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HelmChart

A HelmChart custom resource enables the Replicated app manager to process and deploy Helm charts as part of an application. The app manager can process Helm charts using the Replicated Helm installation for existing applications. You can also use a native Helm installation for new applications or newly added Helm charts. For more information, see Helm Overview.

HelmChart custom resources are required for the app manager to deploy Helm charts. HelmChart custom resources are not required if only raw Kubernetes manifests are deployed.

The HelmChart custom resource manifest file references a required .tgz export of the Helm chart resources and provides the necessary instructions for processing and preparing the chart for deployment.

By default, the HelmChart custom resource uses the Replicated Helm installation, which uses the app manager to render and deploy Helm charts. For new installations, you can set useHelmInstall: true in the manifest to use the native Helm installation.

Deploying multiple instances of the same chart: You must add an additional HelmChart custom resource with a unique release name for each instance of the chart that is to be deployed as part of the application. However, only one .tgz of the chart needs to be included in the release.

The following is an example manifest file for the HelmChart custom resource:

apiVersion: kots.io/v1beta1
kind: HelmChart
metadata:
  name: samplechart
spec:
  # chart identifies a matching chart from a .tgz
  chart:
    name: samplechart
    chartVersion: 3.1.7
    releaseName: samplechart-release-1

  exclude: "repl{{ ConfigOptionEquals `include_chart` `include_chart_no`}}"

  # helmVersion identifies the Helm Version used to render the chart. Default is v3.
  helmVersion: v3

  # useHelmInstall identifies whether this Helm chart will use the
  # Replicated Helm installation (false) or native Helm installation (true). Default is false.
  # Native Helm installations are only available for Helm v3 charts.
  useHelmInstall: true

  # weight determines the order that charts with "useHelmInstall: true" are applied, with lower weights first.
  weight: 42

  # helmUpgradeFlags specifies additional flags to pass to the `helm upgrade` command.
  helmUpgradeFlags:
    - --skip-crds
    - --no-hooks
    - --timeout
    - 1200s
    - --history-max=15

  # values are used in the customer environment, as a pre-render step
  # these values will be supplied to helm template
  values:
    postgresql:
      enabled: repl{{ ConfigOptionEquals `postgres_type` `embedded_postgres`}}

  optionalValues:
    - when: "repl{{ ConfigOptionEquals `postgres_type` `external_postgres`}}"
      recursiveMerge: false
      values:
        postgresql:
          postgresqlDatabase: "repl{{ if ConfigOptionEquals `postgres_type` `external_postgres`}}repl{{ ConfigOption `external_postgres_database`}}repl{{ end}}"
          postgresqlUsername: "repl{{ if ConfigOptionEquals `postgres_type` `external_postgres`}}repl{{ ConfigOption `external_postgres_username`}}repl{{ end}}"
          postgresqlHost: "repl{{ if ConfigOptionEquals `postgres_type` `external_postgres`}}repl{{ ConfigOption `external_postgres_host`}}repl{{ end}}"
          postgresqlPassword: "repl{{ if ConfigOptionEquals `postgres_type` `external_postgres`}}repl{{ ConfigOption `external_postgres_password`}}repl{{ end}}"
          postgresqlPort: "repl{{ if ConfigOptionEquals `postgres_type` `external_postgres`}}repl{{ ConfigOption `external_postgres_port`}}repl{{ end}}"

  # namespace allows for a chart to be installed in an alternate namespace to
  # the default
  namespace: samplechart-namespace

  # builder values provide a way to render the chart with all images
  # and manifests. this is used in Replicated to create `.airgap` packages
  builder:
    postgresql:
      enabled: true

chart​

The chart key allows for a mapping between the data in this definition and the chart archive itself. More than one kind: HelmChart can reference a single chart archive, if different settings are needed.

chart.name​

The name of the chart. This must match the name field from a Chart.yaml in a .tgz chart archive that's also included in the release.

