How can I get .Values.someVal from values.yaml file or passed through cli inside a {{ range .Values.smtg }} loop?
for eg.
spec:
containers:
{{ range $k, $v := .Values.smtg }}
- name: {{ $k }}
image: {{ printf "%s:%s" (required "no img" $v) (required "no tag" .Values.someVal) | quote }} <<<--- how can I get .Values.someVal from values.yaml or cli?
{{- end }}
If I try to get them with .Values.smtg I will got : ... at <.Values.someVal>: nil pointer evaluating interface {}
Use $.Values.someVal. The $ will always point to the root context:
spec:
containers:
{{ range $k, $v := $.Values.smtg }}
- name: {{ $k }}
image: {{ printf "%s:%s" (required "no img" $v) (required "no tag" $.Values.someVal) | quote }}
{{- end }}
Related
I'm using a Helm chart to control what environment variables are set for a certain container in a deployment.
In my Values.yaml, I have an entry called env which is a dictionary:
image:
repository: xxxx.yyyyy.com/myimage
pullPolicy: IfNotPresent
# Enviroment variables that will be passed to the container.
env: {}
Now, I'll pass variables to the env dict using --set:
helm upgrade mydeployment chart --set env.VARIABLE=test
However, this must be transformed into a list to adhere to Kubernetes yaml:
spec:
template:
spec:
containers:
- name: {{ .Chart.Name }}
image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
imagePullPolicy: {{ .Values.image.pullPolicy }}
# This should come from that dict
env:
- name: VARIABLE
value: "test"
I don't know how to use the template language from Helm (sprig / go) to achieve that. Is it even possible?
To iterate through the map, the core Go text/template language provides a range keyword that can iterate through maps or arrays.
{{ range $key, $value := .Values.env }}
...
{{ end }}
Inside of this you can put arbitrary text. Helm doesn't require this to be any particular kind of YAML construct, just so long as the final result is valid YAML. For this setup a typical loop would look like
env:
{{- range $key, $value := .Values.env }}
- name: {{ quote $key }}
value: {{ quote $value }}
{{- end }}
You do need to be careful with indentation here. As a rule of thumb it often will work to include a - "swallow whitespace" indicator inside the open {{ and to not include one inside the close }}. The - name: must be at least as indented as the env: above it (ignoring the range line), and value: must be aligned with name:. I might put all of the template-language lines (the range and end) starting at the first column, even if they're embedded in a structure that's nested more.
spec:
template:
spec:
containers:
- name: {{ template "chart.fullname" . }}
env:
{{- range $key, $value := .Values.env }}
- name: {{ quote $key }}
value: {{ quote $value }}
{{- end }}
image: {{ .Values.registry }}/{{ .Values.image }}:{{ .Values.tag }}
I have a section in my values.yaml that looks like this:
env:
normal:
ENV_VAR_1: value
ENV_VAR_2: otherValue
secret:
secret-location:
ENV_VAR_USERNAME: username
ENV_VAR_PASSWORD: password
different-secret:
ENV_CONN_STRING: my_conn_string
I have a _helpers.tpl function like so:
{{/*
Add environment variables
*/}}
{{- define "helpers.list-env-variables" }}
{{- range $key, $val := .Values.env.normal }}
- name: {{ $key }}
value: {{ $val }}
{{- end }}
{{- range $name := .Values.env.secret }}
{{- }}
{{- range $key, $val := $name }}
- name: {{ $key }}
valueFrom:
secretKeyRef:
name: {{ $name }}
key: {{ $val }}
{{- end }}
{{- end }}
{{- end }}
and it's called in the deployment.yaml like you'd expect:
env:
{{- include "helpers.list-env-variables" . | indent 12 }}
So the normal environment variables get added just fine, but the secret ones don't. It specifies the secretKeyRef.name: value as map[ENV_VAR_USERNAME:username ENV_VAR_PASSWORD:password] instead of secret-key-ref.
helm debug output:
...
env:
- name: ENV_VAR_1
value: value
- name: ENV_VAR_2
value: otherValue
- name: ENV_VAR_PASSWORD
valueFrom:
secretKeyRef:
name: map[ENV_VAR_USERNAME:username ENV_VAR_PASSWORD:password]
key: password
- name: ENV_VAR_USERNAME
valueFrom:
secretKeyRef:
name: map[ENV_VAR_USERNAME:username ENV_VAR_PASSWORD:password]
key: username
- name: ENV_CONN_STRING
valueFrom:
secretKeyRef:
name: map[ENV_CONN_STRING:my_conn_string]
key: my_conn_string
I've already got all these secrets loaded into my K8s cluster (they get shared across a number of microservices, so I don't need to add new secrets which is what the default Helm template seems to want to do) - I just need to reference existing secrets.
My assumption here is that there's something I'm missing in my function to get the value of an element (e.g. "secret-location"), I just can't figure out what it is. If there's a different way I can structure my values.yaml to accomplish this, I'm game for that as well.
