Perform a complete rollback if one of the update steps fail #1250
Description
Description
PR: https://github.com/cortexlabs/cortex/pull/1387/files
There are two steps when updating an API. First the K8s resources are updated, and if that is successful, API gateway is updated. There is a possibility where K8s resources were updated successfully but the API Gateway update failed. If the user were updating the API endpoint in such a scenario, the API would still be considered as live in cortex get but it might not be reachable because of the mismatch routes between API Gateway and and the virtual service.
In order to determine whether a deployment of an API is a creation or an update to an existing API, the relevant k8s resources are queried. One solution to recover from partial failure is to do a complete rollback and apply the previous K8s resources and reapply the previous version of API Gateway.
The error message should contain the status of the rollback.