- https://deis.com/blog/2016/getting-started-authoring-helm-charts/
- https://docs.bitnami.com/kubernetes/how-to/
- https://github.com/kubernetes/helm/blob/master/docs/charts.md
- https://docs.helm.sh/chart-template-guide/
- http://helm.readthedocs.io/en/latest/architecture/
.
├── Chart.yaml --> metadata info
├── README.md
├── requirements.yaml --> define dependencies
├── templates
│ ├── spark-master-deployment.yaml --> configuration with template supported
│ ├── spark-worker-deployment.yaml
│ └── spark-zeppelin-deployment.yaml
│ └── NOTES.txt --> display when run "helm chart"
│ └── _helpers.tpl --> template handler
└── values.yaml --> variable list, will be interpolated on templates file during deployment
│
└── charts
├── apache/
├── Chart.yaml- Chart.yaml
name: The name of the chart (required)
version: A SemVer 2 version (required)
description: A single-sentence description of this project (optional)
keywords:
- A list of keywords about this project (optional)
home: The URL of this project's home page (optional)
sources:
- A list of URLs to source code for this project (optional)
maintainers: # (optional)
- name: The maintainer's name (required for each maintainer)
email: The maintainer's email (optional for each maintainer)
engine: gotpl # The name of the template engine (optional, defaults to gotpl)
icon: A URL to an SVG or PNG image to be used as an icon (optional).
appVersion: The version of the app that this contains (optional). This needn't be SemVer.
deprecated: Whether or not this chart is deprecated (optional, boolean)
tillerVersion: The version of Tiller that this chart requires. This should be expressed as a SemVer range: ">2.0.0" (optional)- requirements.yaml
Adding an
aliasfor a dependency chart would put a chart in dependencies using alias as name of new dependency.Condition- The condition field holds one or more YAML paths (delimited by commas). If this path exists in the top parent's values and resolves to a boolean value, the chart will be enabled or disabled based on that boolean value. Only the first valid path found in the list is evaluated and if no paths exist then the condition has no effect.Tags- The tags field is a YAML list of labels to associate with this chart. In the top parent's values, all charts with tags can be enabled or disabled by specifying the tag and a boolean value.Conditions(when set in values) always overridetags
dependencies:
- name: apache
version: 1.2.3
repository: http://example.com/charts
alias: new-subchart-1
condition: subchart1.enabled, global.subchart1.enabled
tags:
- front-end
- subchart1
- name: mysql
version: 3.2.1
repository: http://another.example.com/charts
alias: new-subchart-2
condition: subchart2.enabled,global.subchart2.enabled
tags:
- back-end
- subchart1 helm list --all
helm repo (list|add|update)
helm search
helm inspect <chart-name>
hem install --set a=b -f config.yaml <chart-name> -n <release-name> # --set take precedented, merge into -f
helm status <deployment-name>
helm delete <deployment-name>
helm inspect values <chart-name>
helm upgrade -f config.yaml <deployment-name> <chart-name>
helm rollback <deployment-name> <version>
helm create <chart-name>
helm package <chart-name>
helm lint <chart-name>
helm dep up <chart-name> # update dependency
helm get manifest <deployment-name> # prints out all of the Kubernetes resources that were uploaded to the server
helm install --debug --dry-run <deployment-name> # it will return the rendered template to you so you can see the output- --set outer.inner=value is translated into this:
outer:
inner: value- --set servers[0].port=80,servers[0].host=example:
servers:
- port: 80
host: example- --set name={a, b, c} translates to:
name:
- a
- b
- c- --set name=value1,value2:
name: "value1,value2"- --set nodeSelector."kubernetes.io/role"=master
nodeSelector:
kubernetes.io/role: master- --set livenessProbe.exec.command=[cat,docroot/CHANGELOG.txt] --set livenessProbe.httpGet=null
livenessProbe:
- httpGet:
- path: /user/login
- port: http
initialDelaySeconds: 120
+ exec:
+ command:
+ - cat
+ - docroot/CHANGELOG.txt- --timeout
- --wait
- --no-hooks
- --recreate-pods
Values that are supplied via a
values.yamlfile (or via the --set flag) are accessible from the.Valuesobject in a template
Release.Name:
Release.Time:
Release.Namespace: The namespace the chart was released to.
Release.Service: The service that conducted the release. Usually this is Tiller.
Release.IsUpgrade: This is set to true if the current operation is an upgrade or rollback.
Release.IsInstall: This is set to true if the current operation is an install.
Release.Revision: The revision number. It begins at 1, and increments with each helm upgrade.
Chart: The contents of the Chart.yaml. Thus, the chart version is obtainable as "Chart.Version" and the maintainers are in "Chart.Maintainers".
Files: Files can be accessed using {{index .Files "file.name"}} or using the "{{.Files.Get name}}" or "{{.Files.GetString name}}" functions. You can also access the contents of the file as []byte using "{{.Files.GetBytes}}"
Capabilities: "({{.Capabilities.KubeVersion}}", Tiller "({{.Capabilities.TillerVersion}}", and the supported Kubernetes API versions "({{.Capabilities.APIVersions.Has "batch/v1")"
{{.Files.Get config.ini}}
{{.Files.GetBytes}} useful for things like images
{{.Template.Name}}
{{.Template.BasePath}}- default value
{{default "minio" .Values.storage}}
//same
{{ .Values.storage | default "minio" }}- put a quote outside
heritage: {{.Release.Service | quote }}
# same result
heritage: {{ quote .Release.Service }}- global variable
global:
app: MyWordPress
// could be access as "{{.Values.global.app}}"- Includes a template called
mytpl.tpl, thenlowercasesthe result, then wraps that indouble quotes
value: {{include "mytpl.tpl" . | lower | quote}}requiredfunction declares an entry for.Values.whois required, and will print anerror messagewhen that entry is missing
value: {{required "A valid .Values.who entry required!" .Values.who }}- The
sha256sumfunction can be used together with theincludefunction to ensure a deployments template section is updated if another spec changes
kind: Deployment
spec:
template:
metadata:
annotations:
checksum/config: {{ include (print $.Template.BasePath "/secret.yaml") . | sha256sum }}
[...]-
The annotation
"helm.sh/resource-policy":keep instructsTillerto skip this resource during a helmdeleteoperation -
In the
templates/directory, any file that begins with anunderscore(_)isnotexpected to output a Kubernetes manifest file. So by convention,helper templatesandpartialsare placed in a_helpers.tplfile.
