devtools/gerrit: add simple healthcheck

This should somewhat temporarily fix gerrit outright dying (ie. refusing
to accept any new http connections) for no reason once in a while.

Change-Id: Ie0dfcab020945d17010c012ecfae19f4c8c5c374
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1601
Reviewed-by: q3k <q3k@hackerspace.pl>

devtools/gerrit/kube/gerrit.libsonnet

@@ -171,6 +171,15 @@ local kube = import "../../../kube/kube.libsonnet";
                             },
                             resources: cfg.resources,
                             volumeMounts_: volumeMounts,
+
+                            livenessProbe: {
+                                httpGet: {
+                                    path: "/",
+                                    port: 8080,
+                                },
+                                initialDelaySeconds: 60,
+                                periodSeconds: 10,
+                            },
                         },
                     },
                 },