Not able to render the helm template without quotes - kubernetes-helm

I have used almost all possible ways to render the helm template. But now I am out of ideas and seeking help:
values.yaml:
rollout:
namespace: xyz
project: default
baseDomain: "stage.danger.zone"
clusterDomain: cluster.local
manifest.yaml
apps:
certmanager:
source:
repoURL: 'https://artifactory.intern.example.io/artifactory/helm'
targetRevision: 0.0.6
chart: abc
helm:
releaseName: abc
values:
global:
imagePullSecrets:
- name: artifactory
baseDomain: "{{ .Values.rollout.baseDomain }}"
When I try to render the template using the below command in my main.yaml file that will produce the final result:
values: {{- tpl (toYaml $appValue.values | indent 6) $ }}
Expected result:
baseDomain: stage.danger.zone (without quotes)
What I am getting is:
baseDomain: 'stage.danger.zone'
If I try to remove the double quotes from: baseDomain: "{{ .Values.rollout.baseDomain }}", I get the following error:
[debug] error converting YAML to JSON: yaml: invalid map key: map[interface {}]interface {}{".Values.baseDomain":interface {}(nil)}
Any help or ideas to achieve the same?

This is an expected behaviour by YAML.
One dirty and bad hack would be
values: {{- tpl (toYaml $appValue.values | fromYaml | toYaml | indent 6) $ }}
and then you will not see the single quotes.
However, This is not a problem at all even if you have ' single quotes in your value. You can include this variable for example something like this below:
hosts:
- host: some-gateway.{{ .Values.rollout.baseDomain }}
serviceName: gateway
servicePort: 8080
path: /
Then it will show you your variable value without ' single quotes.
Example rendered output:
hosts:
- host: some-gateway.stage.danger.zone
path: /
serviceName: gateway
servicePort: 8080

Related

adding multiple ips/domains to filebeat.yml output.elasticsearch via helm

If have multiple elasticsearch/logstash nodes that you want to point them to the output.elasticsearch:hosts in filebeat.yml from the helm chart you can do like that:
values.yaml
note: define hosts as a string, not an array
logstash:
hosts: 192.168.1.2:5444', '192.168.2.100:5544
filebeat-deployment.yml
env:
- name: ELASTICSEARCH_HOSTS
{{- range $key, $val := .Values.logstash }}
value: {{ . | quote }}
{{- end }}
the results will be :
$ helm exec filebeat-pod cat /etc/filebeat/filebeat.yml -n filebeat
setup.template.overwrite: true
setup.ilm.enabled: false
output.elasticsearch:
hosts: ['192.168.1.2:5444', '192.168.2.100:5544']
#username:
#password:
#ssl.verification_mode:
#ssl.certificate_authorities:
#ssl.certificate:
#ssl.key:
filebeat pod logs
$ helm logs filebeat-pod -n filebeat
2022-10-04T09:54:04.539Z INFO eslegclient/connection.go:99 elasticsearch url: http://192.168.1.2:5444
2022-10-04T09:54:04.539Z INFO eslegclient/connection.go:99 elasticsearch url: http://192.168.2.100:5544
NOTE!! - if you have other solutions by adding the multiple ips/domains via helm chart to the ENV container, just reply to this.
Hope you will find this post helpful for you

Setting a list to a field in Helm

I have the following in my values.yaml
router:
env:
- name: JSON_LOGGING
value: True
In my Deployment I would simply like to set this list to the env field like so:
spec:
containers:
# ..
env: {{ $.Values.router.env }}
However, it appears that this produces an incorrect YAML file:
Error: UPGRADE FAILED: YAML parse error on translation/templates/translation-router.yaml: error converting YAML to JSON: yaml: line 35: did not find expected ',' or ']'
Is there a way to make this work?
You need to inline part of your configuration using toYaml.
spec:
containers:
# ..
env:
{{- toYaml .Values.rounter.env | nindent 6 }}

Error converting YAML to JSON: yaml: line 15: did not find expected alphabetic or numeric character

