#!/usr/bin/bash

# Automatically create systemd unit for PostgreSQL service.

set -e


. "/usr/share/postgresql-setup/library.sh"

USAGE_STRING=$"\
Usage: $0 --unit SYSTEMD_UNIT --datadir DATADIR

Automatically create systemd unit for PostgreSQL service.

For more info and howto/when use this script please look at the documentation
file /usr/share/doc/postgresql/README.rpm-dist.

Options:
  --unit=UNIT_NAME           The name of new systemdunit, of form
                             postgresql@<string>, will generate service file
                             postgresql@<string>.service.
  --datadir=DATADIR          Where the data will be stored.  The postgres
                             user needs to have permissions to create this
                             directory.
"

root_prereq

opt_unit=default
opt_datadir=default

test $# -ne 0 || {
    echo >&2 "$USAGE_STRING"
    exit 1
}

args=$(getopt -o "" -l "datadir:,unit:,help,version" -n "$0" -- "$@") || exit 1
eval set -- "$args"

while true; do
    case "$1" in
    --datadir|--unit)
        opt=${1##--}
        opt=${opt##-}
        opt=${opt//-/_}
        eval "opt_$opt=\$2"
        shift 2
        ;;

    --help)
        echo "$USAGE_STRING"
        exit 0
        ;;

    --version)
        echo "postgresql-new-systemd-unit 8.6"
        echo $"Built against PostgreSQL version 13.18."
        exit 0
        ;;

    --) # end!
        shift
        break
        ;;

    *)
        echo "programmer mistake ($1)" >&2
        exit 1
        ;;
    esac
done


required_ok=:
for opt in unit datadir; do
    if eval "test \"\$opt_$opt\" == default"; then
        required_ok=false
        error "option --$opt required"
    fi
done
$required_ok || die "missing argument"

case $opt_unit in *.service) opt_unit=${opt_unit%%.service} ;; esac
case $opt_unit in
    postgresql@*) ;;
    *) die "the --unit needs to start with 'postgresql@', e.g. 'postgresql@second'" ;;
esac

exit_handler()
{
    test -z "$cleanup_dropin" || {
        info "cleaning up created dropin directory"
        eval "$cleanup_dropin"
    }
}
cleanup_dropin=
trap exit_handler 0

dropindir="/etc/systemd/system/$opt_unit.service.d"
dropin="$dropindir/30-postgresql-setup.conf"

test ! -e "$dropindir" \
    || die "The systemd drop-in directory '$dropindir' already exists"

mkdir -p "$dropindir" \
    || die "Can not create '$dropindir'"

cleanup_dropin="rm -rf \"$dropindir\""

generate_dropin ()
{
cat <<EOF > "$1"
[Service]
Environment=PGDATA=$opt_datadir
EOF
}

generate_dropin "$dropin" || die "Can not write to '$dropin'"

reload_systemd="systemctl daemon-reload"
$reload_systemd || die $"Can not perform '$reload_systemd'"

parentdir=$(dirname "$opt_datadir")
if ! /usr/sbin/runuser -s /bin/sh -l postgres -c "test -w $(printf %q "$parentdir")"; then
    error   "The '$parentdir' directory doesn't exit or 'postgres' can not"
    error_q "write there.  Please either fix the permissions or change the"
    error_q "configuration in dropin directory before trying again."
    exit 1
fi

info $"The '$opt_unit.service' configured in '$dropindir' directory."
cleanup_dropin=