Common functions

This offer all the function from a default Helm chart and in addition: common.podConfig, common.containerConfig

The signature of common.name, common.fullname, common.labels, common.selectorLabels and common.serviceAccountName is changed to add the serviceName.

Then you can quickly define a deployment like this:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "common.fullname" ( dict "root" . "service" .Values ) }}
  {{- include "common.metadata" ( dict "root" . "service" .Values ) | nindent 2 }}
spec:
  replicas: {{ .Values.replicaCount }}
  strategy:
    type: RollingUpdate
  selector:
    matchLabels: {{- include "common.selectorLabels" ( dict "root" . "service" .Values ) | nindent 6 }}
  template:
    metadata: {{- include "common.podMetadata" ( dict "root" . "service" .Values ) | nindent 6 }}
    spec: {{- include "common.podConfig" ( dict "root" . "service" .Values ) | nindent 6 }}
      containers:
        - name: "main"
          {{- include "common.containerConfig" ( dict "root" . "container" .Values ) | nindent 10 }}

In general it do the same thing than the default Helm chart, the following chapter describe the specific things.

Good example of using most of the functions.

Service name

common.servicenamePostfix

Expand the name of the chart.

Parameters:

• service: the service object.
• serviceName: the service name default value (optional).

Used values: serviceName.

common.nameNoTrunc

Expand the name of the chart.

Parameters:

• root: the root object, should be $.
• service: the service object.

Used values: nameOverride.

common.name

Expand the name of the chart.

Parameters:

• root: the root object, should be $.
• service: the service object.

Used values: nameOverride, nameTrunc.

Used functions:

• common.nameNoTrunc

common.releaseNameNoTrunc

Expand the name of the release.

Parameters:

• root: the root object, should be $.
• service: the service object.

Used values: releaseNameOverride.

common.releaseName

Expand the name of the release.

Parameters:

• root: the root object, should be $.
• service: the service object.

Used values: releaseNameOverride, releaseTrunc.

Used functions:

• common.releaseNameNoTrunc

common.fullname

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.

The full name is the concatenation of a prefix, and a service name <prefix>-<service-name>.

Where the prefix is the release name or the chart name (also just named name) of the chart <release-name>-<chart-name>.

Parameters:

• root: the root object, should be $.
• service: the service object.

Used values: releaseNameOverride, nameOverride, fullnameOverride, releaseTrunc, nameTrunc, prefixTrunc.

Used functions:

• common.releaseName
• common.name
• common.servicenamePostfix

common.chart

Create chart name and version as used by the chart label.

The root ($) should be directly passed as parameter.

common.labels

Create the labels for the service.

Parameters:

• root: the root object, should be $.

Used values:

Used functions:

• common.chart
• common.selectorLabels

common.selectorLabels

Create the selector labels for the service.

Parameters:

• root: the root object, should be $.
• service: the service object.
• serviceName: the service name default value (optional).

Used values:

• serviceName from the service object.

Used functions:

• common.name

common.dictToList

Convert a dictionary to a list.

Used to pass a dictionary to Kubernetes but configure a dict in the values to ve able to override them.

Example, by default this:

name_1:
  key: value
name_2:
  key: value

is transformed into this:

- name: name_1
  key: value
- name: name_2
  key: value

Parameters:

• keyName: the name of the key to use in the list (default is 'name').

common.metadata

Create the metadata for the Kubernetes object.

Parameters:

• service: the service object.

Used values:

• labels from the service object.
• annotations from the service object.

Used functions:

• common.labels

Schema documentation

Documentation based on the schema defined in values.md.

Pre commit hooks

pre-commit hook used to generate and check your expected template.

Adding to your .pre-commit-config.yaml

ci:
  skip:
    - heml-template-gen

repos:
  - repo: https://github.com/camptocamp/helm-common
    rev: <version> # Use the ref you want to point at
    hooks:
      - id: helm-template-gen
        files: |-
          (?x)(
            ^templates/.*$
            |^values\.yaml$
            |^Chart\.yaml$
            |tests/values\.yaml$
          )
        args:
          - --values=tests/values.yaml
          - release-name
          - .
          - tests/expected.yaml

Contributing

Install the pre-commit hooks:

pip install pre-commit
pip install -e .
pre-commit install --allow-missing-config