Add Dockerfile for pg_cron psql:14-alpine

2 files changed, 361 insertions, 0 deletions

diff --git a/Dockerfile b/Dockerfile
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--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,12 @@
+FROM postgres:14-alpine
+
+RUN apk add postgresql-pg_cron --repository=http://dl-cdn.alpinelinux.org/alpine/edge/community
+
+COPY docker-entrypoint.sh /usr/local/bin/
+
+RUN chmod a+x /usr/local/bin/docker-entrypoint.sh
+
+ENTRYPOINT ["docker-entrypoint.sh"]
+
+EXPOSE 5432
+CMD ["postgres"]
\ No newline at end of file
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
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+++ b/docker-entrypoint.sh
@@ -0,0 +1,349 @@
+#!/usr/bin/env bash
+set -Eeo pipefail
+# TODO swap to -Eeuo pipefail above (after handling all potentially-unset variables)
+
+# usage: file_env VAR [DEFAULT]
+#    ie: file_env 'XYZ_DB_PASSWORD' 'example'
+# (will allow for "$XYZ_DB_PASSWORD_FILE" to fill in the value of
+#  "$XYZ_DB_PASSWORD" from a file, especially for Docker's secrets feature)
+file_env() {
+	local var="$1"
+	local fileVar="${var}_FILE"
+	local def="${2:-}"
+	if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
+		echo >&2 "error: both $var and $fileVar are set (but are exclusive)"
+		exit 1
+	fi
+	local val="$def"
+	if [ "${!var:-}" ]; then
+		val="${!var}"
+	elif [ "${!fileVar:-}" ]; then
+		val="$(< "${!fileVar}")"
+	fi
+	export "$var"="$val"
+	unset "$fileVar"
+}
+
+# check to see if this file is being run or sourced from another script
+_is_sourced() {
+	# https://unix.stackexchange.com/a/215279
+	[ "${#FUNCNAME[@]}" -ge 2 ] \
+		&& [ "${FUNCNAME[0]}" = '_is_sourced' ] \
+		&& [ "${FUNCNAME[1]}" = 'source' ]
+}
+
+# used to create initial postgres directories and if run as root, ensure ownership to the "postgres" user
+docker_create_db_directories() {
+	local user; user="$(id -u)"
+
+	mkdir -p "$PGDATA"
+	# ignore failure since there are cases where we can't chmod (and PostgreSQL might fail later anyhow - it's picky about permissions of this directory)
+	chmod 700 "$PGDATA" || :
+
+	# ignore failure since it will be fine when using the image provided directory; see also https://github.com/docker-library/postgres/pull/289
+	mkdir -p /var/run/postgresql || :
+	chmod 775 /var/run/postgresql || :
+
+	# Create the transaction log directory before initdb is run so the directory is owned by the correct user
+	if [ -n "$POSTGRES_INITDB_WALDIR" ]; then
+		mkdir -p "$POSTGRES_INITDB_WALDIR"
+		if [ "$user" = '0' ]; then
+			find "$POSTGRES_INITDB_WALDIR" \! -user postgres -exec chown postgres '{}' +
+		fi
+		chmod 700 "$POSTGRES_INITDB_WALDIR"
+	fi
+
+	# allow the container to be started with `--user`
+	if [ "$user" = '0' ]; then
+		find "$PGDATA" \! -user postgres -exec chown postgres '{}' +
+		find /var/run/postgresql \! -user postgres -exec chown postgres '{}' +
+	fi
+}
+
+# initialize empty PGDATA directory with new database via 'initdb'
+# arguments to `initdb` can be passed via POSTGRES_INITDB_ARGS or as arguments to this function
+# `initdb` automatically creates the "postgres", "template0", and "template1" dbnames
+# this is also where the database user is created, specified by `POSTGRES_USER` env
+docker_init_database_dir() {
+	# "initdb" is particular about the current user existing in "/etc/passwd", so we use "nss_wrapper" to fake that if necessary
