text: -- policy for monitoring which VMs do not have instance HA configured
  CREATE SCHEMA vm_ha;
  
  -- ignore a VM if it has one of these tags
  CREATE TABLE vm_ha._except_tag AS
  SELECT * FROM (VALUES ('transient'), ('dev'), ('test')) AS t (tag);
  
  -- wrap the table in a view to allow easier extension if the list
  -- of tags should be a query rather than a base table.
  CREATE VIEW vm_ha.except_tag AS SELECT * FROM vm_ha._except_tag;
  
  -- `warning` view consisting of VMs which do not have HA configured
  CREATE VIEW vm_ha.warning AS
  SELECT d->>'id' AS server_id
  FROM   _compute.servers
  WHERE  NOT d->'tags' ?| (SELECT array_agg(tag) FROM vm_ha.except_tag)
  AND    NOT d->'metadata' @> '{"HA_Enabled": true}';
  