austinvalle
commented
1 month ago Hey there @magzim21 👋🏻, thanks for reporting the issue and sorry you're running into trouble here.
Functions, like templatefile, are executed as expressions, which means that your configuration would attempt to run templatefile during commands like terraform plan, despite the file not actually existing yet. The only way to avoid this execution is to supply that function with an unknown value, so Terraform knows it can't execute templatefile until the file path is known.
In your example local_file.template_helm_chart.filename is known during plan (since it's a hardcoded config value), so it attempts to execute the templatefile function, despite the file not existing yet.
I recreated this behavior with a gist template:
data "http" "remote_template" {
url = "https://gist.githubusercontent.com/austinvalle/2637d4ecf217b85515edadc9c1e6cce3/raw/7bf13430334e00df19fbdb19d18bb7c5130f16d6/local_file_example.txt"
}
resource "local_file" "test_file" {
content = data.http.remote_template.response_body
filename = "${path.module}/test_file.txt"
}
output "test" {
value = templatefile(
# Terraform already knows the value of `local_file.test_file.filename`, so running terraform plan will produce an error!
local_file.test_file.filename, {
msg = "hello world!"
}
)
}Running terraform plan with this config will give you an error:
│ Error: Invalid function argument
│
│ on main.tf line 13, in output "test":
│ 11: value = templatefile(
│ 12: # Terraform already knows the value of `local_file.test_file.filename`, so running terraform plan will produce an error!
│ 13: local_file.test_file.filename, {
│ 14: msg = "hello world!"
│ 15: }
│ 16: )
│ ├────────────────
│ │ while calling templatefile(path, vars)
│ │ local_file.test_file.filename is "./test_file.txt"
│
│ Invalid value for "path" parameter: no file exists at "./test_file.txt"; 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.One potential solution would be to work with the file contents directly, rather than attempting to write a file. Terraform v1.9 actually released a templatestring function that I believe could achieve what you're looking for.
Here is a rewrite of my previous failing configuration example:
data "http" "remote_template" {
url = "https://gist.githubusercontent.com/austinvalle/2637d4ecf217b85515edadc9c1e6cce3/raw/7bf13430334e00df19fbdb19d18bb7c5130f16d6/local_file_example.txt"
}
output "test" {
value = templatestring(
data.http.remote_template.response_body, {
msg = "hello world!"
}
)
}Running terraform plan
data.http.remote_template: Reading...
data.http.remote_template: Read complete after 0s [id=https://gist.githubusercontent.com/austinvalle/2637d4ecf217b85515edadc9c1e6cce3/raw/7bf13430334e00df19fbdb19d18bb7c5130f16d6/local_file_example.txt]
Changes to Outputs:
+ test = "hello world!"
You can apply this plan to save these new output values to the Terraform state, without changing any real infrastructure.
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Note: You didn't use the -out option to save this plan, so Terraform can't guarantee to take exactly these actions if you run
"terraform apply" now.Let me know if that's helpful or if you have any other questions!
magzim21
Terraform CLI and Provider Versions
terraform version ;terraform providers Terraform v1.8.2 on darwin_arm64
Your version of Terraform is out of date! The latest version is 1.8.5. You can update by downloading from https://www.terraform.io/downloads.html
Providers required by configuration: . ├── provider[registry.terraform.io/hashicorp/helm] ~> 2.13 ├── provider[registry.terraform.io/hashicorp/kubernetes] ~> 2.29 ├── provider[registry.terraform.io/hashicorp/local] ├── provider[registry.terraform.io/integrations/github] ~> 6.0 ├── provider[registry.terraform.io/hashicorp/tfe] ~> 0.55.0 ├── provider[registry.terraform.io/hashicorp/tls] ~> 3.0 └── provider[registry.terraform.io/hashicorp/aws] ~> 5.0
Providers required by state:
Terraform Configuration
Expected Behavior
It works
Actual Behavior
templatefileexepects the file to be present. It does not identify a dependency.Steps to Reproduce
terraform applyHow much impact is this issue causing?
Low
Logs
No response
Additional Information
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