From 779b7123f125b51a9b04ccc36fb25bbdd9a9725d Mon Sep 17 00:00:00 2001
From: Marius Bezuidenhout <marius.bezuidenhout@gmail.com>
Date: Wed, 16 Jul 2025 12:51:35 +0200
Subject: [PATCH 1/2] Added functionality to choose another user than
 'postgres'

---
 13-to-14/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 13-to-15/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 13-to-16/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 13-to-17/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 14-to-15/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 14-to-16/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 14-to-17/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 15-to-16/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 15-to-17/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 16-to-17/docker-upgrade | 38 +++++++++++++++++++++++++++++++++++---
 docker-upgrade          | 38 +++++++++++++++++++++++++++++++++++---
 11 files changed, 385 insertions(+), 33 deletions(-)

diff --git a/13-to-14/docker-upgrade b/13-to-14/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/13-to-14/docker-upgrade
+++ b/13-to-14/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/13-to-15/docker-upgrade b/13-to-15/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/13-to-15/docker-upgrade
+++ b/13-to-15/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/13-to-16/docker-upgrade b/13-to-16/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/13-to-16/docker-upgrade
+++ b/13-to-16/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/13-to-17/docker-upgrade b/13-to-17/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/13-to-17/docker-upgrade
+++ b/13-to-17/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/14-to-15/docker-upgrade b/14-to-15/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/14-to-15/docker-upgrade
+++ b/14-to-15/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/14-to-16/docker-upgrade b/14-to-16/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/14-to-16/docker-upgrade
+++ b/14-to-16/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/14-to-17/docker-upgrade b/14-to-17/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/14-to-17/docker-upgrade
+++ b/14-to-17/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/15-to-16/docker-upgrade b/15-to-16/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/15-to-16/docker-upgrade
+++ b/15-to-16/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/15-to-17/docker-upgrade b/15-to-17/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/15-to-17/docker-upgrade
+++ b/15-to-17/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/16-to-17/docker-upgrade b/16-to-17/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/16-to-17/docker-upgrade
+++ b/16-to-17/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then
diff --git a/docker-upgrade b/docker-upgrade
index c8c0699..ad27fe3 100755
--- a/docker-upgrade
+++ b/docker-upgrade
@@ -1,6 +1,34 @@
 #!/bin/bash
 set -e
 
+if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
+	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
+	exit 1
+fi
+
+if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
+	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
+	exit 1
+fi
+
+if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
+	PGGID="$PGUID"
+fi
+
+: "${PGUSER:=postgres}"
+
+if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
+    echo "Creating group '$PGUSER' with GID $PGGID..."
+    addgroup --system --gid "$PGGID" "$PGUSER"
+    echo "Group created."
+fi
+
+if [[ -z "$(getent passwd "$PGUSER")" ]]; then
+	echo "User '$PGUSER' does not exist. Creating..."
+	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
+	echo "User '$PGUSER' created."
+fi
+
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -8,9 +36,13 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown postgres .
-	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
-	exec gosu postgres "$BASH_SOURCE" "$@"
+	chown "$PGUSER" .
+	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
+	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+fi
+
+if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+    POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
 if [ "$1" = 'pg_upgrade' ]; then

From c5a6c213dc0200c8a46c0f4aaaf5dcdd131f5378 Mon Sep 17 00:00:00 2001
From: Marius Bezuidenhout <marius.bezuidenhout@gmail.com>
Date: Wed, 16 Jul 2025 13:35:42 +0200
Subject: [PATCH 2/2] Adding PGUSER to initdb command if not set.

