Bundle Overrides

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Bundle overrides provide a mechanism to customize Helm charts inside of Zarf packages.

Quickstart

Consider the following zarf.yaml and values.yaml which deploys podinfo with a couple of custom values:

# zarf.yaml
kind: ZarfPackageConfig
metadata:
  name: helm-overrides-package
  version: 0.0.1

components:
  - name: helm-overrides-component
    required: true
    charts:
      - name: podinfo
        version: 6.4.0
        namespace: podinfo
        url: https://github.com/stefanprodan/podinfo.git
        gitPath: charts/podinfo
        valuesFiles:
          - values.yaml
    images:
      - ghcr.io/stefanprodan/podinfo:6.4.0
---
# values.yaml
replicaCount: 1
ui:
  color: blue

The bundle overrides feature allows users to override the values specified in Zarf packages. For example:

kind: UDSBundle
metadata:
  name: helm-overrides
  description: testing a bundle with Helm overrides
  version: 0.0.1

packages:
  - name: helm-overrides-package
    path: "path/to/pkg"
    ref: 0.0.1

    overrides:
      helm-overrides-component:
        podinfo:
          valuesFiles:
            - values.yaml
          values:
            - path: "replicaCount"
              value: 2
          variables:
            - name: UI_COLOR
              path: "ui.color"
              description: "Set the color for podinfo's UI"
              default: "purple"

#values.yaml
podAnnotations:
  customAnnotation: "customValue"

This bundle will deploy the helm-overrides-package Zarf package and override the replicaCount, ui.color, and podAnnotations values in the podinfo chart. The values can’t be modified after the bundle has been created. However, at deploy time, users can override the UI_COLOR and other variables using a environment variable called UDS_UI_COLOR or by specifying it in a uds-config.yaml like so:

variables:
 helm-overrides-package:
   UI_COLOR: green

Overrides

Syntax

Consider the following bundle overrides:

packages:
  - name: helm-overrides-package
    path: "path/to/pkg"
    ref: 0.0.1

    overrides:
      helm-overrides-component: # component name inside of the helm-overrides-package Zarf pkg
        podinfo:                # chart name from the helm-overrides-component component
          valuesFiles:
            - values.yaml
          values:
            - path: "replicaCount"
              value: 2
          variables:
            - name: UI_COLOR
              path: "ui.color"
              description: "Set the color for podinfo's UI"
              default: "purple"

#values.yaml
podAnnotations:
  customAnnotation: "customValue"

In this example, the helm-overrides-package Zarf package has a component called helm-overrides-component which contains a Helm chart called podinfo; note how these names are keys in the overrides block. The podinfo chart has a replicaCount value that is overridden to 2, a podAnnotations value that is overridden to include customAnnotation: "customValue" and a variable called UI_COLOR that is overridden to purple.

Values Files

The valuesFiles in an overrides block are a list of file’s. It allows users to override multiple values in a Zarf package component’s underlying Helm chart, by providing a file with those values instead of having to include them all individually in the overrides block.

Values

The values in an overrides block are a list of path and value pairs. They allow users to override values in a Zarf package component’s underlying Helm chart. Note that values are specified by bundle authors and cannot be modified after the bundle has been created.

Path

The path uses dot notation to specify the location of a value to override in the underlying Helm chart. For example, the replicaCount path in the podinfo chart is located at the top-level of the podinfo values.yaml, so the path is simply replicaCount, while the ui.color path is located under the ui key, so the path is ui.color.

Value

The value is the value to set at the path. Values can be simple values such as numbers and strings, as well as, complex lists and objects, for example:

...
    overrides:
      helm-overrides-component:
        podinfo:
          values:
            - path: "podinfo.tolerations"
              value:
                - key: "unicorn"
                  operator: "Equal"
                  value: "defense"
                  effect: "NoSchedule"
            - path: podinfo.podAnnotations
              value:
                customAnnotation: "customValue"

Bundle Variables as Values

Bundle and Zarf variables can be used to set override values by using the syntax ${...}. For example:

# uds-config.yaml
variables:
  helm-overrides-package:
    replica_count: 2

kind: UDSBundle
metadata:
  name: example-bundle
  description: Example for using an imported variable to set an overrides value
  version: 0.0.1

packages:
  - name: output-var
    repository: localhost:888/output-var
    ref: 0.0.1
    exports:
      - name: COLOR

  - name: helm-overrides-package
    path: "../../packages/helm"
    ref: 0.0.1

    overrides:
      podinfo-component:
        unicorn-podinfo:
          values:
            - path: "podinfo.replicaCount"
              value: ${REPLICA_COUNT}
            - path: "podinfo.ui.color"
              value: ${COLOR}

In the example above ${REPLICA_COUNT} is set in the uds-config.yaml file and ${COLOR} is set as an export from the output-var package. Note that you could also set these values with the shared key in a uds-config.yaml, environment variables prefixed with UDS_ or with the --set flag during deployment.

