Configuring custom Helm chart repositories - Working with Helm charts | Building Applications

Installing a Helm chart on an OKD cluster
Installing Helm charts using the Developer perspective
Using Helm in the web terminal
Creating a custom Helm chart on OKD
Adding custom Helm chart repositories
Creating credentials and CA certificates to add Helm chart repositories
Filtering Helm Charts by their certification level
Disabling Helm Chart repositories

You can install Helm charts on an OKD cluster using the following methods:

The CLI.
The Developer perspective of the web console.

The Developer Catalog, in the Developer perspective of the web console, displays the Helm charts available in the cluster. By default, it lists the Helm charts from the Red Hat OpenShift Helm chart repository. For a list of the charts, see the Red Hat Helm index file.

As a cluster administrator, you can add multiple Helm chart repositories, apart from the default one, and display the Helm charts from these repositories in the Developer Catalog.

Installing a Helm chart on an OKD cluster

Prerequisites

You have a running OKD cluster and you have logged into it.
You have installed Helm.

Procedure

Create a new project:
```
$ oc new-project mysql
```

Add a repository of Helm charts to your local Helm client:

$ helm repo add stable https://kubernetes-charts.storage.googleapis.com/

Example output

"stable" has been added to your repositories

Update the repository:
```
$ helm repo update
```

Install an example MySQL chart:

$ helm install example-mysql stable/mysql

Verify that the chart has installed successfully:

$ helm list

Example output

NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
example-mysql mysql 1 2019-12-05 15:06:51.379134163 -0500 EST deployed mysql-1.5.0 5.7.27

Installing Helm charts using the Developer perspective

You can use either the Developer perspective in the web console or the CLI to select and install a chart from the Helm charts listed in the Developer Catalog. You can create Helm releases by installing Helm charts and see them in the Developer perspective of the web console.

Prerequisites

You have logged in to the web console and have switched to the Developer perspective.

Procedure

To create Helm releases from the Helm charts provided in the Developer Catalog:

In the Developer perspective, navigate to the +Add view and select a project. Then click Helm Chart option to see all the Helm Charts in the Developer Catalog.
Select a chart and read the description, README, and other details about the chart.
Click Install Helm Chart.

Figure 1. Helm charts in developer catalog
In the Install Helm Chart page:
1. Enter a unique name for the release in the Release Name field.
2. Select the required chart version from the Chart Version drop-down list.
3. Configure your Helm chart by using the Form View or the YAML View.
  
  Where available, you can switch between the YAML View and Form View. The data is persisted when switching between the views.
4. Click Install to create a Helm release. You will be redirected to the Topology view where the release is displayed. If the Helm chart has release notes, the chart is pre-selected and the right panel displays the release notes for that release.

You can upgrade, rollback, or uninstall a Helm release by using the Actions button on the side panel or by right-clicking a Helm release.

Using Helm in the web terminal

You can use Helm by initializing the web terminal in the Developer perspective of the web console. For more information, see Using the web terminal.

Creating a custom Helm chart on OKD

Procedure

Create a new project:
```
$ oc new-project nodejs-ex-k
```

Download an example Node.js chart that contains OKD objects:

$ git clone https://github.com/redhat-developer/redhat-helm-charts

Go to the directory with the sample chart:

$ cd redhat-helm-charts/alpha/nodejs-ex-k/

Edit the Chart.yaml file and add a description of your chart:
```
apiVersion: v2 (1)
name: nodejs-ex-k (2)
description: A Helm chart for OpenShift (3)
icon: https://static.redhat.com/libs/redhat/brand-assets/latest/corp/logo.svg (4)
```
1 The chart API version. It should be v2 for Helm charts that require at least Helm 3.

2 The name of your chart.

3 The description of your chart.

4 The URL to an image to be used as an icon.

Verify that the chart is formatted properly:

$ helm lint

Example output

[INFO] Chart.yaml: icon is recommended

1 chart(s) linted, 0 chart(s) failed

Navigate to the previous directory level:
```
$ cd ..
```
Install the chart:
```
$ helm install nodejs-chart nodejs-ex-k
```

Verify that the chart has installed successfully:

$ helm list

Example output

NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
nodejs-chart nodejs-ex-k 1 2019-12-05 15:06:51.379134163 -0500 EST deployed nodejs-0.1.0  1.16.0

Adding custom Helm chart repositories

As a cluster administrator, you can add custom Helm chart repositories to your cluster and enable access to the Helm charts from these repositories in the Developer Catalog.

Procedure

To add a new Helm Chart Repository, you must add the Helm Chart Repository custom resource (CR) to your cluster.