---
 13-to-14/Dockerfile     |  8 ++++----
 13-to-14/docker-upgrade | 36 ++++--------------------------------
 13-to-15/Dockerfile     |  8 ++++----
 13-to-15/docker-upgrade | 36 ++++--------------------------------
 13-to-16/Dockerfile     |  8 ++++----
 13-to-16/docker-upgrade | 36 ++++--------------------------------
 13-to-17/Dockerfile     |  8 ++++----
 13-to-17/docker-upgrade | 36 ++++--------------------------------
 14-to-15/Dockerfile     |  8 ++++----
 14-to-15/docker-upgrade | 36 ++++--------------------------------
 14-to-16/Dockerfile     |  8 ++++----
 14-to-16/docker-upgrade | 36 ++++--------------------------------
 14-to-17/Dockerfile     |  8 ++++----
 14-to-17/docker-upgrade | 36 ++++--------------------------------
 15-to-16/Dockerfile     |  8 ++++----
 15-to-16/docker-upgrade | 36 ++++--------------------------------
 15-to-17/Dockerfile     |  8 ++++----
 15-to-17/docker-upgrade | 36 ++++--------------------------------
 16-to-17/Dockerfile     |  8 ++++----
 16-to-17/docker-upgrade | 36 ++++--------------------------------
 Dockerfile.template     |  8 ++++----
 docker-upgrade          | 36 ++++--------------------------------
 22 files changed, 88 insertions(+), 396 deletions(-)

diff --git a/13-to-14/Dockerfile b/13-to-14/Dockerfile
index 8e907ce..928f50e 100644
--- a/13-to-14/Dockerfile
+++ b/13-to-14/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/13/bin
-ENV PGBINNEW /usr/lib/postgresql/14/bin
+ENV PGBINOLD=/usr/lib/postgresql/13/bin
+ENV PGBINNEW=/usr/lib/postgresql/14/bin
 
-ENV PGDATAOLD /var/lib/postgresql/13/data
-ENV PGDATANEW /var/lib/postgresql/14/data
+ENV PGDATAOLD=/var/lib/postgresql/13/data
+ENV PGDATANEW=/var/lib/postgresql/14/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/13-to-14/docker-upgrade b/13-to-14/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/13-to-14/docker-upgrade
+++ b/13-to-14/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/13-to-15/Dockerfile b/13-to-15/Dockerfile
index c0da60e..369ee7f 100644
--- a/13-to-15/Dockerfile
+++ b/13-to-15/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/13/bin
-ENV PGBINNEW /usr/lib/postgresql/15/bin
+ENV PGBINOLD=/usr/lib/postgresql/13/bin
+ENV PGBINNEW=/usr/lib/postgresql/15/bin
 
-ENV PGDATAOLD /var/lib/postgresql/13/data
-ENV PGDATANEW /var/lib/postgresql/15/data
+ENV PGDATAOLD=/var/lib/postgresql/13/data
+ENV PGDATANEW=/var/lib/postgresql/15/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/13-to-15/docker-upgrade b/13-to-15/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/13-to-15/docker-upgrade
+++ b/13-to-15/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/13-to-16/Dockerfile b/13-to-16/Dockerfile
index 444b8e3..3d65e02 100644
--- a/13-to-16/Dockerfile
+++ b/13-to-16/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/13/bin
-ENV PGBINNEW /usr/lib/postgresql/16/bin
+ENV PGBINOLD=/usr/lib/postgresql/13/bin
+ENV PGBINNEW=/usr/lib/postgresql/16/bin
 
-ENV PGDATAOLD /var/lib/postgresql/13/data
-ENV PGDATANEW /var/lib/postgresql/16/data
+ENV PGDATAOLD=/var/lib/postgresql/13/data
+ENV PGDATANEW=/var/lib/postgresql/16/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/13-to-16/docker-upgrade b/13-to-16/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/13-to-16/docker-upgrade
+++ b/13-to-16/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/13-to-17/Dockerfile b/13-to-17/Dockerfile
index 145d1da..52774ff 100644
--- a/13-to-17/Dockerfile
+++ b/13-to-17/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/13/bin
-ENV PGBINNEW /usr/lib/postgresql/17/bin
+ENV PGBINOLD=/usr/lib/postgresql/13/bin
+ENV PGBINNEW=/usr/lib/postgresql/17/bin
 
-ENV PGDATAOLD /var/lib/postgresql/13/data
-ENV PGDATANEW /var/lib/postgresql/17/data
+ENV PGDATAOLD=/var/lib/postgresql/13/data
+ENV PGDATANEW=/var/lib/postgresql/17/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/13-to-17/docker-upgrade b/13-to-17/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/13-to-17/docker-upgrade
+++ b/13-to-17/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/14-to-15/Dockerfile b/14-to-15/Dockerfile
index cf370ee..4b323b2 100644
--- a/14-to-15/Dockerfile
+++ b/14-to-15/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/14/bin
-ENV PGBINNEW /usr/lib/postgresql/15/bin
+ENV PGBINOLD=/usr/lib/postgresql/14/bin
+ENV PGBINNEW=/usr/lib/postgresql/15/bin
 
