Getting Readiness & Liveliness Probe Failed: Http Probe Failed with Statuscode: 503 During Starting of Varnish Using Helm Chart Kubernetes”
I Am Trying to Create a Helm Chart for Varnish to Be Deployed/Run on Kubernetes Cluster. While Running the Helm Package Which Has Varnish Image from Docker...
I am trying to create a Helm chart for varnish to be deployed/run on Kubernetes cluster. While running the helm package which has varnish image from Docker community its throwing error
Readiness probe failed: HTTP probe failed with statuscode: 503
Liveness probe failed: HTTP probe failed with statuscode: 503
Have shared values.yaml, deployment.yaml, varnish-config.yaml, varnish.vcl.
Any solution approached would be welcomed....
Values.yaml:
# Default values for tt.
# This is a YAML-formatted file.
# Declare variables to be passed into your templates.
replicaCount: 1
#vcl 4.0;
#import std;
#backend default {
# .host = "";
# .port = "80";
# .first_byte_timeout = 60s;
# .connect_timeout = 300s;
#}
varnishBackendService: ""
varnishBackendServicePort: "80"
image:
repository: varnish
tag: 6.0.6
pullPolicy: IfNotPresent
nameOverride: ""
fullnameOverride: ""
service:
type: ClusterIP
port: 80
#probes:
# enabled: true
ingress:
enabled: false
annotations: {}
# nginx
# "true"
path: /
hosts:
- chart-example.local
tls: []
# - secretName: chart-example-tls
# hosts:
# - chart-example.local
resources:
limits:
memory: 128Mi
requests:
memory: 64Mi
#resources: {}
# We usually recommend not to specify default resources and to leave this as a conscious
# choice for the user. This also increases chances charts run on environments with little
# resources, such as Minikube. If you do want to specify resources, uncomment the following
# lines, adjust them as necessary, and remove the curly braces after 'resources:'.
# limits:
# cpu: 100m
# memory: 128Mi
# requests:
# cpu: 100m
# memory: 128Mi
nodeSelector: {}
tolerations: []
affinity: {}
Deployment.yaml:
apiVersion: apps/v1beta2
kind: Deployment
metadata:
name: {{ include "varnish.fullname" . }}
labels:
app: {{ include "varnish.name" . }}
chart: {{ include "varnish.chart" . }}
release: {{ .Release.Name }}
heritage: {{ .Release.Service }}
spec:
replicas: {{ .Values.replicaCount }}
selector:
matchLabels:
app: {{ include "varnish.name" . }}
release: {{ .Release.Name }}
template:
metadata:
labels:
app: {{ include "varnish.name" . }}
release: {{ .Release.Name }}
# annotations:
# "true"
spec:
volumes:
- name: varnish-config
configMap:
name: {{ include "varnish.fullname" . }}-varnish-config
items:
- key: default.vcl
path: default.vcl
containers:
- name: {{ .Chart.Name }}
image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
imagePullPolicy: {{ .Values.image.pullPolicy }}
env:
- name: VARNISH_VCL
value: /etc/varnish/default.vcl
volumeMounts:
- name: varnish-config
mountPath : /etc/varnish/
ports:
- name: http
containerPort: 80
protocol: TCP
targetPort: 80
livenessProbe:
httpGet:
path: /healthcheck
port: http
port: 80
failureThreshold: 3
initialDelaySeconds: 45
timeoutSeconds: 10
periodSeconds: 20
readinessProbe:
httpGet:
path: /healthcheck
port: http
port: 80
initialDelaySeconds: 10
timeoutSeconds: 15
periodSeconds: 5
restartPolicy: "Always"
resources:
{{ toYaml .Values.resources | indent 12 }}
{{- with .Values.nodeSelector }}
nodeSelector:
{{ toYaml . | indent 8 }}
{{- end }}
{{- with .Values.affinity }}
affinity:
{{ toYaml . | indent 8 }}
{{- end }}
{{- with .Values.tolerations }}
tolerations:
{{ toYaml . | indent 8 }}
{{- end }}
vanrnish-config.yaml:
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ template "varnish.fullname" . }}-varnish-config
labels:
app: {{ template "varnish.fullname" . }}
chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
release: "{{ .Release.Name }}"
heritage: "{{ .Release.Service }}"
data:
default.vcl: |-
{{ $file := (.Files.Get "config/varnish.vcl") }}
{{ tpl $file . | indent 4 }}
varnish.vcl:
# VCL version 5.0 is not supported so it should be 4.0 or 4.1 even though actually used Varnish version is 6
vcl 4.1;
import std;
# The minimal Varnish version is 5.0
# For SSL offloading, pass the following header in your proxy server or load balancer: 'X-Forwarded-Proto: https'
backend default {
#.host = "{{ default "google.com" .Values.varnishBackendService }}";
.host = "{{ .Values.varnishBackendService }}";
.port = "{{ .Values.varnishBackendServicePort }}";
#.port = "{{ default "80" .Values.varnishBackendServicePort }}";
.first_byte_timeout = 60s;
.connect_timeout = 300s ;
.probe = {
.url = "/";
.timeout = 1s;
.interval = 5s;
.window = 5;
.threshold = 3;
}
}
backend server2 {
.host = "74.125.24.105:80";
.probe = {
.url = "/";
.timeout = 1s;
.interval = 5s;
.window = 5;
.threshold = 3;
}
}
import directors;
sub vcl_init {
new vdir = directors.round_robin();
vdir.add_backend(default);
vdir.add_backend(server2);
}
#sub vcl_recv {
# if (req.url ~ "/healthcheck"){
# error 200 "imok";
# set req.http.Connection = "close";
# }
#}
1 Answer
The fact that Kubernetes returns an HTTP 503 error for both the readiness & the liveliness probes means that there's probably something wrong with the connection to your backend.
Interestingly, that's besides the point. Those probes aren't there to perform an end-to-end test of your HTTP flow. The probes are only there to verify if the service they are monitoring is responding.
That's why you can just return a synthetic HTTP response when capturing requests that point to /healthcheck.
Here's the VCL code to do it:
sub vcl_recv {
if(req.url == "/healthcheck") {
return(synth(200,"OK"));
}
}
That doesn't explain the fact why you're getting an HTTP 503 error, but at least, the probes will work.
David Miller brings 15 years of experience in global economics, personal finance strategy, and market dynamics. He specializes in turning complex economic trends into actionable insights for everyday readers.
