Grafana braces {{ }} collide with my Helm chart braces {{ }}.
Is it possible to change braces in Grafana from {{ }} to {% %}?
Is it possible to change braces in Helm from {{ }} to {% %}?
Unfortunately, the most straightforward way to do this is to provide the Grafana template data as a raw string in the Helm template, something like this:
apiVersion: v1
kind: ConfigMap
name: stackoverflow-example
data:
grafana.template: |-
{{`{{ your-grafana.data.here }}`}}
In this case, the Helm template will only see the outer pair, and render the rest as an opaque string.
Related
Struggling with some helm templating...
I'm trying to pass a separate yaml file with springboot parameters to helm, and have them split by environment... then I want to pass the environment to helm using --set env=staging
Feels like I've tried everything but clearly I'm lacking a fundamental understanding...
My _helpers.tpl contains these:
{{- define "env" }}
{{- printf "%s" .Values.env }}
{{- end }}
{{ define "configmap.metadata" }}
name: {{ .Values.name }}-config
{{ end }}
{{ define "configmap.properties" }}
{{ index .Values.environment (include "env" .) "properties" | indent 4 }}
{{ end }}
The template for the config map:
apiVersion: v1
kind: ConfigMap
metadata:
{{ include "configmap.metadata" . }}
data:
app.properties: |-
{{ include "configmap.properties" .}}
And the yaml file containing the properties looks like this:
environment:
staging:
properties:
spring:
datasource:
url: something
username: something
password: something
app1:
key: something
secret: something
baseUri: something
app2:
bootstrap_server: something
bootstrap_port: something
registry_schema: something
production:
properties:
spring:
etc, etc
And then I want to select the environment using set. I'm testing with:
helm template test . -f values.yaml -f properties.yaml --set env=staging
I think I've just tried so many things that I just can't see the wood for the trees! The error I'm seeing is:
Error: template: microservice/templates/configmap.yaml:7:7: executing "microservice/templates/configmap.yaml" at <include "configmap.properties" .>: error calling include: template: microservice/templates/_helpers.tpl:56:76: executing "configmap.properties" at <4>: wrong type for value; expected string; got map[string]interface {}
EDIT:
After tweaking, I'm still getting an error, but I'm seeing something in the configmap.. but I wonder if the error is due to the 8 spaces on the first line..
data:
app.properties: |-
app2:
bootstrap_port: something
bootstrap_server: something
registry_schema: something
app1:
baseUri: something
key: something
secret: something
spring:
datasource:
password: something
url: something
username: something
I think your actual error message is around the way you're using the .Values.environment.production.properties value. It's a YAML map, but the indent function expects it to be a string. You should be able to see some odd indentation and maybe an odd [map spring [map datasource ...]] string if you use the helm template --debug option.
When you go to render the ConfigMap, you need to make sure to do two things. Since the data you have is structured properties, you need to use the lightly-documented toYaml function to convert it back to YAML. This will begin at the first column, so you need to apply the indent function to it, and then you need to make sure the markup that invokes it is also at the first column (indent should be the only thing that supplies indentation).
data:
app.properties: |-
{{ include "configmap.properties" . | indent 4}}
{{/*- starts at column 1, but includes the `indent` function */}}
{{ define "configmap.properties" }}
{{- index .Values.environment (.Values.env) "properties" | toYaml }}
{{/*- starts at first column, includes `toYaml`, does not include `indent` */}}
{{- end }}
I'm using a chart it's using other chart as dependency.
Its chart.yaml file is:
annotations:
category: Infrastructure
apiVersion: v2
appVersion: 3.7.0
dependencies:
- name: common
repository: https://charts.bitnami.com/bitnami
tags:
- bitnami-common
version: 1.x.x
...
It's using this dependecy into its templates like:
apiVersion: v1
kind: Service
metadata:
...
labels: {{- include "common.labels.standard" . | nindent 4 }}
app.kubernetes.io/component: zookeeper
{{- if .Values.commonLabels }}
{{- include "common.tplvalues.render" ( dict "value" .Values.commonLabels "context" $ ) | nindent 4 }}
{{- end }}
...
As you can see it's using:
labels: {{- include "common.labels.standard" . | nindent 4 }}
How can I override those values inherited from common.
The Bitnami Common Library Chart is a library chart: it doesn't provide any Kubernetes resources of its own, just a library of template functions you can call (with include or template). That also means it doesn't have its own set of values in the way Helm dependency charts normally do; it uses whatever .Values are in the object you pass to the template.