-ENV PGDATAOLD /var/lib/postgresql/14/data
-ENV PGDATANEW /var/lib/postgresql/15/data
+ENV PGDATAOLD=/var/lib/postgresql/14/data
+ENV PGDATANEW=/var/lib/postgresql/15/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/14-to-15/docker-upgrade b/14-to-15/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/14-to-15/docker-upgrade
+++ b/14-to-15/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/14-to-16/Dockerfile b/14-to-16/Dockerfile
index 72ce29d..5bd0f89 100644
--- a/14-to-16/Dockerfile
+++ b/14-to-16/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/14/bin
-ENV PGBINNEW /usr/lib/postgresql/16/bin
+ENV PGBINOLD=/usr/lib/postgresql/14/bin
+ENV PGBINNEW=/usr/lib/postgresql/16/bin
 
-ENV PGDATAOLD /var/lib/postgresql/14/data
-ENV PGDATANEW /var/lib/postgresql/16/data
+ENV PGDATAOLD=/var/lib/postgresql/14/data
+ENV PGDATANEW=/var/lib/postgresql/16/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/14-to-16/docker-upgrade b/14-to-16/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/14-to-16/docker-upgrade
+++ b/14-to-16/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/14-to-17/Dockerfile b/14-to-17/Dockerfile
index 2cec8e9..1e8d53d 100644
--- a/14-to-17/Dockerfile
+++ b/14-to-17/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/14/bin
-ENV PGBINNEW /usr/lib/postgresql/17/bin
+ENV PGBINOLD=/usr/lib/postgresql/14/bin
+ENV PGBINNEW=/usr/lib/postgresql/17/bin
 
-ENV PGDATAOLD /var/lib/postgresql/14/data
-ENV PGDATANEW /var/lib/postgresql/17/data
+ENV PGDATAOLD=/var/lib/postgresql/14/data
+ENV PGDATANEW=/var/lib/postgresql/17/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/14-to-17/docker-upgrade b/14-to-17/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/14-to-17/docker-upgrade
+++ b/14-to-17/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/15-to-16/Dockerfile b/15-to-16/Dockerfile
index 22b5a39..22fc47d 100644
--- a/15-to-16/Dockerfile
+++ b/15-to-16/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/15/bin
-ENV PGBINNEW /usr/lib/postgresql/16/bin
+ENV PGBINOLD=/usr/lib/postgresql/15/bin
+ENV PGBINNEW=/usr/lib/postgresql/16/bin
 
-ENV PGDATAOLD /var/lib/postgresql/15/data
-ENV PGDATANEW /var/lib/postgresql/16/data
+ENV PGDATAOLD=/var/lib/postgresql/15/data
+ENV PGDATANEW=/var/lib/postgresql/16/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/15-to-16/docker-upgrade b/15-to-16/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/15-to-16/docker-upgrade
+++ b/15-to-16/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/15-to-17/Dockerfile b/15-to-17/Dockerfile
index 10ef8ff..1cf4e1f 100644
--- a/15-to-17/Dockerfile
+++ b/15-to-17/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/15/bin
-ENV PGBINNEW /usr/lib/postgresql/17/bin
+ENV PGBINOLD=/usr/lib/postgresql/15/bin
+ENV PGBINNEW=/usr/lib/postgresql/17/bin
 
-ENV PGDATAOLD /var/lib/postgresql/15/data
-ENV PGDATANEW /var/lib/postgresql/17/data
+ENV PGDATAOLD=/var/lib/postgresql/15/data
+ENV PGDATANEW=/var/lib/postgresql/17/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/15-to-17/docker-upgrade b/15-to-17/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/15-to-17/docker-upgrade
+++ b/15-to-17/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/16-to-17/Dockerfile b/16-to-17/Dockerfile
index fcf5c9b..07a965b 100644
--- a/16-to-17/Dockerfile
+++ b/16-to-17/Dockerfile
@@ -15,11 +15,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/16/bin
-ENV PGBINNEW /usr/lib/postgresql/17/bin
+ENV PGBINOLD=/usr/lib/postgresql/16/bin
+ENV PGBINNEW=/usr/lib/postgresql/17/bin
 