+	# see https://github.com/docker-library/postgres/pull/253, https://github.com/docker-library/postgres/issues/359, https://cwrap.org/nss_wrapper.html
+	local uid; uid="$(id -u)"
+	if ! getent passwd "$uid" &> /dev/null; then
+		# see if we can find a suitable "libnss_wrapper.so" (https://salsa.debian.org/sssd-team/nss-wrapper/-/commit/b9925a653a54e24d09d9b498a2d913729f7abb15)
+		local wrapper
+		for wrapper in {/usr,}/lib{/*,}/libnss_wrapper.so; do
+			if [ -s "$wrapper" ]; then
+				NSS_WRAPPER_PASSWD="$(mktemp)"
+				NSS_WRAPPER_GROUP="$(mktemp)"
+				export LD_PRELOAD="$wrapper" NSS_WRAPPER_PASSWD NSS_WRAPPER_GROUP
+				local gid; gid="$(id -g)"
+				echo "postgres:x:$uid:$gid:PostgreSQL:$PGDATA:/bin/false" > "$NSS_WRAPPER_PASSWD"
+				echo "postgres:x:$gid:" > "$NSS_WRAPPER_GROUP"
+				break
+			fi
+		done
+	fi
+
+	if [ -n "$POSTGRES_INITDB_WALDIR" ]; then
+		set -- --waldir "$POSTGRES_INITDB_WALDIR" "$@"
+	fi
+
+	eval 'initdb --username="$POSTGRES_USER" --pwfile=<(echo "$POSTGRES_PASSWORD") '"$POSTGRES_INITDB_ARGS"' "$@"'
+
+	# unset/cleanup "nss_wrapper" bits
+	if [ "${LD_PRELOAD:-}" = '/usr/lib/libnss_wrapper.so' ]; then
+		rm -f "$NSS_WRAPPER_PASSWD" "$NSS_WRAPPER_GROUP"
+		unset LD_PRELOAD NSS_WRAPPER_PASSWD NSS_WRAPPER_GROUP
+	fi
+}
+
+# print large warning if POSTGRES_PASSWORD is long
+# error if both POSTGRES_PASSWORD is empty and POSTGRES_HOST_AUTH_METHOD is not 'trust'
+# print large warning if POSTGRES_HOST_AUTH_METHOD is set to 'trust'
+# assumes database is not set up, ie: [ -z "$DATABASE_ALREADY_EXISTS" ]
+docker_verify_minimum_env() {
+	# check password first so we can output the warning before postgres
+	# messes it up
+	if [ "${#POSTGRES_PASSWORD}" -ge 100 ]; then
+		cat >&2 <<-'EOWARN'
+
+			WARNING: The supplied POSTGRES_PASSWORD is 100+ characters.
+
+			  This will not work if used via PGPASSWORD with "psql".
+
+			  https://www.postgresql.org/message-id/flat/E1Rqxp2-0004Qt-PL%40wrigleys.postgresql.org (BUG #6412)
+			  https://github.com/docker-library/postgres/issues/507
+
+		EOWARN
+	fi
+	if [ -z "$POSTGRES_PASSWORD" ] && [ 'trust' != "$POSTGRES_HOST_AUTH_METHOD" ]; then
+		# The - option suppresses leading tabs but *not* spaces. :)
+		cat >&2 <<-'EOE'
+			Error: Database is uninitialized and superuser password is not specified.
+			       You must specify POSTGRES_PASSWORD to a non-empty value for the
+			       superuser. For example, "-e POSTGRES_PASSWORD=password" on "docker run".
+
+			       You may also use "POSTGRES_HOST_AUTH_METHOD=trust" to allow all
+			       connections without a password. This is *not* recommended.
+
+			       See PostgreSQL documentation about "trust":
+			       https://www.postgresql.org/docs/current/auth-trust.html
+		EOE
+		exit 1
+	fi
+	if [ 'trust' = "$POSTGRES_HOST_AUTH_METHOD" ]; then
+		cat >&2 <<-'EOWARN'
+			********************************************************************************
+			WARNING: POSTGRES_HOST_AUTH_METHOD has been set to "trust". This will allow
+			         anyone with access to the Postgres port to access your database without
+			         a password, even if POSTGRES_PASSWORD is set. See PostgreSQL
+			         documentation about "trust":
+			         https://www.postgresql.org/docs/current/auth-trust.html
+			         In Docker's default configuration, this is effectively any other
+			         container on the same system.
