How to refer whole structure from values.yaml instead of specifying one by one? - kubernetes

Question

I am trying to deploy helm chart in local vritual box on minikube using helm command shown below.
I am referring livenessProbe , readinessProbe configuration directly from values.yam in the deployment.yaml as shown below. However following this approach gives me the error specified below , if i change this to refer each attribute value independently i see the chart is getting installed , pod deploys successfully.
livenessProbe:
- {{ .Values.monitorConfig.liveness }}
readinessProbe:
- {{ .Values.monitorConfig.readiness }}
Can anyone please let me know what can be done to avoid the error and why??
Thank you.
Helm Command
helm install --debug -n pspk ./pkg/helm/my-service/
Error
Error: release pspk failed: Deployment in version "v1beta1" cannot be
handled as a Deployment: v1beta1.Deployment.Spec:
v1beta1.DeploymentSpec.Template: v1.PodTemplateSpec.Spec:
v1.PodSpec.Containers: []v1.Container: v1.Container.LivenessProbe:
readObjectStart: expect { or n, but found [, error found in #10 byte
of ...|ssProbe":["map[failu|..., bigger context
...|"imagePullPolicy":"IfNotPresent","livenessProbe":["map[failureThreshold:3
httpGet:map[path:/greeting|...
deployment.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: {{ template "fullname" . }}
labels:
app: {{ template "fullname" .}}
chart: "{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}"
release: "{{ .Release.Name }}"
spec:
replicas: {{ .Values.replicaCount }}
template:
metadata:
labels:
app: {{ template "fullname" . }}
spec:
containers:
- name: {{ .Chart.Name }}
image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
imagePullPolicy: {{ .Values.image.pullPolicy }}
ports:
- name: http
containerPort: 50443
protocol: TCP
- name: grpc
containerPort: 50051
protocol: TCP
livenessProbe:
- {{ .Values.monitorConfig.liveness }}
readinessProbe:
- {{ .Values.monitorConfig.readiness }}
resources:
{{ toYaml .Values.resources | indent 12 }}
values.yaml
replicaCount: 2
application:
track: stable
image:
repository: test/go-k8s
tag: 0.1.1
pullPolicy: IfNotPresent
# SQL migration scripts
service:
enabled: false
type: NodePort
port: 80
grpc_port: 50051
env:
# POSTGRES_HOST
postgresHost: localhost
# POSTGRES_PORT
postgresPort: "5432"
# POSTGRES_SSL_MODE
postgresSSLMode: "disable"
# POSTGRES_DB
postgresDB: test
# POSTGRES_USER
postgresUser: test
# POSTGRES_PASSWORD
postgresPassword: "test"
monitorConfig:
liveness:
httpGet:
path: "/greeting"
port: 50443
periodSeconds: 2
timeoutSeconds: 10
initialDelaySeconds: 5
failureThreshold: 3
successThreshold: 1
readiness:
httpGet:
path: "/greeting"
port: 50443
periodSeconds: 2
timeoutSeconds: 10
initialDelaySeconds: 5
failureThreshold: 3
successThreshold: 1
resources: {}
nodeSelector: {}
tolerations: []
affinity: {}

Answer 1

You need to do two things to make this work correctly: explicitly serialize the value as YAML, and make the indentation correct. This tends to look something like
livenessProbe:
- {{ .Values.monitorConfig.liveness | toYaml | indent 8 | trim }}
The default serialization will be a Go-native dump format, which isn't YAML and leads to the weird map[failureThreshold:1] output; toYaml fixes this. indent 8 puts spaces at the front of every line in the resulting block (you will need to adjust the "8"). trim removes leading and trailing spaces. (toYaml is Helm-specific and isn't documented well; the other two functions come from the Sprig support library.)
You should double-check this output with
helm template -n pspk ./pkg/helm/my-service/
and if it doesn't look like valid YAML, adjust it further.

Answer 2

In your YAML:
livenessProbe:
- {{ .Values.monitorConfig.liveness }}
readinessProbe:
- {{ .Values.monitorConfig.readiness }}
You insert your values into sequence items. Sequence items in YAML are started with -. However, the contents of livenessProbe is expected to be a YAML mapping. The error message is poor but tells you what goes wrong:
expect { or n, but found [,
{ starts a YAML mapping (in flow style), [ starts a YAML sequence (in flow style). The message tells you that the start of a YAML mapping is expected, but the start of a YAML sequence is found. Note that since you're using block style, you don't actually use { and [ here.
So to fix it, simply remove the - so that your inserted mapping (as seen in your values.yaml) is the direct value of livenessProbe and not contained in a sequence:
livenessProbe:
{{ .Values.monitorConfig.liveness }}
readinessProbe:
{{ .Values.monitorConfig.readiness }}

Answer 3

Thanks to the community answers/comments and helm template guide,
it can be combined into:
{{- if .Values.monitorConfig.liveness }}
livenessProbe:
{{ toYaml .Values.monitorConfig.liveness | indent 12 }}
{{- end }}
This will give more flexibility.