Unable to pass boolean value to helm chart

[ocofaigh]

Terraform, Provider, Kubernetes and Helm Versions

Terraform version: v1.10.5
Provider version: v2.17.0
Kubernetes version: OCP 4.17 (Kubernetes 1.30)

Affected Resource(s)

• helm_release

Terraform Configuration Files

resource "helm_release" "cloud_monitoring_agent" {
  name             = "sysdig-agent"
  chart            = "sysdig-deploy"
  repository       = "https://charts.sysdig.com"
  version          = "1.89.0"
  namespace        = "ibm-observe"
  create_namespace = true
  timeout          = 1200
  wait             = true
  recreate_pods    = true
  force_update     = true
  reset_values     = true

  values = [
    yamlencode({
      agent = {
        extraVolumes = {
          volumes = [
            {
              name = "root-vol"
              hostPath = {
                path = "/"
              }
            },
            {
              name = "tmp-vol"
              hostPath = {
                path = "/tmp"
              }
            }
          ],
          mounts = [
            {
              mountPath = "/host"
              name      = "root-vol"
              readOnly  = true
            },
            {
              mountPath = "/host/tmp"
              name      = "tmp-vol"
            }
          ]
        }
      }
    })
  ]
}

Debug Output

Error: failed to replace object: DaemonSet in version "v1" cannot be handled as a DaemonSet: json: cannot unmarshal string into Go struct field VolumeMount.spec.template.spec.containers.volumeMounts.readOnly of type bool

From the terraform plan, I can see that this value is being passed as a string, and it seems the helm chart wants it to be a boolean

I can not figure out how to have this passed as a boolean by the helm provider so the helm chart deploy passes?

Panic Output

Steps to Reproduce

1. terraform apply

Expected Behavior

Actual Behavior

Important Factoids

References

• 🌱 Bump k8s.io/client-go from 0.27.1 to 0.28.1 #1234

Community Note

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[ocofaigh]

Hmm, this issue seems to be related with yamlencode - it seems to be converting HCL booleans to a string every time and hence why I'm getting the failure. As a workaround I have had to use raw yaml like this:

  values = [<<EOT
%{if var.enable_host_scanner || var.enable_kspm_analyzer~}
"agent":
  "extraVolumes":
    "mounts":
    - "mountPath": "/host"
      "name": "root-vol"
      "readOnly": true
    - "mountPath": "/host/tmp"
      "name": "tmp-vol"
    "volumes":
    - "hostPath":
        "path": "/"
      "name": "root-vol"
    - "hostPath":
        "path": "/tmp"
      "name": "tmp-vol"
%{endif~}
  ${local.settings}
EOT
  ]

However I would really prefer to maintain this config using HCL and convert it to yaml using yamllint if possible.

[dod38fr]

I have a similar, but reversed, problem where I cannot pass "true" as a string to the helm chart:

set = [for k, v in {
    "ingress.annotations.nginx\\.ingress\\.kubernetes\\.io/ssl-redirect" = "true"
 } : {
    name  = k
    value = v
  }]

The ssl-redirect value is passed as a boolean to helm:

ingress:
  annotations:
    nginx.ingress.kubernetes.io/ssl-redirect: true

This type change leads to this error:

Upgrade failed: unable to decode \"\": json: cannot unmarshal bool into Go struct field 
ObjectMeta.metadata.annotations of type string

[dennismdejong]

The Helm provider's set block uses Helm's strvals.ParseInto under the hood, which automatically detects value types — so true gets parsed as a boolean, 42 as an integer, etc. This auto-parsing can be surprising when you want to pass a boolean-like string to a chart.

Workaround: Use type = "string" to prevent auto-parsing:

set {
  name  = "someFlag"
  value = "true"
  type  = "string"
}

This ensures the value is passed as the literal string "true" rather than being interpreted as a boolean. For complex typed values, consider using the values attribute with yamlencode for full control over the YAML type representation.