I want to set wildcard subdomain for my project, using k8s, nginx ingress controller, helm chart:
In ingress.yaml file:
...
rules:
- host: {{ .Values.ingress.host }}
...
In values.yaml file, I change host example.local to *.example.local:
...
ingress:
enabled: true
host: "*.example.local"
...
Then, when I install chart using helm chart:
Error: YAML parse error on example/templates/ingress.yaml: error converting YAML to JSON: yaml: line 15: did not find expected alphabetic or numeric character
How can I fix it?
Thank for your support.
YAML treats strings starting with asterisk in a special way - that's why the hostname with wildcards like *.example.local breaks the ingress on helm install.
In order to be recognized as strings, the values in ingress.yaml file should be quoted with " " characters:
...
rules:
- host: "{{ .Values.ingress.host }}"
...
One more option here - adding | quote :
...
rules:
- host: {{ .Values.ingress.host | quote }}
...
I've reproduced your issue, both these options worked correctly. More information on quoting special characters for YAML is here.
In your ingress.yaml put quotes around the host key.
host: "{{ .Values.ingress.host }}"
ingress:
enabled: true
host: "*.example.local"
you may need to use "---" instead of

Nested values are not able to be evaluated

I'm using helm v 3.7.0 and I have a parent chart with a few subcharts as dependancies.
One of the subcharts has a virtual service defined as per below.
Subchart Values.yaml:
ingress:
enabled: true
host: "hostname.local"
annotations: {}
tls: []
Subchart virtual.service.yaml:
{{- if .Values.ingress.enabled -}}
apiVersion: types.kubefed.io/v1beta1
kind: FederatedVirtualService
metadata:
name: {{ template "product.fullname" . }}-web-vservice
spec:
placement:
clusterSelector: {}
template:
spec:
gateways:
- {{ template "product.fullname" . }}-web-gateway
hosts:
- {{ .Values.ingress.host }}
http:
# Website
- match:
- uri:
prefix: /
route:
- destination:
host: {{ template "product.fullname" . }}-web
port:
number: 80
{{- end }}
When I run:
helm template . --debug
It errors out with:
Error: template: virtual.service.yaml:1:14: executing "virtual.service.yaml" at <.Values.ingress.enabled>: nil pointer evaluating interface {}.enabled
If I move the enabled boolean outside of ingress and update the if statement it works.
i.e.
new values:
ingressEnabled: true
ingress:
host: "hostname.local"
annotations: {}
tls: []
new virtual service:
{{- if .Values.ingressEnabled -}}
apiVersion: types.kubefed.io/v1beta1
kind: FederatedVirtualService
The problem is that this is happening all over the place with lots of different values but only where they are nested and I cannot make all values flat.
I have virtual services being specified in exactly the same way in other projects and they work perfectly. I don't believe the issue is with how I'm defining this (unless anyone can correct me?) so I think something else is preventing helm from being able to read nested values but I don't know where to look to investigate this odd behaviour.
What would make helm unable to read nested values?
Based on the comment above, I see you were able to overcome the issue and I want to add the answer to the question for other to find.
The default values.yaml file is lower case (even though we use .Values in the template).
What you can do is either:
make the filename start with a lowercase letter or
pass the values file explicitly with with -f option