+
+			         It is not recommended to use POSTGRES_HOST_AUTH_METHOD=trust. Replace
+			         it with "-e POSTGRES_PASSWORD=password" instead to set a password in
+			         "docker run".
+			********************************************************************************
+		EOWARN
+	fi
+}
+
+# usage: docker_process_init_files [file [file [...]]]
+#    ie: docker_process_init_files /always-initdb.d/*
+# process initializer files, based on file extensions and permissions
+docker_process_init_files() {
+	# psql here for backwards compatibility "${psql[@]}"
+	psql=( docker_process_sql )
+
+	echo
+	local f
+	for f; do
+		case "$f" in
+			*.sh)
+				# https://github.com/docker-library/postgres/issues/450#issuecomment-393167936
+				# https://github.com/docker-library/postgres/pull/452
+				if [ -x "$f" ]; then
+					echo "$0: running $f"
+					"$f"
+				else
+					echo "$0: sourcing $f"
+					. "$f"
+				fi
+				;;
+			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
+			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
+			*)        echo "$0: ignoring $f" ;;
+		esac
+		echo
+	done
+}
+
+# Execute sql script, passed via stdin (or -f flag of pqsl)
+# usage: docker_process_sql [psql-cli-args]
+#    ie: docker_process_sql --dbname=mydb <<<'INSERT ...'
+#    ie: docker_process_sql -f my-file.sql
+#    ie: docker_process_sql <my-file.sql
+docker_process_sql() {
+	local query_runner=( psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --no-password --no-psqlrc )
+	if [ -n "$POSTGRES_DB" ]; then
+		query_runner+=( --dbname "$POSTGRES_DB" )
+	fi
+
+	PGHOST= PGHOSTADDR= "${query_runner[@]}" "$@"
+}
+
+# create initial database
+# uses environment variables for input: POSTGRES_DB
+docker_setup_db() {
+	local dbAlreadyExists
+	dbAlreadyExists="$(
+		POSTGRES_DB= docker_process_sql --dbname postgres --set db="$POSTGRES_DB" --tuples-only <<-'EOSQL'
+			SELECT 1 FROM pg_database WHERE datname = :'db' ;
+		EOSQL
+	)"
+	if [ -z "$dbAlreadyExists" ]; then
+		POSTGRES_DB= docker_process_sql --dbname postgres --set db="$POSTGRES_DB" <<-'EOSQL'
+			CREATE DATABASE :"db" ;
+		EOSQL
+		echo
+	fi
+}
+
+# Loads various settings that are used elsewhere in the script
+# This should be called before any other functions
+docker_setup_env() {
+	file_env 'POSTGRES_PASSWORD'
+
+	file_env 'POSTGRES_USER' 'postgres'
+	file_env 'POSTGRES_DB' "$POSTGRES_USER"
+	file_env 'POSTGRES_INITDB_ARGS'
+	: "${POSTGRES_HOST_AUTH_METHOD:=}"
+
+	declare -g DATABASE_ALREADY_EXISTS
+	# look specifically for PG_VERSION, as it is expected in the DB dir
+	if [ -s "$PGDATA/PG_VERSION" ]; then
+		DATABASE_ALREADY_EXISTS='true'
+	fi
+}
+
+# append POSTGRES_HOST_AUTH_METHOD to pg_hba.conf for "host" connections
+# all arguments will be passed along as arguments to `postgres` for getting the value of 'password_encryption'
+pg_setup_hba_conf() {
+	# default authentication method is md5 on versions before 14
+	# https://www.postgresql.org/about/news/postgresql-14-released-2318/
+	if [ "$1" = 'postgres' ]; then
+		shift
+	fi
+	local auth
+	# check the default/configured encryption and use that as the auth method
+	auth="$(postgres -C password_encryption "$@")"
