helm-charts/docs/app-template/index.md

App Template

Background

Since Helm library charts cannot be installed directly I have created a companion chart for the common library.

Usage

This Helm chart can be used to deploy any application. Knowing the specifics of the application you want to deploy like the image, ports, env vars, args, and/or any config volumes will be required. You can also use Kubesearch to search for applications people have deployed with this Helm chart.

In order to use this template chart, you would deploy it as you would any other Helm chart. By setting the desired values, the common library chart will render the desired resources.

Be sure to check out the common library docs and its values.yaml for more information about the available configuration options.

Examples

This is an example values.yaml file that would deploy the vaultwarden application. For more deployment examples, check out the examples folder.

--8<--
examples/helm/vaultwarden/values.yaml
--8<--

Upgrade instructions

From 2.x.x to 3.0.x

The main changes from v2.x to v3.x are the removal of the default main objects and the introduction of JSON schema validation.

!!! warning

**IMPORTANT** The introduction of the json schema adds additional validations and restrictions on the contents of your chart values.
Things may have been missed during the initial schema creation, so if you run in to any unexpected validation errors please [raise an issue](https://github.com/bjw-s/helm-charts/issues/new?assignees=bjw-s&labels=bug&projects=&template=bug-report.md&title=)

Given the following real-life example values.yaml for app-template v2:

Expand

---
defaultPodOptions:
  securityContext:
    runAsUser: 568
    runAsGroup: 568
    fsGroup: 568
    fsGroupChangePolicy: "OnRootMismatch"
    supplementalGroups:
      - 65539

controllers:
  main:
    containers:
      main:
        image:
          repository: ghcr.io/onedr0p/sabnzbd
          tag: latest
          pullPolicy: IfNotPresent

service:
  main:
    ports:
      http:
        port: 8080

ingress:
  media:
    enabled: true
    className: "ingress-nginx"
    hosts:
      - host: sabnzbd.bjw-s.dev
        paths:
          - path: /
            service:
              name: main
              port: http

persistence:
  media:
    existingClaim: nas-media
    globalMounts:
      - path: /data/nas-media

The values for app-template v2.x would become this:

---
# yaml-language-server: $schema=https://raw.githubusercontent.com/bjw-s/helm-charts/common-3.0.0/charts/library/common/values.schema.json
defaultPodOptions:
  enableServiceLinks: true
  securityContext:
    runAsUser: 568
    runAsGroup: 568
    fsGroup: 568
    fsGroupChangePolicy: "OnRootMismatch"
    supplementalGroups:
      - 65539

controllers:
  sabnzbd: # this can now be any name you wish
    containers:
      app: # this can now be any name you wish
        image:
          repository: ghcr.io/onedr0p/sabnzbd
          tag: latest
          pullPolicy: IfNotPresent

        probes:
          liveness:
            enabled: true
          readiness:
            enabled: true
          startup:
            enabled: true
            spec:
              failureThreshold: 30
              periodSeconds: 5

service:
  app: # this can now be any name you wish
    controller: sabnzbd
    ports:
      http:
        port: 8080

ingress:
  media: # this can now be any name you wish
    className: "ingress-nginx"
    hosts:
      - host: sabnzbd.bjw-s.dev
        paths:
          - path: /
            service:
              identifier: app
              port: http

persistence:
  media:
    existingClaim: nas-media
    globalMounts:
      - path: /data/nas-media

Changes in this example

This is not meant as an exhaustive list of changes, but rather a "most common" example.

• The main object for controllers, containers, services and ingress has been removed from values.yaml and will therefore no longer provide any (both expected and unexpected) default values.
• The config object for persistence has been removed from values.yaml and will therefore no longer provide any (both expected and unexpected) default values.
• enableServiceLinks has been disabled by default. In order to explicitly enable serviceLinks, set the value to true.
• ingress.*.hosts.*.paths.*.service Service references now require either name or identifier to be set.
• Persistence items of type configMap and secret object references now allow either name or identifier to be set.

From 1.x.x to 2.0.x

!!! warning

**IMPORTANT** Because a new label has been introduced in the controller labelSelector (which is an immutable field), Deployments cannot be upgraded in place!
[More details](https://www.datree.io/resources/kubernetes-error-codes-field-is-immutable)

!!! info

Some items (Ingress, ports, persistence items, etc) now default to being enabled by default. However, this is not always the case for some of the `items due to overrides in the default `values.yaml`.
[More background](https://github.com/bjw-s/helm-charts/issues/205)

Given the following real-life example values.yaml for app-template v1:

Expand

image:
  repository: ghcr.io/onedr0p/sabnzbd
  tag: latest
  pullPolicy: IfNotPresent

podSecurityContext:
  runAsUser: 568
  runAsGroup: 568
  fsGroup: 568
  fsGroupChangePolicy: "OnRootMismatch"
  supplementalGroups:
    - 65539

service:
  main:
    ports:
      http:
        port: 8080

ingress:
  media:
    enabled: true
    ingressClassName: "ingress-nginx"
    hosts:
      - host: sabnzbd.bjw-s.dev
        paths:
          - path: /

persistence:
  media:
    enabled: true
    existingClaim: nas-media
    globalMounts:
      - path: /data/nas-media

probes:
  liveness:
    enabled: false
  readiness:
    enabled: false
  startup:
    enabled: false

The values for app-template v2.x would become this:

defaultPodOptions:
  securityContext:
    runAsUser: 568
    runAsGroup: 568
    fsGroup: 568
    fsGroupChangePolicy: "OnRootMismatch"
    supplementalGroups:
      - 65539

controllers:
  main:
    containers:
      main:
        image:
          repository: ghcr.io/onedr0p/sabnzbd
          tag: latest
          pullPolicy: IfNotPresent

        probes:
          liveness:
            enabled: false
          readiness:
            enabled: false
          startup:
            enabled: false

service:
  main:
    ports:
      http:
        port: 8080

ingress:
  media:
    enabled: true
    className: "ingress-nginx"
    hosts:
      - host: sabnzbd.bjw-s.dev
        paths:
          - path: /
            service:
              name: main
              port: http

persistence:
  media:
    existingClaim: nas-media
    globalMounts:
      - path: /data/nas-media

Changes in this example

This is not meant as an exhaustive list of changes, but rather a "most common" example.

• podSecurityContext has been moved to defaultPodOptions.securityContext. It is also possible to configure this on a controller-specific basis by moving it to controllers.main.pod.securityContext instead.
• image has been moved to controllers.main.containers.main.image so that multiple containers can be configured.
• ingress.media.ingressClassName has been renamed to ingress.main.className.
• ingress.media.enabled can be removed, since items are considered enabled by default (they can still be disabled by adding enabled: false).
• ingress.media.hosts.*.paths.*.service is now required since there is no more concept of a default "primary" service.
• persistence.media.mountPath has been moved to persistence.media.globalMounts.*.path to allow multiple mountPaths for the same persistence item.
• persistence.media.enabled can be removed, since items are considered enabled by default (they can still be disabled by adding enabled: false).
• probes has been moved to controllers.main.containers.main.probes so that multiple containers can be configured.

Source code

The source code for the app template chart can be found here.