Read settings from config file (#714)

Dockerfile

@@ -1,11 +1,6 @@
 FROM debian:jessie
 
-ENV POSTGREST_VERSION 0.3.2.0
-ENV POSTGREST_SCHEMA public
-ENV POSTGREST_ANONYMOUS postgres
-ENV POSTGREST_JWT_SECRET thisisnotarealsecret
-ENV POSTGREST_MAX_ROWS 1000000
-ENV POSTGREST_POOL 200
+ENV POSTGREST_VERSION 0.4.0.0
 
 RUN apt-get update && \
     apt-get install -y tar xz-utils wget libpq-dev && \
@@ -16,12 +11,8 @@ RUN wget http://github.com/begriffs/postgrest/releases/download/v${POSTGREST_VER
     mv postgrest /usr/local/bin/postgrest && \
     rm postgrest-${POSTGREST_VERSION}-ubuntu.tar.xz
 
-CMD exec postgrest postgres://${PG_ENV_POSTGRES_USER}:${PG_ENV_POSTGRES_PASSWORD}@${PG_PORT_5432_TCP_ADDR}:${PG_PORT_5432_TCP_PORT}/${PG_ENV_POSTGRES_DB} \
-              --port 3000 \
-              --schema ${POSTGREST_SCHEMA} \
-              --anonymous ${POSTGREST_ANONYMOUS} \
-              --pool ${POSTGREST_POOL} \
-              --jwt-secret ${POSTGREST_JWT_SECRET} \
-              --max-rows ${POSTGREST_MAX_ROWS}
+# PostgREST reads /etc/postgrest.conf so map the configuration
+# file in when you run this container
+CMD exec postgrest
 
 EXPOSE 3000