chart.chartVersion​

The version of the chart. This must match the version field from a Chart.yaml in a .tgz chart archive that's also included in the release.

chart.releaseName​

Introduced in Replicated app manager v1.73.0

Specifies the release name to be used when installing this instance of the Helm chart. Defaults to the chart name. The release name must be unique across all charts deployed in the namespace. Specifying a unique release name allows you to deploy multiple instances of the same Helm chart. Must be a valid Helm release name that matches regex ^[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$ and is no longer than 53 characters.

helmVersion​

Identifies the Helm Version used to render the chart. Acceptable values are v2 or v3. v3 is the default when no value is specified.

useHelmInstall​

Identifies whether this Helm chart will use the Replicated Helm installation (false) or native Helm installation (true). Default is false. It is recommended that you set this to true, because native Helm is preferred and Replicated Helm will be removed at some point. Native Helm installations always deploy using Helm v3.

weight​

Determines the order to apply charts that have useHelmInstall: true. Charts are applied by weight in ascending order, with lower weights applied first. Acceptable values are positive and negative integers, with a default value of 0.

For more information, see Defining Installation Order for Native Helm Charts.

helmUpgradeFlags​

note

helmUpgradeFlags is available in the app manager v1.75.0 and later.

Specifies additional flags to pass to the helm upgrade command for charts that have useHelmInstall: true. These flags are passed in addition to any flags the app manager passes by default. The values specified here take precedence if the app manager already passes the same flag.

The app manager uses helm upgrade for all deployments of an application (not just upgrades) by specifying the --install flag. For non-boolean flags that require an additional argument, such as --timeout 1200s, you must use an equals sign or specify the additional argument separately in the array. For example:

helmUpgradeFlags:
  - --timeout
  - 1200s
  - --history-max=15

values​

The values key allows for values to be changed in the chart. It also can create a mapping between the Replicated admin console configuration screen and the values. This mapping makes it possible to use the configuration screen in the admin console to control the Helm values.yaml file.

For more information about the configuration screen, see About the Configuration Screen.

The keys below values must map exactly to the keys in your values.yaml. Only include the keys below values that you want to change. These are merged with the values.yaml in the chart archive.

To exclude a value that is set in the Helm chart values.yaml, set the value equal to the string "null" (with quotes) in the values section of the HelmChart custom resource.

For more options, see the Allow deletion of a previous values file key pull request in the Helm repository in GitHub.

exclude​

The attribute is a value for making optional charts. The exclude attribute can be parsed by template functions. For more information about template functions, see About template function contexts.

When the app manager processes Helm charts, it excludes the entire chart if the output of the exclude field can be parsed as a boolean evaluating to true.

For more information about how the app manager processes Helm charts, see Helm processing.

optionalValues​

The optionalValues array supports advanced use cases where value overwrites must be dependent on a given condition evaluating to true.

Not all Helm charts treat "" and missing as the same value. If you need to have a value set that is always optional, and an empty string does not provide the same functionality as "not set", use the optionalValues key.

For more information about using optionalValues, see Including Optional Value Keys.

optionalValues[].when​

The when field in optionalValues provides a string-based method that is evaluated by template functions. The when field defers evaluation of the conditional to render time in the customer environment.

To write the when conditional statement, use template functions. For example, in the samplechart HelmChart custom resource above, the when field includes a conditional statement that evaluates to true if the user selects the external_postgres option on the admin console configuration screen:

optionalValues:
  - when: "repl{{ ConfigOptionEquals `postgres_type` `external_postgres`}}"

For more information about the syntax for template functions, see About Template Function Contexts.

optionalValues[].recursiveMerge​

note

recursiveMerge is available in the app manager v1.38.0 and later.

The recursiveMerge boolean defines how the app manager merges the values and optionalValues datasets when the conditional statement in the when field is true.

The admin console uses the values from this merged dataset and from the Helm chart values.yaml file when deploying the application.

The following table describes how values and optionalValues are merged based on the value of the recursiveMerge boolean:

ValueDescription
false (Default)

The values and optionalValues fields from the HelmChart custom resource manifest are not merged recursively.

