Nagios-style checks against Kubernetes API. Designed for usage with Nagios, Icinga, Zabbix... Whatever.
Usage $0 [-m <MODE>|-h] [-o <TIMEOUT>] [-H <APISERVER> [-T <TOKEN>|-t <TOKENFILE>]] [-K <KUBE_CONFIG>]
[-N <NAMESPACE>] [-n <NAME>] [-w <WARN>] [-c <CRIT>] [-v]
Options are:
-m MODE Which check to perform
-H APISERVER API URL to query, kubectl is used if this option is not set
-T TOKEN Authorization token for API
-t TOKENFILE Path to file with token in it
-K KUBE_CONFIG Path to kube-config file for kubectl utility
-N NAMESPACE Optional namespace for some modes. By default all namespaces will be used
-n NAME Optional deployment name or pod app label depending on the mode being used. By default all objects will be checked
-o TIMEOUT Timeout in seconds; default is 15
-w WARN Warning threshold for
- TLS expiration days for TLS mode; default is 30
- Pod restart count in pods mode; default is 30
- Job failed count in jobs mode; default is 1
- Pvc storage utilization; default is 80%
- API cert expiration days for apicert mode; default is 30
-c CRIT Critical threshold for
- Pod restart count (in pods mode); default is 150
- Unbound Persistent Volumes in unboundpvs mode; default is 5
- Job failed count in jobs mode; default is 2
- Pvc storage utilization; default is 90%
- API cert expiration days for apicert mode; default is 15
-M EXIT_CODE Exit code when resource is missing; default is 2 (CRITICAL)
-v Show current Version
-h Show this help and exit
Modes are:
apiserver Not for kubectl, should be used for each apiserver independently
apicert Check the apicert expiration date
nodes Check for active nodes
daemonsets Check for daemonsets readiness
deployments Check for deployments availability
jobs Check for failed jobs
pods Check for restart count of containters in the pods
replicasets Check for replicasets readiness
statefulsets Check for statefulsets readiness
tls Check for tls secrets expiration dates
pvc Check for pvc utilization
unboundpvs Check for unbound persistent volumes.
components Check for health of k8s components (Deprecated in K8s 1.19+)Check apiserver health using tokenfile:
./check_kubernetes.sh -m apiserver -H https://<...>:6443 -t /path/to/tokenfile
OK. Kubernetes apiserver health is OKCheck whether all deployments are available using token:
./check_kubernetes.sh -m deployments -H https://<...>:6443 -T eYN6...
OK. 27 deploymens are availableCheck one definite deployment using kubectl:
./check_kubernetes.sh -m deployments -K /path/to/kube_config -N ingress-nginx -n nginx-ingress-controller
OK. Deployment availableCheck nodes using kubectl with default kube config:
./check_kubernetes.sh -m nodes -H https://<...>:6443
OK. 4 nodes are ReadyCheck pods (by the restarts count):
./check_kubernetes.sh -m pods -H https://<...>:6443 -N kube-system -w 5
WARNING. Container kube-system/calico-node-5kc4n/calico-node: 6 restarts. 22 pods ready, 0 pods not readyCheck daemonstets (compare number of desired and number of ready pods):
./check_kubernetes.sh -m daemonsets -K ~/.kube/cluster -N monitoring
OK. Daemonset monitoring/node-exporter 5/5 readyCheck replicasets (compare number of desired and number of ready pods):
./check_kubernetes.sh -m replicasets -K ~/.kube/cluster -N monitoring
OK. Replicaset monitoring/node-exporter 5/5 readyCheck statefulsets (compare number of desired and number of ready pods):
./check_kubernetes.sh -m statefulsets -K ~/.kube/cluster -N monitoring
OK. Statefulset monitoring/node-exporter 5/5 readyCheck TLS certs:
./check_kubernetes.sh -m tls -H https://<...>:6443 -T $TOKEN -N kube-system
kube-system/k8s-local-cert is about to expire in 18 daysCheck failed jobs with any name:
./check_kubernetes.sh -m jobs
CRITICAL. Job bad has 5 failures. Job bad2 has 4 failures. 9 jobs in total have failedChecked failed jobs named 'good':
./check_kubernetes.sh -m jobs -n good
OK: 0 failed jobs is below thresholdCheck utilization if pvc (if consumes more than %):
./check_kubernetes.sh -m pvc
CRITICAL. Very high storage utilization on pvc prometheus-data: 93% (86106636288/157459890176 Bytes)Check expiration date for API TLS certificate: ./check_kubernetes.sh -m apicert -H https://<...>:6443 -T $TOKEN OK. API cert expires in 278 days
All modes support the -b brief option. In this mode, a single numerical output is returned. The number is positive on success and zero or negative on error.
For boolean checks, 1 is returned on success and 0 on error.
For numerical checks, the number is returned on success and zero or a negative number on error. For example, when used with pods, the number of pods is returned, but minus the number of restarts if it exceeds the warning threshold (so if 3 pods are ok and 1 failed, 3 is returned, but if 4 pods are ok with none failed but 157 restarts with default settings, -157 is returned). Sometimes positivity suffices, sometimes you need to monitor the exact number.
All the needed objects (ServiceAccount, Secret, ClusterRole, RoleBinding) can be created by Terraform with terraform.tf file or with this command:
kubectl apply -f https://raw.githubusercontent.com/agapoff/check_kubernetes/master/account.yamlFor mode pvc or tls you need to enable the permissions in the yaml first. Those two can have security implications and are thus disabled by default.
Then in order to get the token just issue this command:
kubectl -n monitoring get secret monitoring -o "jsonpath={.data.token}" | openssl enc -d -base64 -ACommand:
object CheckCommand "check-kubernetes" {
import "plugin-check-command"
command = [ PluginDir + "/check_kubernetes.sh" ]
arguments = {
"-H" = "$kube_apiserver$"
"-m" = "$kube_mode$"
"-o" = "$kube_timeout$"
"-T" = "$kube_pass$"
"-t" = "$kube_tokenfile$"
"-K" = "$kube_config$"
"-N" = "$kube_ns$"
"-n" = "$kube_name$"
"-w" = "$kube_warn$"
"-c" = "$kube_crit$"
}
vars.kube_host = "$host.address$"
vars.kube_port = 6443
vars.kube_scheme = "https"
vars.kube_apiserver = "$kube_scheme$://$kube_host$:$kube_port$"
}Services:
apply Service "k8s apiserver health" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "apiserver"
assign where "k8s-master" in host.vars.roles
}
apply Service "k8s components health" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "components"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s nodes" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "nodes"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s deployments" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "deployments"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s daemonsets" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "daemonsets"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s replicasets" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "replicasets"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s TLS certs" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "tls"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s pvc" {
import "generic-service"
check_interval = 1h
check_command = "check-kubernetes"
vars.kube_mode = "pvc"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s pods" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "pods"
assign where "k8s-api" in host.vars.roles
}
apply Service "k8s ingress controller" {
import "generic-service"
check_command = "check-kubernetes"
vars.kube_mode = "deployments"
vars.kube_ns = "ingress-nginx"
vars.kube_name = "nginx-ingress-controller"
assign where "k8s-api" in host.vars.roles
}Host template:
template Host "k8s-host" {
import "generic-host"
vars.kube_pass = "..."
vars.kube_scheme = "https"
vars.kube_port = 6443
}Hosts:
# VIP address of the API
object Host "k8s-api" {
import "k8s-host"
address = "<...>"
vars.roles = [ "k8s-api" ]
}
object Host "k8s-master1" {
import "linux-host"
import "k8s-host"
address = "<...>"
vars.roles = [ "k8s-master" ]
}