SSH-free PostgreSQL

All,

As I've started work on the Docker images for PostgreSQL, I've ended up
with the goal of trying to design a PostgreSQL system which doesn't
require SSHing into the server, to support the goal of one container =
one service. I think this is also a good goal for PostgreSQL because a
server which can be run without SSHing in is more manageable at scale.

Actually, it turns out that our set of things which need shell access
for 9.4 for most users are fairly limited:

(1) start/stop/restart
(2) pg_hba.conf changes
(3) pg_basebackup
(4) replica promotion
(5) log access

For Docker at least, (1) could be handled with a container restart.
Does that make sense?

(2) I think is doable by installing the pgAdmin adminpack. This will
also provide a postgresql.conf solution for 9.3.

(3) I'm thinking of doing this via parameterized (ENV for now) startup
of a Postgres container. That is, you start up the container, and set
$ROLE=replica and $MASTER="connection string", and on startup it does a
basebackup and starts replication. Make sense?

(4) I think the most sensible way to do this is via a pl/sh script, or
similar.

(5) For now we'll just make the logs output to Docker's stderr. In
time, we'll want to figure out a way to make this work with CSVlog, but
that's a problem to solve later.

So, comments? Ideas?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com