#!/bin/sh
#
# postgresql-setup    Initialization and upgrade operations for PostgreSQL
#
# Installed as /usr/pgsql-x.y/bin/postgresqlxy-setup
#

# PGVERSION is the full package version, e.g., 9.4.0
# Note: the specfile inserts the correct value during package build
PGVERSION=__RPM_PGVERSION__
# PGMAJORVERSION is major version, e.g., 9.4 (this should match PG_VERSION)
PGMAJORVERSION=__RPM_PGMAJORVERSION__
# PGENGINE is the directory containing the postmaster executable
# Note: the specfile inserts the correct value during package build
PGENGINE=__RPM_PGENGINE__
# PREVMAJORVERSION is the previous major version, e.g., 9.1; it's the default
# target for pg_upgrade if not overridden.
PREVMAJORVERSION=__RPM_PREVMAJORVERSION__
# systemd unit name
PGUNITNAME=__RPM_UNITNAME__
# Package name; used in help messages
PGPACKAGENAME=__RPM_PACKAGENAME__

# The second parameter is the new database version, i.e. $PGMAJORVERSION in this case.
# Use  the unit name from the rpm build, if not specified.
SERVICE_NAME="${2:-$PGUNITNAME}"

# The third parameter is the old database service control file name sans any
# .service suffix, e.g postgresql-9.3 in this case.  Use
# "postgresql-$PREVMAJORVERSION" service, if not specified.
OLD_SERVICE_NAME="${3:-postgresql-$PREVMAJORVERSION}"

# Was this RPM built with systemd or sysvinit?
USING_SYSTEMD=__RPM_SYSTEMD__

# Find the unit file for new version.
if [ -f "/etc/systemd/system/${SERVICE_NAME}.service" ]
then
    SERVICE_FILE="/etc/systemd/system/${SERVICE_NAME}.service"
elif [ -f "/lib/systemd/system/${SERVICE_NAME}.service" ]
then
    SERVICE_FILE="/lib/systemd/system/${SERVICE_NAME}.service"
else
    echo "Could not find systemd unit file ${SERVICE_NAME}.service"
    exit 1
fi

# Get port number and data directory from the service file
PGPORT=$(gawk -F '=' '/^Environment=PGPORT=/ { print $3}' "${SERVICE_FILE}")
PGDATA=$(gawk -F '=' '/^Environment=PGDATA=/ { print $3}' "${SERVICE_FILE}")
PGSERVERUSER=$(awk -F '=' '/^User=/ { print $2}' "${SERVICE_FILE}")
PGSERVERGROUP=$(awk -F '=' '/^Group=/ { print $2}' "${SERVICE_FILE}")

# Log files for initdb and pg_upgrade are placed in the parent dir of the
# datadir. On a default install that's /var/lib/pgsql/$MAJORVERSION .
PGINITDBLOG="$(dirname $PGDATA)/initdb.log"

export PGPORT
export PGDATA

# For SELinux we need to use 'runuser' not 'su'
if [ -x /sbin/runuser ]
then
    SU=runuser
else
    SU=su
fi


script_result=0

# code shared between initdb and upgrade actions
perform_initdb(){
    if [ ! -e "$PGDATA" -a ! -h "$PGDATA" ]
    then
        mkdir -p "$PGDATA" || return 1
        chown $PGSERVERUSER:$PGSERVERGROUP "$PGDATA"
        chmod go-rwx "$PGDATA"
    fi
    # Clean up SELinux tagging for PGDATA
    [ -x /sbin/restorecon ] && /sbin/restorecon "$PGDATA"

    # Create the initdb log file if needed
    if [ ! -e "$PGINITDBLOG" -a ! -h "$PGINITDBLOG" ]
    then
        touch "$PGINITDBLOG" || return 1
        chown $PGSERVERUSER:$PGSERVERGROUP "$PGINITDBLOG"
        chmod go-rwx "$PGINITDBLOG"
        [ -x /sbin/restorecon ] && /sbin/restorecon "$PGINITDBLOG"
    fi

    # Initialize the database
    $SU -l postgres -c "$PGENGINE/initdb --pgdata='$PGDATA' --auth='ident'" >> "$PGINITDBLOG" 2>&1 < /dev/null

    # Create directory for postmaster log files
    mkdir "$PGDATA/pg_log"
    chown $PGSERVERUSER:$PGSERVERGROUP "$PGDATA/pg_log"
    chmod go-rwx "$PGDATA/pg_log"

    if [ -f "$PGDATA/PG_VERSION" ]
    then
        return 0
    fi
    echo 1>&2 "ERROR: $PGDATA/PG_VERSION not found after initdb; check logs for details."
    return 1
}

initdb(){
    if [ -f "$PGDATA/PG_VERSION" ]
    then
        echo $"Data directory is not empty!"
        echo
        script_result=1
    else
        echo -n $"Initializing database ... "
        if perform_initdb
        then
            echo $"OK"
        else
            echo $"failed, see $PGINITDBLOG"
            script_result=1
        fi
        echo
    fi
}

upgrade(){
    PGUPLOG="$(dirname $PGDATA)/pgupgrade.log"

