How to load local file with cdktf for helm release? - terraform

Question

I'd like to reference a local yaml file when creating a helm chart with cdktf.
I have the following cdktf config:
{
"language": "typescript",
"app": "npx ts-node main.ts",
"projectId": "...",
"terraformProviders": [
"hashicorp/aws#~> 3.42",
"hashicorp/kubernetes# ~> 2.7.0",
"hashicorp/http# ~> 2.1.0",
"hashicorp/tls# ~> 3.1.0",
"hashicorp/helm# ~> 2.4.1",
"hashicorp/random# ~> 3.1.0",
"gavinbunney/kubectl# ~> 1.14.0"
],
"terraformModules": [
{
"name": "secrets-store-csi",
"source": "app.terraform.io/goldsky/secrets-store-csi/aws",
"version": "0.1.5"
}
],
"context": {
"excludeStackIdFromLogicalIds": "true",
"allowSepCharsInLogicalIds": "true"
}
}
Note npx ts-node main.ts as the app.
In main.ts I have the following helm release
new helm.Release(this, "datadog-agent", {
chart: "datadog",
name: "datadog",
repository: "https://helm.datadoghq.com",
version: "3.1.3",
set: [
{
name: "datadog.clusterChecks.enabled",
value: "true",
},
{
name: "clusterAgent.enabled",
value: "true"
},
],
values: ["${file(\"datadog-values.yaml\")}"],
});
Note that I'm referencing a yaml file called datadog-values.yaml similar to this example from the helm provider.
datadog-values.yaml is a sister file to main.ts
However, when I try to deploy this with cdktf deploy I get the following error
│ Error: Invalid function argument
│
│ on cdk.tf.json line 1017, in resource.helm_release.datadog-agent.values:
│ 1017: "${file(\"datadog-values.yaml\")}"
│
│ Invalid value for "path" parameter: no file exists at
│ "datadog-values.yaml"; this function works only with files that are
│ distributed as part of the configuration source code, so if this file will
│ be created by a resource in this configuration you must instead obtain this
goldsky-infra-dev ╷
│ Error: Invalid function argument
│
│ on cdk.tf.json line 1017, in resource.helm_release.datadog-agent (datadog-agent).values:
│ 1017: "${file(\"datadog-values.yaml\")}"
│
│ Invalid value for "path" parameter: no file exists at
│ "datadog-values.yaml"; this function works only with files that are
│ distributed as part of the configuration source code, so if this file will
│ be created by a resource in this configuration you must instead obtain this
│ result from an attribute of that resource.
To run a deployment I execute npm run deploy:dev which is a customer script in my package.json:
"build": "tsc",
"deploy:dev": "npm run build && npx cdktf deploy",
How can I reference my datadog yaml file in a helm release like in the example shown by the helm provider?

Answer 1

To reference local files in CDKTF, you need to use assets. Assuming at the root level of your project there's a values folder where you store your values yaml file:
const valuesAsset = new TerraformAsset(this, 'values-asset', {
path: `${process.cwd()}/values/${this.chartValues}`,
type: AssetType.FILE,
});
new HelmRelease(this, 'helm-release', {
name: this.releaseName,
chart: this.chartName,
repository: this.chartRepository,
values: [ Fn.file(valuesAsset.path) ]
})
}
Note that I've used the file Terraform function to read the content of the file.