How to pull environment variables with Helm charts

I have my deployment.yaml file within the templates directory of Helm charts with several environment variables for the container I will be running using Helm.
Now I want to be able to pull the environment variables locally from whatever machine the helm is ran so I can hide the secrets that way.
How do I pass this in and have helm grab the environment variables locally when I use Helm to run the application?
Here is some part of my deployment.yaml file
...
...
spec:
restartPolicy: Always
containers:
- name: sample-app
image: "sample-app:latest"
imagePullPolicy: Always
env:
- name: "USERNAME"
value: "app-username"
- name: "PASSWORD"
value: "28sin47dsk9ik"
...
...
How can I pull the value of USERNAME and PASSWORD from local environment variables when I run helm?
Is this possible? If yes, then how do I do this?
You can export the variable and use it while running helm install.
Before that, you have to modify your chart so that the value can be set while installation.
Skip this part, if you already know, how to setup template fields.
As you don't want to expose the data, so it's better to have it saved as secret in kubernetes.
First of all, add this two lines in your Values file, so that these two values can be set from outside.
username: root
password: password
Now, add a secret.yaml file inside your template folder. and, copy this code snippet into that file.
apiVersion: v1
kind: Secret
metadata:
name: {{ .Release.Name }}-auth
data:
password: {{ .Values.password | b64enc }}
username: {{ .Values.username | b64enc }}
Now tweak your deployment yaml template and make changes in env section, like this
...
...
spec:
restartPolicy: Always
containers:
- name: sample-app
image: "sample-app:latest"
imagePullPolicy: Always
env:
- name: "USERNAME"
valueFrom:
secretKeyRef:
key: username
name: {{ .Release.Name }}-auth
- name: "PASSWORD"
valueFrom:
secretKeyRef:
key: password
name: {{ .Release.Name }}-auth
...
...
If you have modified your template correctly for --set flag,
you can set this using environment variable.
$ export USERNAME=root-user
Now use this variable while running helm install,
$ helm install --set username=$USERNAME ./mychart
If you run this helm install in dry-run mode, you can verify the changes,
$ helm install --dry-run --set username=$USERNAME --debug ./mychart
[debug] Created tunnel using local port: '44937'
[debug] SERVER: "127.0.0.1:44937"
[debug] Original chart version: ""
[debug] CHART PATH: /home/maruf/go/src/github.com/the-redback/kubernetes-yaml-drafts/helm-charts/mychart
NAME: irreverant-meerkat
REVISION: 1
RELEASED: Fri Apr 20 03:29:11 2018
CHART: mychart-0.1.0
USER-SUPPLIED VALUES:
username: root-user
COMPUTED VALUES:
password: password
username: root-user
HOOKS:
MANIFEST:
---
# Source: mychart/templates/secret.yaml
apiVersion: v1
kind: Secret
metadata:
name: irreverant-meerkat-auth
data:
password: password
username: root-user
---
# Source: mychart/templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: irreverant-meerkat
labels:
app: irreverant-meerkat
spec:
replicas: 1
template:
metadata:
name: irreverant-meerkat
labels:
app: irreverant-meerkat
spec:
containers:
- name: irreverant-meerkat
image: alpine
env:
- name: "USERNAME"
valueFrom:
secretKeyRef:
key: username
name: irreverant-meerkat-auth
- name: "PASSWORD"
valueFrom:
secretKeyRef:
key: password
name: irreverant-meerkat-auth
imagePullPolicy: IfNotPresent
restartPolicy: Always
selector:
matchLabels:
app: irreverant-meerkat
You can see that the data of username in secret has changed to root-user.
I have added this example into github repo.
There is also some discussion in kubernetes/helm repo regarding this. You can see this issue to know about all other ways to use environment variables.
you can pass env key value from the value yaml by setting the deployment yaml as below :
spec:
restartPolicy: Always
containers:
- name: sample-app
image: "sample-app:latest"
imagePullPolicy: Always
env:
{{- range $name, $value := .Values.env }}
- name: {{ $name }}
value: {{ $value }}
{{- end }}
in the values.yaml :
env:
- name: "USERNAME"
value: ""
- name: "PASSWORD"
value: ""
when you install the chart you can pass the username password value
helm install chart_name --name release_name --set env.USERNAME="app-username" --set env.PASSWORD="28sin47dsk9ik"
For those looking to use data structures instead lists for their env variable files, this has worked for me:
spec:
containers:
- name: {{ .Chart.Name }}
image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
imagePullPolicy: {{ .Values.image.pullPolicy }}
env:
{{- range $key, $val := .Values.env }}
- name: {{ $key }}