Value Precedence

Value precedence is as follows:

The values in an overrides block
values set in the last valuesFile (if more than one specified)
values set in the previous valuesFile (if more than one specified)

Variables

Variables are similar to values in that they allow users to override values in a Zarf package component’s underlying Helm chart; they also share a similar syntax. However, unlike values, variables can be overridden at deploy time. For example, consider the variables key in the following uds-bundle.yaml:

kind: UDSBundle
metadata:
   name: example-bundle
   version: 0.0.1

packages:
   - name: helm-overrides-package
     path: "../../packages/helm"
     ref: 0.0.1"
     overrides:
        podinfo-component:
          unicorn-podinfo:
           variables:
           - name: UI_COLOR
             path: "ui.color"
             description: "Set the color for podinfo's UI"
             default: "purple"

There are 3 ways to override the UI_COLOR variable:

UDS config: you can create a uds-config.yaml file in the same directory as the bundle and specify the variable to override. For example, to override the UI_COLOR variable, you can create a uds-config.yaml:
```
  variables:
    helm-overrides-package:
      ui_color: green # Note that the variable for `UI_COLOR` can be upper or lowercase
```
Environment variables: you can create an environment variable prefixed with UDS_ and the name of the variable. For example, to override the UI_COLOR variable, you can create an environment variable called UDS_UI_COLOR and set it to the desired value. Note that environment variables take precedence over uds-config.yaml variables.
–set Flag: you can also override the variable using the CLI’s --set flag. For example, to override the UI_COLOR variable, you can run one of the following commands:
```
# by default ui_color will apply to all packages in the bundle
uds deploy example-bundle --set ui_color=green

# to specify a specific package that the variable should apply to you can prepend th package name to the variable
uds deploy example-bundle --set helm-overrides-package.ui_color=green
```
:warning: Warning: Because Helm override variables and Zarf variables share the same –set syntax, be careful with variable names to avoid conflicts.

Note

A variable that is not overridden by any of the methods above and has no default will be ignored.

Variable Precedence

Variable precedence is as follows:

The --set flag
Environment variables
uds-config.yaml variables
Variables default in theuds-bundle.yaml

Variable Types

Variables can be of either type raw or file. The type will default to raw if not set explicitly.

Caution

If a variable is set to accept a file as its value, but is missing the file type, then the file will not be processed.

kind: UDSBundle
metadata:
   name: example-bundle
   version: 0.0.1

packages:
   - name: helm-overrides-package
     path: "../../packages/helm"
     ref: 0.0.1
     overrides:
        podinfo-component:
          unicorn-podinfo:
           variables:
           - name: UI_COLOR
             path: "ui.color"
             description: "variable UI_COLOR accepts a raw value (e.g. a string, int, map) like "purple", which is passed to the ui.color helm path"
             type: raw
           - name: test_secret
             path: "testSecret"
             description: "variable TEST_SECRET will resolve to the contents of a file (e.g. test.cert), which gets passed to the testSecret helm path"
             type: file

File Paths

If a file path is not absolute, it will be set as relative to the uds-config.yaml directory.

e.g. the following uds-config.yaml is in src/test/bundles/07-helm-overrides/variable-files/

variables:
  helm-overrides:
    test_secret: test.cert

This means when test.cert is evaluated it will first be appended to the config path like so src/test/bundles/07-helm-overrides/variable-files/test.cert.

If the file path is already set to the same relative path as the config, then no merging will take place.

Note

UDS CLI does not encrypt or base64 encode any file contents before passing said data to Zarf or Helm.

For example, if the file contains a key to be used in a Kubernetes secret, it must be base64 encoded before being ingested by UDS CLI.

Namespace

It’s also possible to specify a namespace for a packaged Helm chart to be installed in. For example, to deploy the a chart in the custom-podinfo namespace, you can specify the namespace in the overrides block:

kind: UDSBundle
metadata:
   name: example-bundle
   version: 0.0.1

packages:
   - name: helm-overrides-package
     path: "../../packages/helm"
     ref: 0.0.1
     overrides:
        podinfo-component:
          unicorn-podinfo:
             namespace: custom-podinfo # custom namespace!
             values:
                - path: "podinfo.replicaCount"
                  value: 1

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