Sample Helm Chart Repository CR

apiVersion: helm.openshift.io/v1beta1
kind: HelmChartRepository
metadata:
  name: <name>
spec:
 # optional name that might be used by console
 # name: <chart-display-name>
  connectionConfig:
    url: <helm-chart-repository-url>

For example, to add an Azure sample chart repository, run:

$ cat <<EOF | oc apply -f -
apiVersion: helm.openshift.io/v1beta1
kind: HelmChartRepository
metadata:
  name: azure-sample-repo
spec:
  name: azure-sample-repo
  connectionConfig:
    url: https://raw.githubusercontent.com/Azure-Samples/helm-charts/master/docs
EOF

Navigate to the Developer Catalog in the web console to verify that the Helm charts from the chart repository are displayed.

For example, use the Chart repositories filter to search for a Helm chart from the repository.

Figure 2. Chart repositories filter

If a cluster administrator removes all of the chart repositories, then you cannot view the Helm option in the +Add view, Developer Catalog, and left navigation panel.

Creating credentials and CA certificates to add Helm chart repositories

Some Helm chart repositories need credentials and custom certificate authority (CA) certificates to connect to it. You can use the web console as well as the CLI to add credentials and certificates.

Procedure

To configure the credentials and certificates, and then add a Helm chart repository using the CLI:

In the openshift-config namespace, create a ConfigMap object with a custom CA certificate in PEM encoded format, and store it under the ca-bundle.crt key within the config map:
```
$ oc create configmap helm-ca-cert \
--from-file=ca-bundle.crt=/path/to/certs/ca.crt \
-n openshift-config
```
In the openshift-config namespace, create a secret object to add the client TLS configurations:
```
$ oc create secret tls helm-tls-configs \
--cert=/path/to/certs/client.crt \
--key=/path/to/certs/client.key \
-n openshift-config
```
Note that the client certificate and key must be in PEM encoded format and stored under the keys tls.crt and tls.key, respectively.

Add the Helm repository as follows:

$ cat <<EOF | oc apply -f -
apiVersion: helm.openshift.io/v1beta1
kind: HelmChartRepository
metadata:
  name: <helm-repository>
spec:
  name: <helm-repository>
  connectionConfig:
    url: <URL for the Helm repository>
    tlsConfig:
        name: helm-tls-configs
    ca:
	name: helm-ca-cert
EOF

The ConfigMap and secret are consumed in the HelmChartRepository CR using the tlsConfig and ca fields. These certificates are used to connect to the Helm repository URL.

By default, all authenticated users have access to all configured charts. However, for chart repositories where certificates are needed, you must provide users with read access to the helm-ca-cert config map and helm-tls-configs secret in the openshift-config namespace, as follows:

$ cat <<EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: openshift-config
  name: helm-chartrepos-tls-conf-viewer
rules:
- apiGroups: [""]
  resources: ["configmaps"]
  resourceNames: ["helm-ca-cert"]
  verbs: ["get"]
- apiGroups: [""]
  resources: ["secrets"]
  resourceNames: ["helm-tls-configs"]
  verbs: ["get"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  namespace: openshift-config
  name: helm-chartrepos-tls-conf-viewer
subjects:
  - kind: Group
    apiGroup: rbac.authorization.k8s.io
    name: 'system:authenticated'
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: helm-chartrepos-tls-conf-viewer
EOF

Filtering Helm Charts by their certification level

You can filter Helm charts based on their certification level in the Developer Catalog.

Procedure

In the Developer perspective, navigate to the +Add view and select a project.
From the Developer Catalog tile, select the Helm Chart option to see all the Helm charts in the Developer Catalog.
Use the filters to the left of the list of Helm charts to filter the required charts:
- Use the Chart Repositories filter to filter charts provided by Red Hat Certification Charts or OpenShift Helm Charts.
- Use the Source filter to filter charts sourced from Partners, Community, or Red Hat. Certified charts are indicated with the () icon.

The Source filter will not be visible when there is only one provider type.

You can now select the required chart and install it.

Disabling Helm Chart repositories

You can disable Helm Charts from a particular Helm Chart Repository in the catalog by setting the disabled property in the HelmChartRepository custom resource to true.

Procedure

To disable a Helm Chart repository by using CLI, add the disabled: true flag to the custom resource. For example, to remove an Azure sample chart repository, run:

$ cat <<EOF | oc apply -f -
apiVersion: helm.openshift.io/v1beta1
kind: HelmChartRepository
metadata:
  name: azure-sample-repo
spec:
  connectionConfig:
   url:https://raw.githubusercontent.com/Azure-Samples/helm-charts/master/docs
  disabled: true
EOF

To disable a recently added Helm Chart repository by using Web Console:
1. Go to Custom Resource Definitions and search for the HelmChartRepository custom resource.
2. Go to Instances, find the repository you want to disable, and click its name.
3. Go to the YAML tab, add the disabled: true flag in the spec section, and click Save.
  Example
  spec: connectionConfig: url: <url-of-the-repositoru-to-be-disabled> disabled: true
  The repository is now disabled and will not appear in the catalog.

1	The chart API version. It should be `v2` for Helm charts that require at least Helm 3.
2	The name of your chart.
3	The description of your chart.
4	The URL to an image to be used as an icon.