value: {{ $val | quote }}
{{- end }}
values.yaml:
env:
FOO: "BAR"
USERNAME: "CHANGEME"
PASWORD: "CHANGEME"
That way I can access specific values by name in other parts of the helm chart and pass the sensitive values via helm command line.
To get away from having to set each secret manually, you can use:
export MY_SECRET=123
envsubst < values.yaml | helm install my-release . --values -
where ${MY_SECRET} is referenced in your values.yaml file like:
mychart:
secrets:
secret_1: ${MY_SECRET}
Helm 3.1 supports post rendering (https://helm.sh/docs/topics/advanced/#post-rendering) which passes the manifest to a script before it is actually send to Kubernetes API. Post rendering allows to manipulate the manifest in multiple ways (e.g. use kustomize on top of Helm).
The simplest form of a post renderer which replaces predefined environment values could look like this:
#!/bin/sh
envsubst <&0
Note this will replace every occurance of $<VARNAME> which could collide with variables in the templates like shell scripts in liveness probes. So better explicitly define the variables you want to get replaced: envsubst '${USERNAME} ${PASSWORD}' <&0
Define your env variables in the shell:
export USERNAME=john PASSWORD=my-secret
In the tempaltes (e.g. secret.yaml) use the values defined in the values.yaml:
apiVersion: v1
kind: Secret
metadata:
name: {{ .Release.Name }}-auth
data:
username: {{ .Values.username }}
password: {{ .Values.password }}
Note that you can not apply string transformations like b64enc on the strings as the get injected in the manifest after Helm has already processed all YAML files. Instead you can encode them in the post renderer if required.
In the values.yaml use the variable placeholders:
...
username: ${USERNAME}
password: ${PASSWORD}
The parameter --post-renderer is supported in several Helm commands e.g.
helm install --dry-run --post-renderer ./my-post-renderer.sh my-chart
By using the post renderer the variables/placeholders automatically get replaced by envsubst without additional scripting.
i guess the question is how to lookup for env variable inside chart by looking at the env variables it-self and not by passing this with --set.
for example: i have set a key "my_db_password" and want to change the values by looking at the value in env variable is not supported.
I am not very sure on GO template, but I guess this is disabled as what they explain in helm documentation. "We removed two for security reasons: env and expandenv (which would have given chart authors access to Tiller’s environment)." https://helm.sh/docs/developing_charts/#know-your-template-functions
I think one simple way is just set the value directly. for example, in your Values.yml, you want pass the service name:
...
myapp:
service:
name: ""
...
Your service.yml just use this value as usual:
{{ .Values.myapp.service.name }}
Then to set the value, use --set, like: --set myapp.service.name=hello
Then, for example, if you want to use the environment variable, do export before that:
#set your env variable
export MYAPP_SERVICE=hello
#pass it to helm
helm install myapp --set myapp.service.name=$MYAPP_SERVICE.
If you do debug like:
helm install myapp --set myapp.service.name=$MYAPP_SERVICE --debug --dry-run ./myapp
You can see this information at the beginning of your yml which your "hello" was set.
USER-SUPPLIED VALUES:
myapp:
service:
name: hello
As an alternative to pass local environment variables, I like to store these kind of sensitive values in a folder ignored by your VCS, and use Helm .Files object to read them and provide the values to your templates.
In my opinion, the advantage is that it doesn't require the host that will operate the Helm chart to set any OS specific environment variable, and makes the chart self-contained whilst not exposing these values.
# In a folder not committed, e.g. <chart_base_directory>/secrets
username: app-username
password: 28sin47dsk9ik
Then in your chart templates:
# In deployment.yaml file
---
apiVersion: v1
kind: Secret
metadata:
name: {{ .Release.Name }}-auth
stringData::
{{ .Files.Get "<chart_base_directory>/secrets" | indent 2 }}
As a result, everything the Chart needs is accessible from within the directory where you define everything else. And instead of setting system-wide env vars, it just needs a file.
This file can be generated automatically, or copied from a committed template with dummy values. Helm will also fire an error early on install/update if this isn't defined, as opposed to creating your secret with username="" and password="" if your env vars haven't been defined, which only becomes obvious once your changes are applied to the cluster.