The implementation of common.labels.standard is pretty straightforward; it provides a set of standard labels that almost every chart should have. You don't usually need to edit these, and you can't change their outputs without copying and pasting the template contents.
Note that one consequence of this is that, if you have a parent chart and a subchart that both include "common.labels.standard" ., they will get different values. .Release.Name will be the same for both, but .Chart.Name will depend on the specific chart being installed (parent or dependency), and in the subchart, .Values will be narrowed to that subchart's settings in the top-level values.
If you need to add labels, this change is easy, and you demonstrate it above. Helm's general operation is to run the template engine naïvely to produce a text document, then hope it's a valid YAML file. If you want additional labels, just include them in the template.
metadata:
labels:
{{-/* the generated labels from the Common chart */}}
{{- include "common.labels.standard" . | indent 4 }}
{{-/* and then any additional labels (correctly indented) */}}
example.com/additional-label: is-present
currently we're adding features to 3rd party helm charts we're deploying (for example - in prometheus we're adding an authentication support as we use nginx ingress controller).
Obviously, this will cause us headaches when we want to upgrade those helm charts, we will need to perform "diffs" with our changes.
What's the recommended way to add functionality to existing 3rd party helm charts? Should i use umbrella charts and use prometheus as a dependency? then import value from the chart? (https://github.com/helm/helm/blob/master/docs/charts.md#importing-child-values-via-requirementsyaml)
Or any other recommended way?
-- EDIT --
Example - as you can see, i've added 3 nginx.ingress.* annotations to support basic auth on prometheus ingress resource - of course if i'll upgrade, i'll need to manually add them again, which will cause problems
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
{{- if .Values.prometheus.ingress.annotations }}
annotations:
{{ toYaml .Values.prometheus.ingress.annotations | indent 4 }}
{{- end }}
{{- if .Values.alertmanager.ingress.nginxBasicAuthEnabled }}
nginx.ingress.kubernetes.io/auth-realm: "Authentication Required - ok"
nginx.ingress.kubernetes.io/auth-secret: {{ template "prometheus-operator.fullname" . }}-prometheus-basicauth
nginx.ingress.kubernetes.io/auth-type: "basic"
{{- end }}
name: {{ $serviceName }}
labels:
app: {{ template "prometheus-operator.name" . }}-prometheus
{{ include "prometheus-operator.labels" . | indent 4 }}
{{- if .Values.prometheus.ingress.labels }}
{{ toYaml .Values.prometheus.ingress.labels | indent 4 }}
{{- end }}
spec:
rules:
{{- range $host := .Values.prometheus.ingress.hosts }}
- host: {{ . }}
http:
paths:
- path: "{{ $routePrefix }}"
backend:
serviceName: {{ $serviceName }}
servicePort: 9090
{{- end }}
{{- if .Values.prometheus.ingress.tls }}
tls:
{{ toYaml .Values.prometheus.ingress.tls | indent 4 }}
{{- end }}
{{- end }}
I think that might answer your question.
Subcharts and Globals
Requirements
Helm Dependencies
This led me to find the specific part I was looking for, where the parent chart can override sub-charts by specifying the chart name as a key in the parent values.yaml.
In the application chart's requirements.yaml:
dependencies:
- name: jenkins
# Can be found with "helm search jenkins"
version: '0.18.0'
# This is the binaries repository, as documented in the GitHub repo
repository: 'https://kubernetes-charts.storage.googleapis.com/'
Run:
helm dependency update
In the application chart's values.yaml:
# ...other normal config values
# Name matches the sub-chart
jenkins:
# This will be override "someJenkinsConfig" in the "jenkins" sub-chart
someJenkinsConfig: value
I would either fork and handle integrating the changes when you upgrade/rebase, or if possible disable the ingress elements for those you want to customise via the values.yaml file. Then create your own ingress instances manually with the customisations you need in another custom chart, and provide it the references it needs from the prometheus chart as normal values.yaml inputs.
Obviously this approach has it's limitations, if the customisations are too tightly coupled to the chart it might not be possible to split them out.
Hope this helps.
I have a Helm chart that I am deploying to Azure Kubernetes Service, and minikube for development purposes.
When deploying to minikube, I need to add a secret so the cluster can speak with my Azure Container Registry. This is not necessary when I'm deploying to AKS.
Is there any way I can specify whether or not to include the secret through a --set value with helm install, or do I have to set up different helm charts?
You can put anything you want inside a Go text/template conditional block, even whole Kubernetes resources.