+	# postgres 9 only reports "on" and not "md5"
+	if [ "$auth" = 'on' ]; then
+		auth='md5'
+	fi
+	: "${POSTGRES_HOST_AUTH_METHOD:=$auth}"
+	{
+		echo
+		if [ 'trust' = "$POSTGRES_HOST_AUTH_METHOD" ]; then
+			echo '# warning trust is enabled for all connections'
+			echo '# see https://www.postgresql.org/docs/12/auth-trust.html'
+		fi
+		echo "host all all all $POSTGRES_HOST_AUTH_METHOD"
+	} >> "$PGDATA/pg_hba.conf"
+}
+
+# start socket-only postgresql server for setting up or running scripts
+# all arguments will be passed along as arguments to `postgres` (via pg_ctl)
+docker_temp_server_start() {
+	if [ "$1" = 'postgres' ]; then
+		shift
+	fi
+
+	# internal start of server in order to allow setup using psql client
+	# does not listen on external TCP/IP and waits until start finishes
+	set -- "$@" -c listen_addresses='' -p "${PGPORT:-5432}"
+
+	PGUSER="${PGUSER:-$POSTGRES_USER}" \
+	pg_ctl -D "$PGDATA" \
+		-o "$(printf '%q ' "$@")" \
+		-w start
+}
+
+# stop postgresql server after done setting up user and running scripts
+docker_temp_server_stop() {
+	PGUSER="${PGUSER:-postgres}" \
+	pg_ctl -D "$PGDATA" -m fast -w stop
+}
+
+# check arguments for an option that would cause postgres to stop
+# return true if there is one
+_pg_want_help() {
+	local arg
+	for arg; do
+		case "$arg" in
+			# postgres --help | grep 'then exit'
+			# leaving out -C on purpose since it always fails and is unhelpful:
+			# postgres: could not access the server configuration file "/var/lib/postgresql/data/postgresql.conf": No such file or directory
+			-'?'|--help|--describe-config|-V|--version)
+				return 0
+				;;
+		esac
+	done
+	return 1
+}
+
+_main() {
+	# if first arg looks like a flag, assume we want to run postgres server
+	if [ "${1:0:1}" = '-' ]; then
+		set -- postgres "$@"
+	fi
+
+	if [ "$1" = 'postgres' ] && ! _pg_want_help "$@"; then
+		docker_setup_env
+		# setup data directories and permissions (when run as root)
+		docker_create_db_directories
+		if [ "$(id -u)" = '0' ]; then
+			# then restart script as postgres user
+			exec su-exec postgres "$BASH_SOURCE" "$@"
+		fi
+
+		# only run initialization on an empty data directory
+		if [ -z "$DATABASE_ALREADY_EXISTS" ]; then
+			docker_verify_minimum_env
+
+			# check dir permissions to reduce likelihood of half-initialized database
+			ls /docker-entrypoint-initdb.d/ > /dev/null
+
+			docker_init_database_dir
+			pg_setup_hba_conf "$@"
+
+			# PGPASSWORD is required for psql when authentication is required for 'local' connections via pg_hba.conf and is otherwise harmless
+			# e.g. when '--auth=md5' or '--auth-local=md5' is used in POSTGRES_INITDB_ARGS
+			export PGPASSWORD="${PGPASSWORD:-$POSTGRES_PASSWORD}"
+			docker_temp_server_start "$@"
+
+			docker_setup_db
+			docker_process_init_files /docker-entrypoint-initdb.d/*
+
+			docker_temp_server_stop
+			unset PGPASSWORD
+
+			echo
+			echo 'PostgreSQL init process complete; ready for start up.'
+			echo
+		else
+			echo
+			echo 'PostgreSQL Database directory appears to contain a database; Skipping initialization'
+			echo
+		fi
+	fi
+
+	exec "$@"
+}
+
+if ! _is_sourced; then
+	_main "$@"
+fi
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