WHAT： 从 Prometheus server 端接收到 alerts 后，会进行去除重复数据，分组，并路由到对方的接受方式，发出报警。常见的接收方式有：电子邮件，pagerduty 等。
WHY：使得系统的警告随时让我们知道
# 200机器，准备镜像、资源清单：
~]# mkdir /data/k8s-yaml/alertmanager
~]# cd /data/k8s-yaml/alertmanager
alertmanager]# docker pull docker.io/prom/alertmanager:v0.14.0
# 注意，这里你如果不用14版本可能会报错
alertmanager]# docker images|grep alert
alertmanager]# docker tag 23744b2d645c harbor.od.com/infra/alertmanager:v0.14.0
alertmanager]# docker push harbor.od.com/infra/alertmanager:v0.14.0
# 注意下面记得修改成你自己的邮箱等信息，还有中文注释可以删掉
alertmanager]# vi cm.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: alertmanager-config
namespace: infra
data:
config.yml: |-
global:
# 在没有报警的情况下声明为已解决的时间
resolve_timeout: 5m
# 配置邮件发送信息
smtp_smarthost: 'smtp.163.com:25'
smtp_from: 'ben909336740@163.com'
smtp_auth_username: 'ben909336740@163.com'
smtp_auth_password: 'xxxxxx'
smtp_require_tls: false
# 所有报警信息进入后的根路由，用来设置报警的分发策略
route:
# 这里的标签列表是接收到报警信息后的重新分组标签，例如，接收到的报警信息里面有许多具有 cluster=A 和 alertname=LatncyHigh 这样的标签的报警信息将会批量被聚合到一个分组里面
group_by: ['alertname', 'cluster']
# 当一个新的报警分组被创建后，需要等待至少group_wait时间来初始化通知，这种方式可以确保您能有足够的时间为同一分组来获取多个警报，然后一起触发这个报警信息。
group_wait: 30s
# 当第一个报警发送后，等待'group_interval'时间来发送新的一组报警信息。
group_interval: 5m
# 如果一个报警信息已经发送成功了，等待'repeat_interval'时间来重新发送他们
repeat_interval: 5m
# 默认的receiver：如果一个报警没有被一个route匹配，则发送给默认的接收器
receiver: default
receivers:
- name: 'default'
email_configs:
- to: '909336740@qq.com'
send_resolved: true
alertmanager]# vi dp.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: alertmanager
namespace: infra
spec:
replicas: 1
selector:
matchLabels:
app: alertmanager
template:
metadata:
labels:
app: alertmanager
spec:
containers:
- name: alertmanager
image: harbor.od.com/infra/alertmanager:v0.14.0
args:
- "--config.file=/etc/alertmanager/config.yml"
- "--storage.path=/alertmanager"
ports:
- name: alertmanager
containerPort: 9093
volumeMounts:
- name: alertmanager-cm
mountPath: /etc/alertmanager
volumes:
- name: alertmanager-cm
configMap:
name: alertmanager-config
imagePullSecrets:
- name: harbor
alertmanager]# vi svc.yaml
apiVersion: v1
kind: Service
metadata:
name: alertmanager
namespace: infra
spec:
selector:
app: alertmanager
ports:
- port: 80
targetPort: 9093
# 22机器，应用清单：
~]# kubectl apply -f http://k8s-yaml.od.com/alertmanager/cm.yaml
~]# kubectl apply -f http://k8s-yaml.od.com/alertmanager/dp.yaml
~]# kubectl apply -f http://k8s-yaml.od.com/alertmanager/svc.yaml
# 200机器，配置报警规则：
~]# vi /data/nfs-volume/prometheus/etc/rules.yml
groups:
- name: hostStatsAlert
rules:
- alert: hostCpuUsageAlert
expr: sum(avg without (cpu)(irate(node_cpu{mode!='idle'}[5m]))) by (instance) > 0.85
for: 5m
labels:
severity: warning
annotations:
summary: "{{ $labels.instance }} CPU usage above 85% (current value: {{ $value }}%)"
- alert: hostMemUsageAlert
expr: (node_memory_MemTotal - node_memory_MemAvailable)/node_memory_MemTotal > 0.85
for: 5m
labels:
severity: warning
annotations:
summary: "{{ $labels.instance }} MEM usage above 85% (current value: {{ $value }}%)"
- alert: OutOfInodes
expr: node_filesystem_free{fstype="overlay",mountpoint ="/"} / node_filesystem_size{fstype="overlay",mountpoint ="/"} * 100 < 10
for: 5m
labels:
severity: warning
annotations:
summary: "Out of inodes (instance {{ $labels.instance }})"
description: "Disk is almost running out of available inodes (< 10% left) (current value: {{ $value }})"
- alert: OutOfDiskSpace
expr: node_filesystem_free{fstype="overlay",mountpoint ="/rootfs"} / node_filesystem_size{fstype="overlay",mountpoint ="/rootfs"} * 100 < 10
for: 5m
labels:
severity: warning
annotations:
summary: "Out of disk space (instance {{ $labels.instance }})"
description: "Disk is almost full (< 10% left) (current value: {{ $value }})"
- alert: UnusualNetworkThroughputIn
expr: sum by (instance) (irate(node_network_receive_bytes[2m])) / 1024 / 1024 > 100
for: 5m
labels:
severity: warning
annotations:
summary: "Unusual network throughput in (instance {{ $labels.instance }})"
description: "Host network interfaces are probably receiving too much data (> 100 MB/s) (current value: {{ $value }})"
