COMPINFRA-4866: restrict alert_after values for tron/k8s

Author: jfongatyelp

docs/source/yelpsoa_configs.rst

@@ -1012,7 +1012,7 @@ Here is a list of options that PaaSTA will pass through:
 
  * ``alert_after``: Time string that represents how long a a check should be
    failing before an actual alert should be fired. Currently defaults to ``10m``
-   for the replication alert.
+   for the replication alert. See `pysensu-yelp documentation<https://pysensu-yelp.readthedocs.io/en/latest/#pysensu_yelp.human_to_seconds>` for accepted formats.
 
  * ``realert_every``: An integer (not a time unit) representing how many checks
    to execute between sending alerts. The default settings is ``-1``, which is

paasta_tools/cli/schemas/kubernetes_schema.json

@@ -502,6 +502,11 @@
                         },
                         "page": {
                             "type": "boolean"
+                        },
+                        "alert_after": {
+                            "type": "string",
+                            "pattern": "^[1-9]+[0-9]*[YMWDhms]$",
+                            "$comment": "See https://pysensu-yelp.readthedocs.io/en/latest/#pysensu_yelp.human_to_seconds"
                         }
                     },
                     "additionalProperties": true

paasta_tools/cli/schemas/tron_schema.json

@@ -622,7 +622,9 @@
                             "type": "string"
                         },
                         "alert_after": {
-                            "type": "string"
+                            "type": "string",
+                            "pattern": "^[1-9]+[0-9]*[YMWDhms]$",
+                            "$comment": "See https://pysensu-yelp.readthedocs.io/en/latest/#pysensu_yelp.human_to_seconds"
                         },
                         "check_that_every_day_has_a_successful_run": {
                             "type": "boolean"