anchor.diff:  
   === Environment Variables
   
  - * PG_MODE - either *master*, *replica* or *set*, this value determines whether
  + * PG_MODE - either *master*, *slave* or *set*, this value determines whether
      the database is set up as a master or replica instance, in the
      case of *set*, it means the container is started within a StatefulSet
      in a Kubernetes cluster.
  
positive.code:  * PG_MASTER_USER -  database user account to use when checking the database
     using pg_isready utility
   * PG_DATABASE - database to use when checking the database using pg_isready
   * REPLICA_TO_TRIGGER_LABEL - this is the pod name of a replica that you
     want to choose as the new master in a failover, this will override
     the normal replica selection
  
  
negative.code: 
   * create the trigger file on the replica that will become the new master
   * change the labels on the replica to be those of the master
   * start watching the new master in case that falls over next
   * look for replicas that have the metadata label value of *slavetype=trigger* to prefer
     the failover to. If found, it will use the first replica with that label,; if
     not found, it will use the first replica it finds.
  
  Example of looking for the failover replica:
  ....
  