The top level keys in optionalValues overwrite the top level keys in values.

true

The values and optionalValues fields from the HelmChart custom resource manifest are merged recursively.

All keys from values and optionalValues are included in the merged dataset.

In the case of a conflict where there is a matching key in optionalValues and values, the merged dataset uses the value of the key from optionalValues.

For example, a HelmChart custom resource manifest file defines the following datasets in the values and optionalValues fields:

values:
  favorite:
    drink:
      hot: tea
      cold: soda
    dessert: ice cream
    day: saturday

optionalValues:
  - when: '{{repl ConfigOptionEquals "example_config_option" "1" }}'
    recursiveMerge: false
    values:
      example_config_option:
        enabled: true
      favorite:
        drink:
          cold: lemonade

The values.yaml file for the associated Helm chart defines the following key value pairs:

favorite:
  drink:
    hot: coffee
    cold: soda
  dessert: pie

The templates/configmap.yaml file for the Helm chart maps these values to the following fields:

apiVersion: v1
kind: ConfigMap
metadata:
  name: test-configmap
data:
  favorite_day: {{ .Values.favorite.day }}
  favorite_dessert: {{ .Values.favorite.dessert }}
  favorite_drink_cold: {{ .Values.favorite.drink.cold }}
  favorite_drink_hot: {{ .Values.favorite.drink.hot }}

When recursiveMerge is set to false in the HelmChart custom resource manifest file, the ConfigMap for the deployed application includes the following key value pairs:

favorite_day: null
favorite_dessert: pie
favorite_drink_cold: lemonade
favorite_drink_hot: coffee

In this case, the top level keys in optionalValues overwrite the top level keys in values.

Then, the admin console uses the values from the Helm chart values.yaml to populate the remaining fields in the ConfigMap: favorite_day, favorite_dessert, and favorite_drink_hot.

When recursiveMerge is set to true, the ConfigMap for the deployed application includes the following key value pairs:

favorite_day: saturday
favorite_dessert: ice cream
favorite_drink_cold: lemonade
favorite_drink_hot: tea

In this case, all keys from values and optionalValues are included in the merged dataset. Both include favorite: > drink: > cold:, so the merged dataset uses lemonade from optionalValues.

namespace​

The namespace key specifies an alternative namespace where the app manager installs the Helm chart. By default, if no alternative namespace is provided, then the Helm chart is installed in the same namespace as the admin console.

If you specify a namespace in the HelmChart namespace field, you must also include the same namespace in the additionalNamespaces field of the Application custom resource manifest file. The app manager creates the namespaces listed in the additionalNamespaces field during installation. For more information, see additionalNamespaces in Application.

builder​

To create an .airgap bundle for a release that uses Helm charts, the Replicated vendor portal renders templates of the Helm charts with helm template. The builder key specifies the values from the Helm chart values.yaml file that the vendor portal uses to create the .airgap bundle.

The builder key has the following requirements and recommendations:

  • Replicated recommends that you include only the minimum Helm values in the builder key that are required to template the Helm chart with the correct image tags.
  • Use only static, or hardcoded, values in the builder key. You cannot use template functions in the builder key because values in the builder key are not rendered in a customer environment.
  • Any Helm values entries that are required for rendering Helm chart templates must have a value supplied in the builder key. For more information about the Helm required function, see Using the 'required' function.

Example

The following example demonstrates how to add a conditional postgresql resource to the builder key.

postgresql is defined as a conditional resource in the values key of the HelmChart custom resource:

  values:
    postgresql:
      enabled: repl{{ ConfigOptionEquals `postgres_type` `embedded_postgres`}}

As shown above, postgresql is included only when the user selects the embedded_postgres option.

To ensure the vendor portal includes this conditional postgresql resource in .airgap bundles, add the same postgresql value to the builder key with enabled set to true:

  builder:
    postgresql:
      enabled: true