implement readiness and liveness proble endpoints #2645
Description
I'm using hasura/graphql-engine:v1.0.0-beta.3 with Kubernetes.
In the Kubernetes deployment for a Hasura instance, I see that the /healthz endpoint is returning 500 when there are inconsistencies in the metadata.
Logs:
{"timestamp":"2019-07-31T05:43:21.049+0000","level":"warn","type":"metadata","detail":{"message":"Inconsistent Metadata!","info":{"objects":[{"definition":{"using":{"foreign_key_constraint_on":{"column":"city_id","table":"offers"}},"name":"offers","comment":null,"table":"cities"},"reason":"column \"city_id\" does not exist","type":"array_relation"},{"definition":{"using":{"foreign_key_constraint_on":{"column":"store_id","table":"offers"}},"name":"offers","comment":null,"table":"stores"},"reason":"column \"store_id\" does not exist","type":"array_relation"},{"definition":{"using":{"foreign_key_constraint_on":"store_id"},"name":"store","comment":null,"table":"offers"},"reason":"column \"store_id\" does not exist","type":"object_relation"},{"definition":{"using":{"foreign_key_constraint_on":"city_id"},"name":"city","comment":null,"table":"offers"},"reason":"column \"city_id\" does not exist","type":"object_relation"}]}}}
Quoting @shahidhk from the Discord discussion:
The pod is starting, but the health endpoint is more like a liveness probe