Helm Charts#
Defining your extensions as Helm charts is one of two methods you can use to run k0s with your preferred extensions (the other being through the use of Manifest Deployer).
k0s supports two methods for deploying applications using Helm charts:
- Use Helm command in runtime to install applications. Refer to the Helm Quickstart Guide for more information.
- Insert Helm charts directly into the k0s configuration file,
k0s.yaml
. This method does not require a separate install ofhelm
tool and the charts automatically deploy at the k0s bootstrap phase.
Helm charts in k0s configuration#
Adding Helm charts into the k0s configuration file gives you a declarative way in which to configure the cluster. k0s controller manages the setup of Helm charts that are defined as extensions in the k0s configuration file.
Wait for install#
Each chart is processed the same way CLI tool does with following options:
--wait
--wait-for-jobs
It is possible to customize the timeout by using the `timeout' field.
Chart configuration#
Field | Default value | Description |
---|---|---|
name | - | Release name |
chartname | - | chartname in form "repository/chartname" or path to tgz file |
version | - | version to install |
timeout | - | timeout to wait for release install |
values | - | yaml as a string, custom chart values |
namespace | - | namespace to install chart into |
order | 0 | order to apply manifest. For equal values, alphanum ordering is used |
Example#
In the example, Prometheus is configured from "stable" Helms chart repository. Add the following to k0s.yaml
and restart k0s, after which Prometheus should start automatically with k0s.
spec:
extensions:
helm:
concurrencyLevel: 5
repositories:
- name: stable
url: https://charts.helm.sh/stable
- name: prometheus-community
url: https://prometheus-community.github.io/helm-charts
charts:
- name: prometheus-stack
chartname: prometheus-community/prometheus
version: "14.6.1"
timeout: 20m
order: 1
values: |
alertmanager:
persistentVolume:
enabled: false
server:
persistentVolume:
enabled: false
namespace: default
# We don't need to specify the repo in the repositories section for OCI charts
- name: oci-chart
chartname: oci://registry:8080/chart
version: "0.0.1"
order: 2
values: ""
namespace: default
# Other way is to use local tgz file with chart
# the file must exist on all controller nodes
- name: tgz-chart
chartname: /tmp/chart.tgz
version: "0.0.1"
order: 2
values: ""
namespace: default
Example extensions that you can use with Helm charts include:
- Ingress controllers: Nginx ingress, Traefix ingress (refer to the k0s documentation for Installing the Traefik Ingress Controller)
- Volume storage providers: OpenEBS, Rook, Longhorn
- Monitoring: Prometheus, Grafana
Helm debug logging#
Running k0s controller with --debug=true
enables helm debug logging.