    ## Absorb configuration settings from the specified systemd service files.

    # Figure out what version we're upgrading from using the control file name
    # if we can.
    OLDMAJORVERSION=$(echo "$OLD_SERVICE_NAME" | gawk 'match($0, "postgresql-([0-9]+)\\.([0-9]+)\\.service", matches) { printf "%d.%d",matches[1],matches[2]; }' )
    if [ -z "$OLDMAJORVERSION" ]; then
        echo 2>&1 "Failed to determine major version from service file name $OLD_SERVICE_NAME"
        echo 2>&1 "You will need to run pg_upgrade manually instead."
        exit 1
    fi

    # Find the old Pg version's control file
    if [ -f "/etc/systemd/system/${OLD_SERVICE_NAME}.service" ]
    then
        OLD_SERVICE_FILE="/etc/systemd/system/${OLD_SERVICE_NAME}.service"
    elif [ -f "/lib/systemd/system/${OLD_SERVICE_NAME}.service" ]
    then
        OLD_SERVICE_FILE="/lib/systemd/system/${OLD_SERVICE_NAME}.service"
    else
        echo "Could not find systemd unit file ${OLD_SERVICE_NAME}.service"
        exit 1
    fi

    ## Get port number and data directory from the service file
    NEWPGPORT=$PGPORT
    NEWPGDATA=$PGDATA

    ## Get port number and data directory for old serverfrom the service file
    OLDPGPORT=$(gawk -F '=' '/^Environment=PGPORT=/ { print $3}' "${OLD_SERVICE_FILE}")
    OLDPGDATA=$(gawk -F '=' '/^Environment=PGDATA=/ { print $3}' "${OLD_SERVICE_FILE}")

    # OLDPGENGINE is the directory containing the previous postmaster executable
    # We can determine it reliably by examining the binary paths in the control file
    OLDPGENGINE=$(dirname $(awk -F '[= ]' '/^ExecStart=/ { print $2}' "${OLD_SERVICE_FILE}" ) )

    # must see previous version in PG_VERSION
    if [ ! -f "$OLDPGDATA/PG_VERSION" -o x`cat "$OLDPGDATA/PG_VERSION"` != x"$OLDMAJORVERSION" ]
    then
        echo
        echo $"Cannot upgrade because database in $OLDPGDATA is missing or not of expected version $OLDMAJORVERSION."
        echo
        exit 1
    fi

    if [ ! -x "$PGENGINE/pg_upgrade" ]
    then
        echo
        echo $"pg_upgrade not found for $PGMAJORVERSION. Please install the ${PGPACKAGENAME}-contrib RPM."
        echo
        exit 5
    fi

    # Perform initdb on the new server
    $PGENGINE/postgresql${PGMAJORVERSION/.}-setup initdb
    RETVAL=$?
    if [ $RETVAL -ne 0 ]
    then
        echo "Failed to initdb new datadir for $PGMAJORVERSION; see $PGINITDBLOG for details"
        exit 1
    fi

    # Check the clusters first, without changing any data:
    $RUNUSER -l postgres -c "$PGENGINE/pg_upgrade -b $OLDPGENGINE -B $PGENGINE/ -d $OLDPGDATA -D $NEWPGDATA -p $OLDPGPORT -P $NEWPGPORT -c"
    RETVAL=$?
    if [ $RETVAL -eq 0 ]
    then
        echo "Clusters checked successfully, proceeding with upgrade from $OLDMAJORVERSION to $PGMAJORVERSION"
        echo "Stopping old cluster"
        if [ "$USING_SYSTEMD" = 1 ]
        then
            /bin/systemctl stop $OLD_SERVICE_NAME.service
        else
            service $OLD_SERVICE_NAME stop
        fi

        # Set up log file for pg_upgrade
        rm -f "$PGUPLOG"
        touch "$PGUPLOG" || exit 1
        chown $PGSERVERUSER:$PGSERVERGROUP "$PGUPLOG"
        chmod go-rwx "$PGUPLOG"
        [ -x /sbin/restorecon ] && /sbin/restorecon "$PGUPLOG"

        echo "Performing upgrade"
        $RUNUSER -l postgres -c "$PGENGINE/pg_upgrade \
            -b $OLDPGENGINE -B $PGENGINE/ \
            -d $OLDPGDATA -D $NEWPGDATA -p $OLDPGPORT -P $NEWPGPORT" >> "$PGUPLOG" 2>&1 < /dev/null
    else
        echo "Cluster check failed. Please see the output above."
        exit 1
    fi
        echo

    exit 0
}

# See how we were called.
case "$1" in
  initdb)
    initdb
    ;;
  upgrade)
    upgrade
    ;;
  *)
    echo $"Usage: $0 {initdb|upgrade} [ service_name ]"
    exit 2
esac

exit $script_result