# templates/some-secret.yaml
{{ if .Values.theSecret }}
apiVersion: v1
kind: Secret
metadata:
name: {{ template "some.name" . }}-some-secret
labels:
{{ template "some.labels" . | indent 4 }}
data:
theSecret: {{ .Values.theSecret | b64enc }}
{{ end }}
Or, if you already have some shared Secret, you can make individual values conditional
data:
someValue: {{ .Values.someValue | b64enc }}
{{- if .Values.theSecret }}
theSecret: {{ .Values.theSecret | b64enc }}
{{- end }}
As the chart author you need to write this into the chart. If you're using a third-party chart, it's up to the chart author to provide this functionality.
I'm starting to write helm charts for our services.
There are two things I'm not sure how they are supposed to work or what to do with them.
First: the release name. When installing a chart, you specify a name which helm uses to create a release. This release name is often referenced within a chart to properly isolate chart installs from each other? For example the postgres chart contains:
{{- define "postgresql.fullname" -}}
{{- $name := default .Chart.Name .Values.nameOverride -}}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" -}}
{{- end -}}
Which is then used for the service:
metadata:
name: {{ template "postgresql.fullname" . }}
It does look like "myrelease-postgresql" in the end in kubernetes.
I wonder what a good release name is? What is typically used for this? A version? Or some code-name like the ubuntu releases?
Second: referencing values.
My chart uses postgresql as a sub-chart. I'd like to not duplicate the way the value for the name of the postgresql service is created (see snipped above).
Is there a way I can reference the service name of a sub-chart or that template define {{ template "postgresql.fullname" . }} in the parent chart? I need it to pass it into my service as database host (which works if I hardcode everything but that cannot be the meaning of this).
I tried:
env:
- name: DB_HOST
value: {{ template "mychart.postgresql.fullname" . }}
But that lead into an error message:
template "mychart.postgresql.fullname" not defined
I've seen examples of Charts doing similar things, like the odoo chart. But in here that logic how the postgresql host name is created is copied and an own define in the template is created.
So is there a way to access sub-chart names? Or values or template defines?
Thanks!
Update after some digging:
According to Subcharts and Globals the templates are shared between charts.
So what I can do is this:
In my chart in _helpers.tpl I add (overwrite) the postgres block:
{{- define "postgresql.fullname" -}}
{{- $name := .Values.global.name -}}
{{- printf "%s-%s" $name "postgresql" | trunc 63 | trimSuffix "-" -}}
{{- end -}}
So this value is used when the sub-chart is deployed. I cannot reference all values or the chart name in here as it will be different in the sub-chart - so I used a global value.
Like this I know the value of the service that is created in the sub-chart.
Not sure if this is the best way to do this :-/
Are you pulling in postgresql as a subchart of your chart (via your chart's requirements.yaml)? If so, both the postgresql (sub) chart and your chart will have the same .Release.Name - thus, you could specify your container's environment as
env:
- name: DB_HOST
value: {{ printf "%s-postgresql" .Release.Name }}
if you override postgresql's name by adding the following to your chart's values.yaml:
postgresql:
nameOverride: your-postgresql
then your container's env would be:
env:
- name: DB_HOST
value: {{ printf "%s-%s" .Release.Name .Values.postgresql.nameOverride }}
You can overwrite the values of the subchart with the values of the parent chart as described here:
https://helm.sh/docs/chart_template_guide/subcharts_and_globals/
I don't think it's possible (and it also doesn't make sense) to override the template name of the subchart.
What I would do is define the database service name in the .Values files both in the parent and sub charts and let helm override the one in the subchart - that way you will always have the database name in the parent chart. This would however mean that the service name of the database should not be {{ template "name" . }}, but something like {{ .Values.database.service.name }}
mychart/.Values
mysubchart:
service:
name: my-database
mychart/templates/deployment.yaml
env:
- name: DB_HOST
value: {{ .Values.mysubchart.service.name }}
mychart/charts/mysubchart/.Values
service:
name: my-database
mychart/charts/mysubchart/templates/service.yaml:
apiVersion: v1
kind: Service
metadata:
name: {{ .Values.service.name }}
Another way is to use global chart values, also described in https://helm.sh/docs/chart_template_guide/subcharts_and_globals/
For values in the helper.tpl instead of values.yaml
To access a value from a chart you do the following:
{{ template "keycloak.fullname" . }}
To access a value from a sub chart
{{ template "keycloak.fullname" .Subcharts.keycloak }}
You could import values from a sub chart as described here: https://helm.sh/docs/topics/charts/#importing-child-values-via-dependencies.
However there is a caveat. This works not for values defined at the root level in the values.yaml.
See this issue for more information: https://github.com/helm/helm/issues/9817