityClassName: system-cluster-critical

containers:

- args:

# 只监听 127.0.0.1 eth0的 ip 留给代理进行监听，这样就能只使用一个端口，代理和node-export使用一个端口

- --web.listen-address=127.0.0.1:9100

# 在容器环境中，会将 /sys 挂载到 /host/sys

- --path.sysfs=/host/sys

# 在容器中将 / 挂载到目录 /host/root

- --path.rootfs=/host/root

# wifi相关数据不采集

- --no-collector.wifi

# 硬件数据采集被禁止，容器环境中没有特权很多容器内部的数据无法采集

- --no-collector.hwmon

# 部分文件挂载点不被采集

- --collector.filesystem.ignored-mount-points=^/(dev|proc|sys|var/lib/docker/.+|var/lib/kubelet/pods/.+)($|/)

# veth开头的网卡不采集数据，这些网卡时虚拟网卡

- --collector.netclass.ignored-devices=^(veth.*)$

# 已经采集的数据中排除对应的指标

- --collector.netdev.device-exclude=^(veth.*)$

image: HARBOR_ADDR/quay.io/prometheus/node-exporter:v1.1.2

name: node-exporter

resources:

limits:

cpu: 250m

memory: 180Mi

requests:

cpu: 102m

memory: 180Mi

volumeMounts:

- mountPath: /host/sys

mountPropagation: HostToContainer

name: sys

readOnly: true

- mountPath: /host/root

mountPropagation: HostToContainer

name: root

readOnly: true

- args:

- --logtostderr

# k8s 实现的环境变量注入，当启动过程中，k8s会根据需要从 fieldRef 将变量值提取出来，并进行替换

- --secure-listen-address=[$(IP)]:9100

- --tls-cipher-suites=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305

# 监听的数据流

- --upstream=http://127.0.0.1:9100/

env:

- name: IP

valueFrom:

fieldRef:

fieldPath: status.podIP

image: HARBOR_ADDR/quay.io/brancz/kube-rbac-proxy:v0.8.0

name: kube-rbac-proxy

ports:

- containerPort: 9100

hostPort: 9100

name: https

resources:

limits:

cpu: 20m

memory: 40Mi

requests:

cpu: 10m

memory: 20Mi

securityContext:

runAsGroup: 65532

runAsNonRoot: true

runAsUser: 65532

hostNetwork: true

hostPID: true

nodeSelector:

kubernetes.io/os: linux

securityContext:

runAsNonRoot: true

runAsUser: 65534

serviceAccountName: node-exporter

tolerations:

- operator: Exists

volumes:

- hostPath:

path: /sys

name: sys

- hostPath:

path: /

name: root

updateStrategy:

rollingUpdate:

maxUnavailable: 10%

type: RollingUpdate