How to Reference Two Dynamic Variables in Helm Templates?

[Lomanu4]

When creating Helm templates, referencing dynamic values can sometimes be tricky. In your case, you want to access two variables dynamically to retrieve a specific value from your values.yaml file based on the keys defined.

### Understanding the Problem
In the provided Helm template, you're trying to access a nested dictionary where both keys depend on dynamic values. Given the owners structure in values.yaml, you want to be able to reference the correct owner based on the dynamic $data_access.name. It's essential to correctly format the reference so that Helm understands which variable to use when fetching the value.

### The Helm Template Structure
Here's your original template code for quick reference:
```yaml {{- define "lib.keys" }} {{- $top := .top }} {{ range $data_access := $top.Values.data_accesses }} {{- $valuesPath := printf "data_accesses/%s/values.yaml" $data_access.name }} {{- $valuesDict := $top.Files.Get $valuesPath | fromYaml -}}

{{ $owners := $valuesDict.owners }}
{{ $ownerci := $owners.$data_access.name.ci }} #Getting error here


{{ -end }} <br>#### The Issue<br>The line `{{ $ownerci := $owners.$data_access.name.ci }}` leads to an error because Helm templates do not support direct variable interpolation like that. The `$data_access.name` cannot be resolved as a key dynamically in this context directly in that manner.<br><br>### Dynamic Variable Reference Solution<br>To resolve this issue, you can use the `index` function, which helps in dynamically referencing keys in a map. Here's how you can modify your code:<br>yaml {{- define "lib.keys" }} {{- $top := .top }} {{ range $data_access := $top.Values.data_accesses }} {{- $valuesPath := printf "data_accesses/%s/values.yaml" $data_access.name }} {{- $valuesDict := $top.Files.Get $valuesPath | fromYaml -}}

{{ $owners := $valuesDict.owners }}
{{ $ownerName := $data_access.name }}
{{ $ownerci := index $owners $ownerName "ci" }}


{{ -end }} <br>The `index` function allows you to extract values using multiple keys. In this case, you first retrieve the owner name and then utilize it to get the `ci` value from the `owners` map. This effectively references both the variables you need dynamically.<br><br>### Example values.yaml<br>Your `values.yaml` setup looks good, but ensure the structure is followed:<br>yaml owners: flow: ci: DB_AirFlow xyz: ci: DB_XYZ ```
Here, both flow and xyz are keys under owners, and ci provides the dynamic value you are aiming to achieve.

### Conclusion
In summary, when working with Helm templates involving dynamic values, it is crucial to utilize Helm functions like index to avoid referencing issues. This will help you effectively fetch dynamic values based on varying keys. If you encounter further issues or have additional questions, feel free to ask!

### Frequently Asked Questions
Q1: Can I use dot notation with dynamic keys in Helm templates?
A1: No, to reference dynamic keys, you should utilize functions like index to avoid access errors.
Q2: What if my values.yaml structure changes?
A2: Ensure your Helm templates are updated accordingly to reflect changes in the nested structure to avoid runtime errors.

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