When obtaining secret data, it can also be obtained in the form of key-val.
Try replacing _helpers.tpl with the following
{{/*
Add environment variables
*/}}
{{- define "helpers.list-env-variables" }}
{{- range $key, $val := .Values.env.normal }}
- name: {{ $key }}
value: {{ $val }}
{{- end }}
{{- range $k, $v := .Values.env.secret }}
{{- }}
{{- range $key, $val := $v }}
- name: {{ $key }}
valueFrom:
secretKeyRef:
name: {{ $k }}
key: {{ $val }}
{{- end }}
{{- end }}
{{- end }}
I am defining a PrometheusRule as follow:
prometheusRule:
rules:
- alert: SSLCertExpiringSoon
expr: probe_ssl_earliest_cert_expiry - time() < 86400 * 10
for: 0m
labels:
severity: warning
annotations:
summary: Blackbox SSL certificate will expire soon (instance {{ $labels.instance }})
description: "SSL certificate expires in 30 days\n VALUE = {{ $value }}\n LABELS = {{ $labels }}"
And the template yml from helm chart:
{{- if .Values.prometheusRule.enabled }}
apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
name: {{ template "prometheus-blackbox-exporter.fullname" . }}
{{- with .Values.prometheusRule.namespace }}
namespace: {{ . }}
{{- end }}
labels:
{{- include "prometheus-blackbox-exporter.labels" . | nindent 4 }}
{{- with .Values.prometheusRule.additionalLabels -}}
{{- toYaml . | nindent 4 -}}
{{- end }}
spec:
{{- with .Values.prometheusRule.rules }}
groups:
- name: {{ template "prometheus-blackbox-exporter.name" $ }}
rules: {{ tpl (toYaml .) $ | nindent 8 }}
{{- end }}
{{- end }}
when I run helm template, tpl func it is not resolving the $labels and $values vars. When I remove annotations then the helm template is not complaining anymore. Where do fail?
error:
Error: template: prometheus-blackbox-exporter/templates/prometheusrule.yaml:18:16: executing "prometheus-blackbox-exporter/templates/prometheusrule.yaml" at <tpl (toYaml .) $>: error calling tpl: error during tpl function execution for "- alert: SSLCertExpiringSoon\n annotations:\n summary: Blackbox SSL certificate will expire soon (instance {{ $labels.instance\n }})\n expr: probe_ssl_earliest_cert_expiry - time() < 86400 * 10\n for: 0m\n labels:\n release: prometheus\n severity: warning\n- alert: SSLCertExpiringSoon\n annotations: null\n expr: probe_ssl_earliest_cert_expiry - time() < 86400 * 3\n for: 0m\n labels:\n severity: critical": parse error at (prometheus-blackbox-exporter/templates/prometheusrule.yaml:3): undefined variable "$labels"
Prometheus's alerting rules also use {{ ... $variable ... }} syntax, similar to Helm but with a different variant on the Go text/template syntax. When you pass this file through tpl, Helm tries to evaluate the embedded {{ ... }} template and evaluate any blocks there. Since $labels and $value aren't local variables defined at the Helm level, you get this error.
If you just want Prometheus to see this file as-is, and you don't need to replace anything at the Helm level (the file doesn't include references to .Values) then you don't need tpl
rules: {{ toYaml . | nindent 8 }}
If you do need tpl, then inside the included file you need to cause {{ to be emitted as a string and not processed as a template. One syntactic approach to it is to create a template block that prints out {{:
description: "VALUE = {{ "{{" }} $value }}"
# ^^^^^^^^^^ a {{ ... }} block that prints "{{"
The working version of syntax is as follow:
{{ `{{` }} $value }}
I have the following values file:
MYVAR: 12123
MYVAR2: 214123
I want to iterate over them and use them as env variables in my deployment template:
env:
{{- range .Values.examplemap }}
- name: {{ .name }}
value: {{ .value }}
{{- end }}
I tried this
For iterate over a map in helm you can try put this in the values.yaml
extraEnvs:
- name: ENV_NAME_1
value: value123
- name: ENV_NAME_2
value: value123
So in your template you must iterate the extraEnvs like this:
extraEnvs:
{{- range .Values.image.extraEnvs }}
- name: {{ .name | quote }}
value: {{ .value | quote }}
{{- end }}
In the core Go text/template language, the range operator can iterate over either a list or a map. There's specific syntax to assign the key-value pairs in a map to local variables:
env:
{{- $k, $v := range .Values.examplemap }}
- name: {{ $k }}
value: {{ $v }}
{{- end }}
I have a need to use variables inside of values.yaml file:
app:
version: 1.0
my_app1:
tag: {{ .app.version }} <- version taken from appVersion. In my case tag == version
Any help will be really appreciated.
app:
version: 1.0
my_app1:
tag: {{ .Values.app.version }}
{{ .Values.app | first | default .Values.app.version }}
You can also try this EDIT - 2
{{- range $key, $value := .Values.app }}
{{ $key }}: {{ $value }}
{{- end }}