add postgres:9.5-alpine variant

build it from source

9.5/alpine/Dockerfile

@@ -0,0 +1,81 @@
+# vim:set ft=dockerfile:
+FROM alpine:3.3
+
+# explicitly set user/group IDs
+#RUN adduser -S -G postgres -u 999 postgres
+
+# make the "en_US.UTF-8" locale so postgres will be utf-8 enabled by default
+ENV LANG en_US.utf8
+
+RUN mkdir /docker-entrypoint-initdb.d
+
+ENV PG_MAJOR 9.5
+ENV PG_VERSION 9.5.0
+ENV PG_SHA256 f1c0d3a1a8aa8c92738cab0153fbfffcc4d4158b3fee84f7aa6bfea8283978bc
+
+
+# configure options taken from:
+# https://anonscm.debian.org/cgit/pkg-postgresql/postgresql.git/tree/debian/rules?h=9.5
+RUN set -x \
+	&& apk add --no-cache --virtual .build-deps \
+		su-exec \
+		bash \
+		bison \
+		curl \
+		flex \
+		gcc \
+		krb5-dev \
+		libc-dev \
+		libedit-dev \
+		libxml2-dev \
+		libxslt-dev \
+		make \
+		openldap-dev \
+		openssl-dev \
+		perl \
+		perl-dev \
+		python3-dev \
+		tcl-dev \
+		util-linux-dev \
+		zlib-dev \
+	&& curl -fSL "https://ftp.postgresql.org/pub/source/v$PG_VERSION/postgresql-$PG_VERSION.tar.bz2" -o postgresql.tar.bz2 \
+	&& echo "$PG_SHA256  postgresql.tar.bz2" | sha256sum -c - \
+	&& mkdir -p /usr/src \
+	&& tar -jxf postgresql.tar.bz2 -C /usr/src \
+	&& rm postgresql.tar.bz2 \
+	&& cd /usr/src/postgresql-$PG_VERSION \
+	&& ./configure \
+		--enable-integer-datetimes \
+		--enable-tap-tests \
+		--enable-thread-safety \
+		--prefix=/usr/local \
+		--with-libedit-preferred \
+		--with-openssl \
+		--with-uuid=e2fs \
+	&& make -j$(getconf _NPROCESSORS_ONLN) world \
+	&& make install-world \
+	&& make -C contrib install \
+	&& runDeps="$( \
+		scanelf --needed --nobanner --recursive /usr/local \
+			| awk '{ gsub(/,/, "\nso:", $2); print "so:" $2 }' \
+			| sort -u \
+			| xargs -r apk info --installed \
+			| sort -u \
+	)" \
+	&& apk add --virtual .postgresql-rundeps $runDeps su-exec \
+	&& apk del .build-deps \
+	&& cd / && rm -rf /usr/src/postgresql-* /usr/local/include/* \
+	&& find /usr/local -name '*.a' -delete
+
+RUN mkdir -p /var/run/postgresql && chown -R postgres /var/run/postgresql
+
+ENV PATH /usr/lib/postgresql/$PG_MAJOR/bin:$PATH
+ENV PGDATA /var/lib/postgresql/data
+VOLUME /var/lib/postgresql/data
+
+COPY docker-entrypoint.sh /
+
+ENTRYPOINT ["/docker-entrypoint.sh"]
+
+EXPOSE 5432
+CMD ["postgres"]

9.5/alpine/docker-entrypoint.sh

@@ -0,0 +1,96 @@
+#!/bin/sh -e
+
+set_listen_addresses() {
+	sedEscapedValue="$(echo "$1" | sed 's/[\/&]/\\&/g')"
+	sed -ri "s/^#?(listen_addresses\s*=\s*)\S+/\1'$sedEscapedValue'/" "$PGDATA/postgresql.conf"
+}
+
+if [ "$1" = 'postgres' ]; then
+	mkdir -p "$PGDATA"
+	chmod 700 "$PGDATA"
+	chown -R postgres "$PGDATA"
+
+	chmod g+s /var/run/postgresql
+	chown -R postgres /var/run/postgresql
+
+	# look specifically for PG_VERSION, as it is expected in the DB dir
+	if [ ! -s "$PGDATA/PG_VERSION" ]; then
+		su-exec postgres initdb
+
+		# check password first so we can output the warning before postgres
+		# messes it up
+		if [ "$POSTGRES_PASSWORD" ]; then
+			pass="PASSWORD '$POSTGRES_PASSWORD'"
+			authMethod=md5
+		else
+			# The - option suppresses leading tabs but *not* spaces. :)
+			cat >&2 <<-'EOWARN'
+				****************************************************
+				WARNING: No password has been set for the database.
+				         This will allow anyone with access to the
+				         Postgres port to access your database. In
+				         Docker's default configuration, this is
+				         effectively any other container on the same
+				         system.
+
+				         Use "-e POSTGRES_PASSWORD=password" to set
+				         it in "docker run".
+				****************************************************
+			EOWARN
+
+			pass=
+			authMethod=trust
+		fi
+
+		{ echo; echo "host all all 0.0.0.0/0 $authMethod"; } >> "$PGDATA/pg_hba.conf"
+
+		# internal start of server in order to allow set-up using psql-client		
+		# does not listen on TCP/IP and waits until start finishes
+		su-exec postgres pg_ctl -D "$PGDATA" \
+			-o "-c listen_addresses=''" \
+			-w start
+
+		: ${POSTGRES_USER:=postgres}
+		: ${POSTGRES_DB:=$POSTGRES_USER}
+		export POSTGRES_USER POSTGRES_DB
+
+		if [ "$POSTGRES_DB" != 'postgres' ]; then
+			psql --username postgres <<-EOSQL
+				CREATE DATABASE "$POSTGRES_DB" ;
+			EOSQL
+			echo
+		fi
+
+		if [ "$POSTGRES_USER" = 'postgres' ]; then
+			op='ALTER'
+		else
+			op='CREATE'
+		fi
+
+		psql --username postgres <<-EOSQL
+			$op USER "$POSTGRES_USER" WITH SUPERUSER $pass ;
+		EOSQL
+		echo
+
+		echo
+		for f in /docker-entrypoint-initdb.d/*; do
+			case "$f" in
+				*.sh)  echo "$0: running $f"; . "$f" ;;
+				*.sql) echo "$0: running $f"; psql --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" < "$f" && echo ;;
+				*)     echo "$0: ignoring $f" ;;
+			esac
+			echo
+		done
+
+		su-exec postgres pg_ctl -D "$PGDATA" -m fast -w stop
+		set_listen_addresses '*'
+
+		echo
+		echo 'PostgreSQL init process complete; ready for start up.'
+		echo
+	fi
+
+	exec su-exec postgres "$@"
+fi
+
+exec "$@"