Logging&Monitoring.md

Logging/Monitoring (5%)

kubernetes.io > Documentation > Tasks > Monitor, Logging & Debugging > Monitor Node Health

kubernetes.io > Documentation > Tasks > Monitor, Logging & Debugging > Tools for Monitoring Resources

kubernetes.io > Documentation > Concepts > Workloads > Pods > Pod Lifecycle

kubernetes.io > Documentation > Tasks > Configure Pods & Containers > Configure Liveness and Readiness Probes

kubernetes.io > Documentation > Reference > logs

Understand how to monitor all cluster components

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$ git clone https://github.com/kubernetes-incubator/metrics-server.git
$ kubectl creare -f deploy/1.8+/
$ kubectl top node
$ kubectl top pod

Understand how to monitor applications

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Create a YAML:

$ cat exec-liveness.yaml

apiVersion: v1
kind: Pod
metadata:
  labels:
    test: liveness
  name: liveness-exec
spec:
  containers:
  - name: liveness
    image: k8s.gcr.io/busybox
    args:
    - /bin/sh
    - -c
    - touch /tmp/healthy; sleep 30; rm -rf /tmp/healthy; sleep 600
    livenessProbe:
      exec:
        command:
        - cat
        - /tmp/healthy
      initialDelaySeconds: 5
      periodSeconds: 5

$ cat exec-readyness.yaml

apiVersion: v1
kind: Pod
metadata:
  labels:
    test: liveness
  name: liveness-exec
spec:
  containers:
  - name: liveness
    image: k8s.gcr.io/busybox
    args:
    - /bin/sh
    - -c
    - touch /tmp/healthy; sleep 30; rm -rf /tmp/healthy; sleep 600
    readinessProbe:
      exec:
        command:
        - cat
        - /tmp/healthy
      initialDelaySeconds: 5
      periodSeconds: 5

Manage cluster component logs

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containerised components log under /var/log

Master (/var/log or /var/log/containers)
       /var/log/kube-apiserver.log – API Server, responsible for serving the API
       /var/log/kube-scheduler.log – Scheduler, responsible for making scheduling decisions
       /var/log/kube-controller-manager.log – Controller that manages replication controllers

Worker Nodes (/var/log or /var/log/containers)
                /var/log/kubelet.log – Kubelet, responsible for running containers on the node
                /var/log/kube-proxy.log – Kube Proxy, responsible for service load balancing

Manage application logs

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$ docker run kodecloud/event-simulator
$ docker run -d kodecloud/event-simulator
$ docker logs -f ecf

$ cat event-simulator.yaml

apiVersion: v1
kind: Pod
metadata:
  name: event-pod
spec:
  containers:
  - image: kodecloud/event-simulator
    name: event-simulator
  - image: nginx
    name: nginx
    
$ kubectl create -f event-simulator.yaml
$ kubectl logs -f event-pod
$ kubectl logs -f event-pod event-simulator