dockerfile: moved main script variables to Dockerfile

Dockerfile

@@ -2,7 +2,12 @@ FROM sameersbn/ubuntu:14.04.20150712
 MAINTAINER sameer@damagehead.com
 
 ENV PG_VERSION=9.4 \
-    PG_USER=postgres
+    PG_USER=postgres \
+    PG_HOME="/var/lib/postgresql"
+
+ENV PG_CONFDIR="/etc/postgresql/${PG_VERSION}/main" \
+    PG_BINDIR="/usr/lib/postgresql/${PG_VERSION}/bin" \
+    PG_DATADIR="${PG_HOME}/${PG_VERSION}/main"
 
 RUN wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - \
  && echo 'deb http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg main' > /etc/apt/sources.list.d/pgdg.list \

start

@@ -1,12 +1,6 @@
 #!/bin/bash
 set -e
 
-PG_HOME="/var/lib/postgresql"
-PG_CONFDIR="/etc/postgresql/${PG_VERSION}/main"
-PG_BINDIR="/usr/lib/postgresql/${PG_VERSION}/bin"
-PG_DATADIR="${PG_HOME}/${PG_VERSION}/main"
-PG_ARCHIVEDIR="${PG_HOME}/${PG_VERSION}/archive"
-
 # set this env variable to true to enable a line in the
 # pg_hba.conf file to trust samenet.  this can be used to connect
 # from other containers on the same host without authentication