Whats the best way to get the helm subchart service names to reference into my ingress controller that will sit in the parent chart
values.yaml
---
ingress:
paths:
- serviceName: app-1
path: /app-1/*
port: 8080
- serviceName: app-2
path: /app-2/*
port: 8080
ingress.yaml
---
{{- range .Values.ingress.paths }}
- path: {{ .path }}
backend:
{{- $subchart := .serviceName -}}
serviceName: {{- include "$subchart.fullname" .}}
servicePort: {{ .port }}
{{- end }}
template: no template "$subchart.fullname" associated with template "gotpl"
helm 3.7 version has solved the problem
https://github.com/helm/helm/pull/9957.
You can use like this
{{ template "bar.fullname" .Subcharts.bar }}
How about hardcoded subchart name scoped by release ?
{{ .Release.Name }}-<subchart_name>
I have found that the best way to reference a service name is to override the template that they are using. There are some caveats to doing this however.
The subchart and your chart will have different contexts so they will most likely render the template differently
There are some things that are only available to the subchart
Most charts have a template similar to the one below in their _helpers.tpl file.
{{/*
Create a default fully qualified app name.
We truncate at 63 chars because some Kubernetes name fields are limited to this (by the DNS naming spec).
If release name contains chart name it will be used as a full name.
*/}}
{{- define "newchart.fullname" -}}
{{- if .Values.fullnameOverride }}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- $name := default .Chart.Name .Values.nameOverride }}
{{- if contains $name .Release.Name }}
{{- .Release.Name | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
{{- end }}
{{- end }}
{{- end }}
The subchart has different .Values to your chart. We will fix this when we render this template by creating a context that is similar to the subcharts context.
Instead of calling it with the . context we create a new context by replacing the .Values with the subcharts .Values.
{{ template "newchart.fullname" (set (deepCopy .) "Values" .Values.newchart }}
We use deepCopy so that we don't actually change the . context but rather create a new one to use.
The subchart has access to its own .Chart values that we can't replicate. In this case we will have to hardcode the value of .Chart.Name to the template. In this we can just replace it with the chart name newchart.
Once we have done this both nameOverride and fullnameOverride on the subchart will work without you having to manually change anything in your template files.
If the subchart uses the fullname function from _helpers.tpl (provided by helm by default for new charts) you can use this (replace postgresql with the name of the subchart):
{{- $fullName := include "postgresql.fullname" (mustMerge (dict "Chart" (dict "Name" "postgresql") "Values" .Values.postgresql) (deepCopy .)) -}}
It depends on the sub-chart definition!
As an example, elasticsearch chart, see here https://github.com/elastic/helm-charts/blob/master/elasticsearch/templates/service.yaml, is defining 2 services.
Both services name can be declared as value clusterName.
Related
I’m trying to defines some variables in order to make my helm chart non-repeatable
I created a helpers file which contains the following section:
{{ $config := .Values.service }}
{{- range .Values.services }}
{{ $config.$serviceName }}
{{- define "{{ $serviceName }}.selectorLabels" -}}
app.kubernetes.io/name: {{ .name }}
app.kubernetes.io/instance: {{ .instance }}
{{- end -}}
{{- end -}}
values.yaml:
services:
- service1
- service2
- service3
service:
- service1:
name: service1
- service2:
name: service2
- service3:
name: service3
but it keeps prompting an error for bad character U+0024 ‘$’
Do you know how can I define a variable by other variable?
Neither the Go text/template language, the Sprig extensions, nor Helm's local extensions have a way to define a template with a dynamic name. The name in a define call must be a fixed string. The text/template documentation notes (under "Nested template definitions"):
Template definitions must appear at the top level of the template.... The define action names the template being created by providing a string constant.
However, templates take a (single) parameter. Instead of trying to define a separate template for each dynamically-specified value, you could define a single template that produces this content, and then call it with the dynamic settings.
{{- define "selectorLabels" -}}{{/* <-- fixed name */-}}
{{/* .name is relative to the template parameter . */-}}
app.kubernetes.io/name: {{ .name }}
app.kubernetes.io/instance: {{ .instance }}
{{- end -}}
{{- range .Values.services }}
{{-/* . is one item from the services list */}}
{{ include "selectorLabels" . }}
{{- end -}}
You may find a simpler Helm values structure easier to work with as well. If you decompose .Values.service, it is a list, where each list is a single-item dictionary, where the key comes from a separate list. You might structure this as a single flat list of settings dictionaries, embedding the item name as a name: value within the structure (like for example the containers: list in a pod spec).
services:
- name: service1
instance: foo
- name: service2
instance: bar
- name: service3
instance: baz
I'm using Helm for to deploy multiple K8s deployments. In some deployments I need to include extra environment variables, but for the majority of deployment the standard env. variables are enough. I would like to have named template for those deployments that must have extra env. variables.
Can I include a named template only if the named template exist?
