Helm template is not compatible to values.yaml structure - kubernetes-helm

Question

I have the following ingress.yaml:
spec:
{{- if .Values.ingress.tls }}
tls:
{{- range .Values.ingress.tls }}
- hosts:
{{- range .hosts }}
- {{ . | quote }}
{{- end }}
secretName: {{ .secretName }}
{{- end }}
{{- end }}
rules:
{{- range .Values.ingress.hosts }}
- host: {{ .host }} // row 31
http:
paths:
{{- range .paths }}
- path: {{ . | quote }}
backend:
serviceName: {{ $fullName }}
servicePort: {{ $svcPort }}
{{- end }}
{{- end }}
{{- end }}
And the following values to feed this template:
hosts:
host: "app.example.com"
paths:
- "/api"
- "/oauth"
tls:
- secretName: "example-tls"
hosts:
- "*.app.example.com"
- "dev.example.com"
When I run "helm install" it fails on:
Error: UPGRADE FAILED: template: templates/ingress.yaml:31:15:
executing "templates/ingress.yaml" at <.host>: can't evaluate field
host in type interface {}
So for me it looks like hosts must be a list, not a dictionary (because of range instruction). So I convert it:
hosts:
- host: "app.example.com"
paths:
- "/api"
- "/oauth"
But in this case I get:
warning: destination for hosts is a table. Ignoring non-table value
[map[host:app.example.com paths:[/api /oauth]]]
and the same error as above in addition.
How to make it working?
UPDATE 1
Values:
ingress:
enabled: true
rules:
- host: c1.app.example.com
paths:
- /api
- /oauth
- host: c2.app.example.com
paths:
- /api
- /oauth
tls:
- secretName: "example-tls"
hosts:
- "*.app.example.com"
- "dev.example.com"
Template:
{{- if .Values.ingress.tls }}
tls:
{{- range .Values.ingress.tls }}
- hosts:
{{- range .hosts }}
- {{ . | quote }}
{{- end }}
secretName: {{ .secretName }}
{{- end }}
{{- end }}
rules:
{{- range .Values.ingress.rules }}
- host: {{ .host | quote }}
http:
paths:
{{- range .paths }}
- path: {{ . | quote }}
backend:
serviceName: {{ $fullName }}
servicePort: {{ $svcPort }}
{{- end }}
{{- end }}
{{- end }}
UPDATE 2
I understood that problem was not in code but in command line. I fed with string instead of array.
helm template ... --set ingress.hosts.host=c1.app.example.com ...
I will try to figure out how to provide multiple values and update it here.
UPDATE 3
I erased data from values:
ingress:
enabled: false
rules:
- host:
tls:
- secretName:
hosts: []

Answer 1

The template is looking for .Values.ingress.hosts, whereas in your displayed values there is no ingress prefix. And as range operator is being used, we should have a list of dictionary.
Also, before doing a helm install, it would be good to run helm template just to make sure the the YAML definitions are rendered correctly.
Considering the below content in values.yaml:
---
ingress:
hosts:
-
host: app1.example.com
paths:
- /api
- /oauth
-
host: app2.example.com
paths:
- /api1
- /authz
tls:
- hosts:
- "*.app.example.com"
- "dev.example.com"
secretName: "example-tls"
Running helm template command results in (I have defined serviceName as haproxy, and servicePort as 8080 for illustration):
spec:
tls:
- hosts:
- "*.app.example.com"
- "dev.example.com"
secretName: example-tls
rules:
- host: app1.example.com // row 31
http:
paths:
- path: "/api"
backend:
serviceName: haproxy
servicePort: 8080
- path: "/oauth"
backend:
serviceName: haproxy
servicePort: 8080
- host: app2.example.com // row 31
# similar output for app2.example.com

Answer 2

Answering my own question.
The problem was in mismatch of ingress template structure and command line arguments that I have provided for params override.
This is the proper fit of command line arguments:
helm upgrade <some other options here>
--values ./values.yaml
--set ingress.enabled=True
--set ingress.tls[0].hosts[0]=app.example.com
--set ingress.tls[0].secretName=example-tls
--set ingress.rules[0].host=app.example.com
That populates values.yaml:
ingress:
enabled: false
rules:
- host:
tls:
- secretName:
hosts: []
For ingress template:
spec:
{{- if .Values.ingress.tls }}
tls:
{{- range .Values.ingress.tls }}
- secretName: {{ .secretName }}
hosts:
{{- range .hosts }}
- {{ . | quote }}
{{- end }}
{{- end }}
{{- end }}
rules:
{{- range .Values.ingress.rules }}
- host: {{ .host | quote }}
http:
paths:
- path: /api
backend:
serviceName: {{ $fullName }}
servicePort: {{ $svcPort }}
{{- end }}
{{- end }}