How to fix my comparison of two values in my OPA rules? - terraform

Question

I would like to make comparison between two values in a OPA rule.
My OPA rule is :
package example
vm_name = input.planned_values.root_module.resources[0].values.name
vm_name_length = count(vm_name)
The output is :
~$ ./opa eval -i tfplan.json -d test1.rego "data.example"
{
"result": [
{
"expressions": [
{
"value": {
"vm_name": "XXXXXXXX",
"vm_name_length": 8
},
"text": "data.example",
"location": {
"row": 1,
"col": 1
}
}
]
}
]
}
I've tried to make a comparison between the length needed and the length of the VM name :
package example
vm_name = input.planned_values.root_module.resources[0].values.name
vm_name_length = count(vm_name)
if vm_name_length == 13 {
msg := "OK"
}
else {
msg := "Not ok"
}
But the output is :
{
"errors": [
{
"message": "unexpected assign token: non-terminated set",
"code": "rego_parse_error",
"location": {
"file": "test1.rego",
"row": 24,
"col": 7
},
"details": {
"line": " msg := \"OK\"",
"idx": 6
}
}
]
}
Does anyone know how to do that ?

Answer 1

Rego rules describe conditional assignment, so all conditions in the rule body (i.e. inside of the { ... }) will need to be true in order for the rule to evaluate the assignment.
package example
vm_name = input.planned_values.root_module.resources[0].values.name
vm_name_length = count(vm_name)
default msg := "Not ok"
msg := "OK" {
vm_name_length == 13
}