ipedrazas

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: mynamespace-user
  namespace: mynamespace

---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1beta1

ipedrazas

// Generated by https://quicktype.io

type Deployment struct {
	APIVersion string             `json:"apiVersion"`
	Kind       string             `json:"kind"`      
	Metadata   DeploymentMetadata `json:"metadata"`  
	Spec       DeploymentSpec     `json:"spec"`      
	Status     Status             `json:"status"`    

ipedrazas

cat <<EOF | istioctl replace -f -
apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: ubuntu-archive-ext
spec:
  hosts:
  - archive.ubuntu.com
  - security.ubuntu.com
  ports:

ipedrazas

Pods have a big number of restarts

NAME                                     READY     STATUS    RESTARTS   AGE
details-v1-6798fccf5f-t7zqc              2/2       Running   0          22h
productpage-v1-5f7b97679-gn2js           2/2       Running   190        22h
ratings-v1-5675c99f79-66c96              2/2       Running   0          22h
reviews-v1-586cb488f9-cjxxz              2/2       Running   190        17h
reviews-v2-67ccbd89c7-4jgcr              2/2       Running   242        1d
reviews-v3-6fd9fddb9f-mczvf              2/2       Running   190        17h

ipedrazas

Debugging in Kubernetes

"How do you debug applications running in Kubernetes?"

The strategy to successfully debugging applications in kubernetes is to be consistent with your approach: application to public traffic or public traffic to application.

The question as it is it's very generic, however, let's see the different components we might have to check in our debugging journey:

• Container/Pod
• Service

ipedrazas

// https://github.com/stefanprodan/k8s-podinfo/blob/master/pkg/server/instrument.go

func NewInstrument() *Instrument {
	// used for monitoring and alerting (RED method)
	histogram := prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Subsystem: "http",
		Name:      "requests",
		Help:      "Seconds spent serving HTTP requests.",
		Buckets:   prometheus.DefBuckets,
	}, []string{"method", "path", "status"})

ipedrazas

kubectl run my-shell --rm -i --tty --image ubuntu --serviceaccount tiller --namespace kube-system -- bash 

ipedrazas

// setup a signal hander to gracefully exit
func sigHandler() <-chan struct{} {
	stop := make(chan struct{})
	go func() {
		c := make(chan os.Signal, 1)
		signal.Notify(c,
			syscall.SIGINT,  // Ctrl+C
			syscall.SIGTERM, // Termination Request
			syscall.SIGSEGV, // FullDerp
			syscall.SIGABRT, // Abnormal termination

ipedrazas

gcloud beta container \
--project "kubernetes-prototype-197913" \
clusters create "lab-1" \
--zone "europe-west2-a" \
--username "admin" \
--cluster-version "1.9.6-gke.0" \
--machine-type "n1-standard-1" \
--image-type "COS" \
--disk-size "100" \
--node-labels expiry=20180411,env=lab \

ipedrazas

kubectl get pods --all-namespaces -o json  \
| jq -r '.items[] | \
select(.status.phase != "Running" or ([ .status.conditions[] | \
select(.type == "Ready" and .state == false) ] | length ) == 1 ) | \
.metadata.namespace + "/" + .metadata.name'