Read more
- include these annotation inside hook yaml file, for e.g
templates/post-install-job.yaml
apiVersion: batch/v1
kind: Job
metadata:
annotations:
# This is what defines this resource as a hook. Without this line, the
# job is considered part of the release.
"helm.sh/hook": post-install, post-upgrade
"helm.sh/hook-weight": "-5"Read more
Read more
Read more
{{ if PIPELINE }}
# Do something
{{ else if OTHER PIPELINE }}
# Do something else
{{ else }}
# Default case
{{ end }}
data:
myvalue: "Hello World"
drink: {{ .Values.favorite.drink | default "tea" | quote }}
food: {{ .Values.favorite.food | upper | quote }}
{{- if eq .Values.favorite.drink "lemonade" }}
mug: true
{{- end }} # notice the "-" in the left, if will help eliminate newline before variable
withcan allow you to set the currentscope(.) to a particular object
data:
myvalue: "Hello World"
{{- with .Values.favorite }}
drink: {{ .drink | default "tea" | quote }}
food: {{ .food | upper | quote }}
{{- end }} # instead of writing ".Values.favorite.drink"
Insideof therestricted scope, you willnotbe able to access the other objects from theparent scope
# predefined variable
pizzaToppings:
- mushrooms
- cheese
- peppers
- onions
toppings: |-
{{- range $i, $val := .Values.pizzaTopping }}
- {{ . | title | quote }} # upper first character, then quote
{{- end }}
sizes: |-
{{- range tuple "small" "medium" "large" }}
- {{ . }}
{{- end }} # make a quick listIt follows the form
$name. Variables are assigned with a special assignment operator::=
data:
myvalue: "Hello World"
{{- $relname := .Release.Name -}}
{{- with .Values.favorite }}
drink: {{ .drink | default "tea" | quote }}
food: {{ .food | upper | quote }}
release: {{ $relname }}
{{- end }}
# use variable in range
toppings: |-
{{- range $index, $topping := .Values.pizzaToppings }}
{{ $index }}: {{ $topping }}
{{- end }}
#toppings: |-
# 0: mushrooms
# 1: cheese
# 2: peppers
# 3: onions
{{- range $key,$value := .Values.favorite }}
{{ $key }}: {{ $value }}
{{- end }} # instead of specify the key, we can actually loop through the values.yaml file and print valuesThere is one variable that is always global - $ - this variable will always point to the root context
...
labels:
# Many helm templates would use `.` below, but that will not work,
# however `$` will work here
app: {{ template "fullname" $ }}
# I cannot reference .Chart.Name, but I can do $.Chart.Name
chart: "{{ $.Chart.Name }}-{{ $.Chart.Version }}"
release: "{{ $.Release.Name }}"
heritage: "{{ $.Release.Service }}"
...template names are
global
# _helpers.tpl
{{/* Generate basic labels */}}
{{- define "my_labels" }}
labels:
generator: helm
date: {{ now | htmlDate }}
version: {{ .Chart.Version }}
name: {{ .Chart.Name }}
{{- end }}When a named template (created with define) is rendered, it will receive the scope passed in by the template call.
# configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ .Release.Name }}-configmap
{{- template "my_labels" . }} # Notice the final dot, it will pass the global scope inside template file. Without it version & name will not be �generated.
{{- include "my_labels" . | indent 2 }} # similar to "template" directive, have the ability to control indentationreferable to use
includeovertemplate. Becausetemplateis anaction, and not afunction, there is no way to pass the output of a template call to other functions; the data is simply insertedinline.
# file located at parent folder
# config1.toml: |-
# message = config 1 here
# config2.toml: |-
# message = config 2 here
# config3.toml: |-
# message = config 3 here
data:
{{- $file := .Files }} # set variable
{{- range tuple "config1.toml" "config2.toml" "config3.toml" }} # create list
{{ . }}: |- # config file name
{{ $file.Get . }} # get file's content
{{- end }}apiVersion: v1
kind: ConfigMap
metadata:
name: conf
data:
+{{ (.Files.Glob "foo/*").AsConfig | indent 2 }}
---
apiVersion: v1
kind: Secret
metadata:
name: very-secret
type: Opaque
data:
+{{ (.Files.Glob "bar/*").AsSecrets | indent 2 }}
+token: |-
+ {{ .Files.Get "config1.toml" | b64enc }}# Force type
age: !!str 21
port: !!int "80"
# Fake first line to preserve integrity
coffee: | # �no strip
# Commented first line
Latte
Cappuccino
Espresso
coffee: |- # strip off trailing newline
Latte
Cappuccino
Espresso
coffee: |+ # preserve trailing newline
Latte
Cappuccino
Espresso
another: value
myfile: | # insert static file
{{ .Files.Get "myfile.txt" | indent 2 }}
coffee: > �# treat as one long line
Latte
Cappuccino
Espresso