Read variable inside double bracket in Helm template - kubernetes-helm

I need read a field file from values.yml for a configMap setup, it's my template:
{{- if .Values.configMap.enabled }}
{{- range .Values.configMapMount }}
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ .name }}
data:
{{ .file }}: {{ $.Files.Get "files/{{ .file }}" | printf "%s" | indent 4 }}
{{- end }}
{{- end }}
Obviously this template doesn't work...there is a way to read {{ .file }} inside "files/{{ .file }}" ?
Thanks


You can't nest template actions. Use a variable instead.
Something like this:
{{- if .Values.configMap.enabled }}
{{- range .Values.configMapMount }}
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ .name }}
data:
{{- $f := printf "files/%s" .file }}
{{ .file }}: {{ $.Files.Get $f | printf "%s" | indent 4 }}
{{- end }}
{{- end }}
https://go.dev/play/p/pRd5WNc10Zt

Related

Expand helm template variables to lookup named-template/sub-template in _helpers.tpl

Trying to do the following in helm template but it's not expanding $key and giving an error cannot find template $key .
Is this even possible?
values.yaml
app:
env:
- AAAA
_helpers.tpl
{{- define "AAAA" }}
{{- printf "BBBB" }}
{{- end }}
deployment.yaml
...
container:
- name: xxxx
env:
{{- range $key := .Values.app.env }}
- name: {{ $key }}
value: {{ template "$key" . }}
{{ end }}

looks like using include instead of template works
values.yaml
app:
env:
- AAAA
_helpers.tpl
{{- define "AAAA" }}
{{- printf "BBBB" }}
{{- end }}
deployment.yaml
...
container:
- name: xxxx
env:
{{- range $key := .Values.app.env }}
- name: {{ $key }}
value: {{ include $key . }}
{{ end }}

Helm Chart. How to pass a env value with multiple dots?

In deployment.yaml contains the condition:
{{- if or $.Values.env $.Values.envSecrets }}
env:
{{- range $key, $value := $.Values.env }}
- name: {{ $key }}
value: {{ $value | quote }}
{{- end }}
{{- range $key, $secret := $.Values.envSecrets }}
- name: {{ $key }}
valueFrom:
secretKeyRef:
name: {{ $secret }}
key: {{ $key | quote }}
{{- end }}
{{- end }}
If I pass the $key = helm install NAME nexus/stand --set env.server.servlet.context-path=/bpm/router-app, then i don't get what i expect:
Containers:
...
Environment:
server: map[servlet:map[context-path:/bpm/router-app]]
How can I get around this problem and get the environment like:
Environment:
server.servlet.context-path: /bpm/router-app

Use double backslashes.
helm install NAME nexus/stand --set env.server\\.servlet\\.context-path=/bpm/router-app
That is the equivalent of:
env:
server.servlet.context-path: /bpm/router-app
This is useful particularly for annotations.
Alternatively you should be able to use quotes and single backslashes.
helm install NAME nexus/stand --set 'env.server\.servlet\.context-path'=/bpm/router-app

helm template check for empty string

I have been asked to modify a Helm template to accommodate a few changes to check if a value is empty or not as in the code snippet below. I need to check $var.alias inside the printf in the code snippet and write custom logic to print a custom value. Any pointers around the same would be great.
{{- range $key, $value := .Values.testsConfig.keyVaults -}}
{{- range $secret, $var := $value.secrets -}}
{{- if nil $var.alias}}
{{- end -}}
{{ $args = append $args (printf "%s=/mnt/secrets/%s/%s" $var.alias $key $var.name | quote) }}
{{- end -}}
{{- end -}}

I decided to test what madniel wrote in his comment. Here are my files:
values.yaml
someString: abcdef
emptyString: ""
# nilString:
templates/test.yaml
{{ printf "someEmptyString=%q)" .Values.someString }}
{{ printf "emptyString=%q)" .Values.emptyString }}
{{ printf "nilString=%q)" .Values.nilString }}
{{- if .Values.someString }}
{{ printf "someString evaluates to true" }}
{{- end -}}
{{- if .Values.emptyString }}
{{ printf "emptyString evaluates to true" }}
{{- end -}}
{{- if .Values.nilString }}
{{ printf "nilString evaluates to true" }}
{{- end -}}
{{- if not .Values.emptyString }}
{{ printf "not emptyString evaluates to true" }}
{{- end -}}
{{- if not .Values.nilString }}
{{ printf "not nilString evaluates to true" }}
{{- end -}}
Helm template output:
➜ helm template . --debug
install.go:173: [debug] Original chart version: ""
install.go:190: [debug] CHART PATH: <REDACTED>
---
# Source: asd/templates/test.yaml
someEmptyString="abcdef")
emptyString="")
nilString=%!q(<nil>))
someString evaluates to true
not emptyString evaluates to true
not nilString evaluates to true
So yes, it should work if you use {{ if $var.alias }}