-ENV PGDATAOLD /var/lib/postgresql/16/data
-ENV PGDATANEW /var/lib/postgresql/17/data
+ENV PGDATAOLD=/var/lib/postgresql/16/data
+ENV PGDATANEW=/var/lib/postgresql/17/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/16-to-17/docker-upgrade b/16-to-17/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/16-to-17/docker-upgrade
+++ b/16-to-17/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi
 
diff --git a/Dockerfile.template b/Dockerfile.template
index 287e789..09b1fa6 100644
--- a/Dockerfile.template
+++ b/Dockerfile.template
@@ -9,11 +9,11 @@ RUN set -eux; \
 	; \
 	rm -rf /var/lib/apt/lists/*
 
-ENV PGBINOLD /usr/lib/postgresql/{{ .old }}/bin
-ENV PGBINNEW /usr/lib/postgresql/{{ .new }}/bin
+ENV PGBINOLD=/usr/lib/postgresql/{{ .old }}/bin
+ENV PGBINNEW=/usr/lib/postgresql/{{ .new }}/bin
 
-ENV PGDATAOLD /var/lib/postgresql/{{ .old }}/data
-ENV PGDATANEW /var/lib/postgresql/{{ .new }}/data
+ENV PGDATAOLD=/var/lib/postgresql/{{ .old }}/data
+ENV PGDATANEW=/var/lib/postgresql/{{ .new }}/data
 
 RUN set -eux; \
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"; \
diff --git a/docker-upgrade b/docker-upgrade
index ad27fe3..509f4c7 100755
--- a/docker-upgrade
+++ b/docker-upgrade
@@ -1,34 +1,6 @@
 #!/bin/bash
 set -e
 
-if [[ -n "$PGUSER" && -z "$PGUID" ]]; then
-	echo "Error: PGUSER is set to '$PGUSER' but PGUID is not set." >&2
-	exit 1
-fi
-
-if [[ ! "$PGUID" =~ ^[0-9]+$ ]]; then
-	echo "Error: PGUID must be an integer. Current value: '$PGUID'" >&2
-	exit 1
-fi
-
-if [[ -n "$PGUSER" && -z "$PGGID" ]]; then
-	PGGID="$PGUID"
-fi
-
-: "${PGUSER:=postgres}"
-
-if [[ -n "$PGGID" && -z "$(getent group "$PGGID")" ]]; then
-    echo "Creating group '$PGUSER' with GID $PGGID..."
-    addgroup --system --gid "$PGGID" "$PGUSER"
-    echo "Group created."
-fi
-
-if [[ -z "$(getent passwd "$PGUSER")" ]]; then
-	echo "User '$PGUSER' does not exist. Creating..."
-	adduser --system --no-create-home --uid "$PGUID" --gid "$PGGID" --home /var/lib/postgresql --disabled-password "$PGUSER"
-	echo "User '$PGUSER' created."
-fi
-
 if [ "$#" -eq 0 -o "${1:0:1}" = '-' ]; then
 	set -- pg_upgrade "$@"
 fi
@@ -36,12 +8,12 @@ fi
 if [ "$1" = 'pg_upgrade' -a "$(id -u)" = '0' ]; then
 	mkdir -p "$PGDATAOLD" "$PGDATANEW"
 	chmod 700 "$PGDATAOLD" "$PGDATANEW"
-	chown "$PGUSER" .
-	chown -R "$PGUSER" "$PGDATAOLD" "$PGDATANEW"
-	exec gosu "$PGUSER" "$BASH_SOURCE" "$@"
+	chown postgres .
+	chown -R postgres "$PGDATAOLD" "$PGDATANEW"
+	exec gosu postgres "$BASH_SOURCE" "$@"
 fi
 
-if [[ ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
+if [[ -n "$PGUSER" && ! "$POSTGRES_INITDB_ARGS" =~ ((--username=|-U[[:space:]])) ]]; then
     POSTGRES_INITDB_ARGS+=" --username=$PGUSER"
 fi