Something like this:
{{ range $idx, $svc := .Values.services }}
kind: Deployment
metadata:
name: {{ $svc.name }}
spec:
containers:
- name: {{ $svc.name }}
env:
- name: JAVA_OPTS
- value: {{ $svc.javaOpts }}
# if template_exists (print $svc.name "-env")
{{ include (print $svc.name "-env") . | indent 12 }}
# end
{{- end -}}
It's in pseudo-code. How to do the # if part?
Thank you.
The easiest way would be to add additional key like templateExists: true to your services and check it with a simple if statement in your deployment:
{{- if $svc.templateExists }}
{{ include (print $svc.name "-env") . | indent 8 }}
{{- end -}}
services:
svc1:
templateExists: true
name: svc1
javaOpts: "-Xms128m -Xmx512m"
svc2:
name: svc2
javaOpts: "-Xms256m -Xmx512m"
Here is a solution that I came up now. I check if there are any files in the chart that matches the pattern [service]-env.yaml and if there are then I include the content of that file in the deployment.
{{- range $path, $_ := $f.Glob "**-env.yaml" }}
{{- if contains $svc.app.name $path }}
{{ $f.Get $path | indent 8 }}
{{- end }}
{{- end }}
That way, for services that require extra env. variables we can include a file in files/service-env.yaml and those variables will be added to the deployment. For services that do not require such variables, it's left empty.
I could find both fullnameOverride and nameOverride in Helm chart.Please help clarifying what is the difference between these two with an example.
nameOverride replaces the name of the chart in the Chart.yaml file, when this is used to construct Kubernetes object names. fullnameOverride completely replaces the generated name.
These come from the template provided by Helm for new charts. A typical object in the templates is named
name: {{ include "<CHARTNAME>.fullname" . }}
If you install a chart with a deployment with this name, and where the Chart.yaml file specifies name: chart-name...
helm install release-name ., the Deployment will be named release-name-chart-name
helm install release-name . --set nameOverride=name-override, the Deployment will be named release-name-name-override
helm install release-name . --set fullnameOverride=fullname-override, the Deployment will be named fullname-override
The generated ...fullname template is (one code branch omitted, still from the above link)
{{- define "<CHARTNAME>.fullname" -}}
{{- if .Values.fullnameOverride }}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- $name := default .Chart.Name .Values.nameOverride }}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
{{- end }}
{{- end }}
So if fullnameOverride is provided, that completely replaces the rest of the logic in the template. Otherwise the name is constructed from the release name and the chart name, where nameOverride overrides the chart name.
I’ve created helm chart which is working as expected, however I want to change the names of the deployed
application
currently for each deployment I got different (random) name and I want it to be a fixed name, how can I do that?
This is the helper
{{/* vim: set filetype=mustache: */}}
{{/*
Expand the name of the chart.
*/}}
{{- define "unleash.name" -}}
{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" -}}
{{- end -}}
{{/*
Create a default fully qualified app name.
We truncate at 63 chars because some K8S name fields are limited to this (by the DNS naming spec).
*/}}
{{- define "unleash.fullname" -}}
{{- $name := default .Chart.Name .Values.nameOverride -}}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" -}}
{{- end -}}
This is the outcome of the name after deployment
crabby-ibex-postgresql-0 0/1 Pending 0 1s
crabby-ibex-unleash-86775cdffd-xt575 0/1 ContainerCreating 0 1s
This is the names from the values yaml
replicaCount: 1
namespace: unleash
restartPolicy: Never
name: a-unleash
nameOverride: unleash
e.g. I want it instead of
crabby-ibex-unleash-86775cdffd-xt575
to be like
unleash-service
uleash-postgressql
update
I've added the following to the _helper.tpl
{{- if .Values.fullnameOverride -}}
{{- .Values.fullnameOverride | trunc 26 | trimSuffix "-" -}}
{{- end -}}
and put the following in the values.yml
fullnameOverride: apps
i expect that the artifacts will start with apps and it doesnt work
I don't know, why nobody posted it yet. You can pass the name of the Helm release to the helm install command:
helm install <your_Chart.yaml_directory> -n <release_name>
Based of name crabby-ibex-unleash-86775cdffd-xt575 I guess you are using kind: Deployment for this application, if you change kind to StatefulSet in you yaml you will end up with pod named uleash-postgressql-0, but because of helm you have additional prefix, you could use --name=you_relese_name which will create pod you_relese_name-uleash-postgressql-0.
If you really want to get rid of helm chart prefix you have to set fullnameOverride for every chart you are deploying.
EDIT:
To make use of fullnameOverride you have to define it in your _helpers.tpl file.
{{/* vim: set filetype=mustache: */}}
{{/*
Expand the name of the chart.
*/}}
{{- define "unleash.name" -}}
{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" -}}
{{- end -}}
{{/*
Create a default fully qualified app name.
We truncate at 63 chars because some K8S name fields are limited to this (by the DNS naming spec).
*/}}
{{- define "unleash.fullname" -}}
{{- if .Values.fullnameOverride -}}
{{- .Values.fullnameOverride | trunc 26 | trimSuffix "-" -}}
{{- else -}}
{{- $name := default .Chart.Name .Values.nameOverride -}}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" -}}
{{- end -}}
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