How to generate a Consul template inside a Helm Chart

I have a Helm Chart for a Spring Boot application that gets its database credentials injected by the Hashicorp Vault agent injector.
This is a snippet from the generated deployment manifest in the dev environment.
annotations:
vault.hashicorp.com/agent-inject: "true"
vault.hashicorp.com/role: "app"
vault.hashicorp.com/agent-inject-secret-database.properties: "secret/data/app/dev/database"
vault.hashicorp.com/agent-inject-template-database.properties: |
{{ with secret "secret/data/app/dev/database" }}
spring.datasource.username: {{ .Data.data.username }}
spring.datasource.password: {{ .Data.data.password }}
{{ end }}
To be able to specify the path to the secret and the name of the generated secrets file in the values.yaml, I've constructed this template:
annotations:
vault.hashicorp.com/agent-inject: "true"
vault.hashicorp.com/role: "{{ .Values.vault.role }}"
{{ print "vault.hashicorp.com/agent-inject-secret-" .Values.vault.secretFileName }}: "{{ .Values.vault.secretPath }}"
{{ print "vault.hashicorp.com/agent-inject-template-" .Values.vault.secretFileName }}: |
{{`
{{ with secret "`}} {{- .Values.vault.secretPath -}} {{`" }}
spring.datasource.username: {{ .Data.data.username }}
spring.datasource.password: {{ .Data.data.password }}
{{ end }}
`}}
It works as intended, but I don't think it's very elegant.
I've also tried this approach:
annotations:
vault.hashicorp.com/agent-inject: "true"
vault.hashicorp.com/role: "{{ .Values.vault.role }}"
{{ print "vault.hashicorp.com/agent-inject-secret-" .Values.vault.secretFileName }}: "{{ .Values.vault.secretPath }}"
{{ print "vault.hashicorp.com/agent-inject-template-" .Values.vault.secretFileName }}: |
{{ print "{{ with secret " .Values.vault.secretPath " }}" }}
{{ print "spring.datasource.username: {{ .Data.data.username }}" }}
{{ print "spring.datasource.password: {{ .Data.data.password }}" }}
{{ print "{{ end }}" }}
Which I feel is slightly better, but I'm still not happy with it.
So my question is: Is there a better way to do it?

I am using this way in my helm Chart
annotations:
vault.hashicorp.com/agent-inject: true
vault.hashicorp.com/role: {{ $.Values.injector.role }}
vault.hashicorp.com/agent-inject-secret-app: kv/k8s-{{ $.Values.environment }}/{{ $.Values.APP_NAME }}
vault.hashicorp.com/agent-inject-template-app: |
{{`{{ with secret "`}} kv/k8s-{{- $.Values.environment -}}/{{ $.Values.APP_NAME }} {{`" }}
{{ range $key, $value := .Data }}
export {{ $key }}={{ $value }}
{{ end }}`}}

helm double quote annotations value

I am trying to quote my annotation values. I am trying like this
annotations:
{{- range $key, $value := .Values.ingress.annotations }}
{{ $key }}: {{ printf "%s" $value | quote }}
{{- end }}
and this
annotations:
{{- range $key, $value := .Values.ingress.annotations }}
{{ $key }}: "{{ $value }}"
{{- end }}
this is my values.yaml
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/force-ssl-redirect: false
but it is not working. Even if I double quote the annotation value in values.yaml helm is removing the quote. Can somebody tell me how can I get helm with double quote values in annotation?
I am using Helm version 3.

You could try this:
annotations:
{{- range $key, $value := .Values.ingress.annotations }}
{{ $key }}: {{ $value | quote }}
{{- end }}