Check service is up, check connectivity between canary and endpoint.
A helpful application of https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/synthetics_canary
module "canaries" {
source = "github.com/kaihendry/terraform-canary"
schedule_expression = "rate(5 minutes)"
s3_artifact_bucket = "my-bucket-of-artifacts" # must pre-exist
alarm_email = "alarm@example.com" # you need to confirm this email address
endpoints = { "example" = { url = "https://example.com" }, "google" = { url = "https://google.com" } }
}