Incorrect liveness probe for Redis not failing - kubernetes

Question

I have configured a liveness probe for my Redis instances that makes sure that the Redis is able to retrieve keys for it to be able to be called 'alive'.
livenessProbe:
initialDelaySeconds: 20
periodSeconds: 10
exec:
command:
{{- include "liveness_probe" . | nindent 16 }}
_liveness.tpl
{{/* Liveness probe script. */}}
{{- define "liveness_probe" -}}
- "redis-cli"
- "set"
- "liveness_test_key"
- "\"SUCCESS\""
- "&&"
- "redis-cli"
- "get"
- "liveness_test_key"
- "|"
- "awk"
- "'$1 != \"SUCCESS\" {exit 1}'"
{{- end }}
The pod is able to start after doing the change. However, I would like to make sure that the probe is working as expected. For that I just added a delete command before the get command.
{{/* Liveness probe script. */}}
{{- define "liveness_probe" -}}
- "redis-cli"
- "set"
- "liveness_test_key"
- "\"SUCCESS\""
- "&&"
- "redis-cli"
- "del"
- "liveness_test_key"
- "&&"
- "redis-cli"
- "get"
- "liveness_test_key"
- "|"
- "awk"
- "'$1 != \"SUCCESS\" {exit 1}'"
{{- end }}
I get the expected exit codes when I execute this command directly in my command prompt.
But the thing is that my pod is still able to start.
Is the liveness probe command I am using okay? If so, how do I verify this?

Answer 1

Try this for your liveness probe it is working fine and you can try the same in readinessProbe:
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: redis
name: redis
spec:
replicas: 1
selector:
matchLabels:
app: redis
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: redis
spec:
containers:
- image: redis
name: redis
livenessProbe:
exec:
command:
- sh
- -c
- |
#!/usr/bin/env bash -e
#export REDISCLI_AUTH="$REDIS_PASSWORD"
set_response=$(
redis-cli set liveness_test_key "SUCCESS"
)
del_response=$(
redis-cli del liveness_test_key
)
response=$(
redis-cli get liveness_test_key
)
if [ "$response" != "SUCCESS" ] ; then
echo "Unable to get keys, something is wrong"
exit 1
fi
initialDelaySeconds: 5
periodSeconds: 5
status: {}
You will need to edit these values in your template

Answer 2

I think you're confusing livenessProbewith readinessProbe. livenessProbe tells kubernetes to restart your pod if your command returns a non-zero exit code, this is executed after the period specified in initialDelaySeconds: 20
Whereas readinessProbe is what decides whether a pod is in Ready state to accept traffict or not.
readinessProbe:
initialDelaySeconds: 20
periodSeconds: 10
exec:
command:
{{- include "liveness_probe" . | nindent 16 }}
They can also be used together if you need so.
Please check this page from kubernetes documentation where they explain livenessProbe, readinessProbe and startupProbe