Checking if a some value exists across many arrays which are selected as input.

[avo-sepp]

Hello!

I have a data structure which is a map of arrays.

{ "key1": ["string1", "string2"], "key2": ["string3", "string4"], "key3": ["string1", "string3"] }

I get an input which is an array of possible keys from the map.
data.input.keyInput = ["key1", "key3"]

I have a final data structure which contains an array of strings, which may or may not, exist under the keys.

data.stringValues = ["string3", "string4"]

The rule I'm looking to write should return true if some string in stringValues exists in any array whose key was input as keyInput.

So for this example, the rule would return true, because "string3" exists under "key3", and "key3" was an input provided by the user.

I'm new to Rego and not sure how I should structure this. I considered performing array.concat to combine all the keys under one array. But because I can get an arbitrary number of keys input, I don't know how to loop and concat all the key arrays together.

Any ideas that could point me in the right direction? Much appreciated.

[anderseknert]

Hi @avo-sepp 👋 There are many ways to do that, but here's an example: https://play.openpolicyagent.org/p/CHr9VZ9fa7

package play

import future.keywords.contains
import future.keywords.if
import future.keywords.in

map := {"key1": ["string1", "string2"], "key2": ["string3", "string4"], "key3": ["string1", "string3"]}

matches contains match if {
    some key in input.keyInput
    some match in map[key]
    match in data.stringValues
}

[avo-sepp]

Thank you! I'm still learning and this taught me a whole lot. I got my code working!

[anderseknert]

Great! What are you planning to use OPA for? If you don't mind me asking of course 😃 Just curious!