For the postgresql helper, hardened the code to get "the" cursor of the postgresql instance.
For the statuspage, a small status json is returned.
To find out what status a PostgreSQL cluster is in we use the cursor (instead of the provided query() function), as the query function does some retrying etc. For the healthcheck we want to simple provide an answer to a simple query, if we have to reconnect, we are not *that* healthy anyway.
Dropped catching exceptions in the do_GET block, as the HTTPServer will do that nicely for us anyway.
The StatusPage uses a BaseHTTPServer to server 3 simple http endpoints:
- pg_master, returns 200 if PostgreSQL is running as master
- pg_slave, returns 200 if PostgreSQL is running as slave
- pg_status, returns some information about the cluster
It does this by relying on the PostgreSQL connection of the Governor.
Create a superuser role with a given name and password (or change
the postgres role if the name is not given). Also, create an admin
role with the name and the password provided. The admin role has
CREATEDB and CREATEROLE permisssions, effectively making it the
most powerful role after the superuser.
When PostgreSQL is running inside the docker container, it should provide
the address of the host it's running on and not the address from inside
of the container to the outside world.
Feike Steenbergen