- alert: UnusualNetworkThroughputOut
expr: sum by (instance) (irate(node_network_transmit_bytes[2m])) / 1024 / 1024 > 100
for: 5m
labels:
severity: warning
annotations:
summary: "Unusual network throughput out (instance {{ $labels.instance }})"
description: "Host network interfaces are probably sending too much data (> 100 MB/s) (current value: {{ $value }})"
- alert: UnusualDiskReadRate
expr: sum by (instance) (irate(node_disk_bytes_read[2m])) / 1024 / 1024 > 50
for: 5m
labels:
severity: warning
annotations:
summary: "Unusual disk read rate (instance {{ $labels.instance }})"
description: "Disk is probably reading too much data (> 50 MB/s) (current value: {{ $value }})"
- alert: UnusualDiskWriteRate
expr: sum by (instance) (irate(node_disk_bytes_written[2m])) / 1024 / 1024 > 50
for: 5m
labels:
severity: warning
annotations:
summary: "Unusual disk write rate (instance {{ $labels.instance }})"
description: "Disk is probably writing too much data (> 50 MB/s) (current value: {{ $value }})"
- alert: UnusualDiskReadLatency
expr: rate(node_disk_read_time_ms[1m]) / rate(node_disk_reads_completed[1m]) > 100
for: 5m
labels:
severity: warning
annotations:
summary: "Unusual disk read latency (instance {{ $labels.instance }})"
description: "Disk latency is growing (read operations > 100ms) (current value: {{ $value }})"
- alert: UnusualDiskWriteLatency
expr: rate(node_disk_write_time_ms[1m]) / rate(node_disk_writes_completedl[1m]) > 100
for: 5m
labels:
severity: warning
annotations:
summary: "Unusual disk write latency (instance {{ $labels.instance }})"
description: "Disk latency is growing (write operations > 100ms) (current value: {{ $value }})"
- name: http_status
rules:
- alert: ProbeFailed
expr: probe_success == 0
for: 1m
labels:
severity: error
annotations:
summary: "Probe failed (instance {{ $labels.instance }})"
description: "Probe failed (current value: {{ $value }})"
- alert: StatusCode
expr: probe_http_status_code <= 199 OR probe_http_status_code >= 400
for: 1m
labels:
severity: error
annotations:
summary: "Status Code (instance {{ $labels.instance }})"
description: "HTTP status code is not 200-399 (current value: {{ $value }})"
- alert: SslCertificateWillExpireSoon
expr: probe_ssl_earliest_cert_expiry - time() < 86400 * 30
for: 5m
labels:
severity: warning
annotations:
summary: "SSL certificate will expire soon (instance {{ $labels.instance }})"
description: "SSL certificate expires in 30 days (current value: {{ $value }})"
- alert: SslCertificateHasExpired
expr: probe_ssl_earliest_cert_expiry - time() <= 0
for: 5m
labels:
severity: error
annotations:
summary: "SSL certificate has expired (instance {{ $labels.instance }})"
description: "SSL certificate has expired already (current value: {{ $value }})"
- alert: BlackboxSlowPing
expr: probe_icmp_duration_seconds > 2
for: 5m
labels:
severity: warning
annotations:
summary: "Blackbox slow ping (instance {{ $labels.instance }})"
description: "Blackbox ping took more than 2s (current value: {{ $value }})"
- alert: BlackboxSlowRequests
expr: probe_http_duration_seconds > 2
for: 5m
labels:
severity: warning
annotations:
summary: "Blackbox slow requests (instance {{ $labels.instance }})"
description: "Blackbox request took more than 2s (current value: {{ $value }})"
- alert: PodCpuUsagePercent
expr: sum(sum(label_replace(irate(container_cpu_usage_seconds_total[1m]),"pod","$1","container_label_io_kubernetes_pod_name", "(.*)"))by(pod) / on(pod) group_right kube_pod_container_resource_limits_cpu_cores *100 )by(container,namespace,node,pod,severity) > 80
for: 5m
labels:
severity: warning
annotations:
summary: "Pod cpu usage percent has exceeded 80% (current value: {{ $value }}%)"
# 在最后面添加如下内容
~]# vi /data/nfs-volume/prometheus/etc/prometheus.yml
alerting:
alertmanagers:
- static_configs:
- targets: ["alertmanager"]
rule_files:
- "/data/etc/rules.yml"
rules.yml文件 ：这个文件就是报警规则
这时候可以重启Prometheus的pod，但生产商因为Prometheus太庞大，删掉容易拖垮集群，所以我们用另外一种方法，平滑加载（Prometheus支持）：
# 21机器，因为我们起的Prometheus是在21机器，平滑加载:
~]# ps aux|grep prometheus
~]# kill -SIGHUP 1488
这时候报警规则就都有了