Hello,
Is it possible to do HCL-like list or map comprehensions (for loops) to transform maps and lists when these maps or lists are outputs from a module which are not known until apply-time and so are Tokens?
A contrived example in HCL (imagining that the local list is an output of some module):
locals {
emails = [
{
name = "fred",
email = "fred@foo.com"
},
{
name = "bob",
email = "bob@bar.com"
}
]
}
output "email_to_name_mapping" {
value = { for obj in local.emails : obj.email => obj.name }
}
Results in this output:
+ email_to_name_mapping = {
+ "bob@bar.com" = "bob"
+ "fred@foo.com" = "fred"
}
I cannot work out how to do a similar thing in CDKTF with Python, either with Python natively, or even with a HCL escape-hatch.
from constructs import Construct
from cdktf import App, TerraformStack, TerraformOutput, TerraformLocal, Token
class MyStack(TerraformStack):
def __init__(self, scope: Construct, id: str):
super().__init__(scope, id)
emails = TerraformLocal(self, "emails", [
{
"name": "fred",
"email": "fred@foo.com"
},
{
"name": "bob",
"email": "bob@bar.com"
}
])
for v in emails.as_list:
# Only one token in the list, I guess the token refers to the entire list, not a token per element, so I can't
# perform Python list-comprehension on each element as a Token (and each list element as a token would not have
# knowledge of the structure anyway, so no access to `name` or `email`)
print(v)
email_to_name_mapping_output = TerraformOutput(self, "email_to_name_mapping", value=emails) # As expected, it round-trips OK
# email_to_name_mapping_output = TerraformOutput(self, "email_to_name_mapping", value=emails.as_list) # As expected, it round-trips OK
# email_to_name_mapping_output.add_override("value", "{for obj in local.emails: obj.email => obj.name}") # Outputs the literal HCL
app = App()
MyStack(app, "cdktf-output-test")
app.synth()
In similar situations in the past, I have used the Fn API for related things (e.g. getting an element from a Token map not known until apply-time), but I do not think there are functions with the same utility as the native HCL for construct.
Anyone have any insight?
Thanks!