#!/bin/sh

for BINARY in redis-server redis-sentinel
do
	for MODE in default templated
	do
		case "${BINARY}" in
		redis-server)
			NAME="redis"
			;;
		redis-sentinel)
			NAME="sentinel"
			;;
		esac

		case "${MODE}" in
		default)
			EXTRA="Alias=${NAME}.service"
			TARGET="debian/${BINARY}.service"
			NAMESPACED="${NAME}"
			DESCRIPTION="Advanced key-value store"
			;;
		templated)
			EXTRA=""
			TARGET="debian/${BINARY}@.service"
			NAMESPACED="${NAME}-%i"
			DESCRIPTION="Advanced key-value store (%I)"
			;;
		esac

		: >${TARGET}

		if [ "${MODE}" = "templated" ]
		then
			cat >> ${TARGET} <<EOF
# Templated service file for ${BINARY}(1)
#
# Each instance of ${BINARY} requires its own configuration file:
#
#   $ cp /etc/redis/${NAME}.conf /etc/redis/${NAME}-myname.conf
#   $ chown redis:redis /etc/redis/${NAME}-myname.conf
#
# Ensure each instance is using their own database:
#
#   $ sed -i -e 's@^dbfilename .*@dbfilename dump-myname.rdb@' /etc/redis/${NAME}-myname.conf
#
# We then listen exlusively on UNIX sockets to avoid TCP port collisions:
#
#   $ sed -i -e 's@^port .*@port 0@' /etc/redis/${NAME}-myname.conf
#   $ sed -i -e 's@^\\(# \\)\\{0,1\\}unixsocket .*@unixsocket /run/${NAME}-myname/${BINARY}.sock@' /etc/redis/${NAME}-myname.conf
#
# ... and ensure we are logging, etc. in a unique location:
#
#   $ sed -i -e 's@^logfile .*@logfile /var/log/redis/${BINARY}-myname.log@' /etc/redis/${NAME}-myname.conf
#   $ sed -i -e 's@^pidfile .*@pidfile /run/redis-myname/${BINARY}.pid@' /etc/redis/${NAME}-myname.conf
#
# We can then start the service as follows, validating we are using our own
# configuration:
#
#   $ systemctl start ${BINARY}@myname.service
#   $ redis-cli -s /run/${NAME}-myname/${BINARY}.sock info | grep config_file
#
#  -- Chris Lamb <lamby@debian.org>  Mon, 09 Oct 2017 22:17:24 +0100
EOF
		fi

		cat >> ${TARGET} <<EOF
[Unit]
Description=${DESCRIPTION}
After=network.target
Documentation=http://redis.io/documentation, man:${BINARY}(1)

[Service]
Type=notify
ExecStart=/usr/bin/${BINARY} /etc/redis/${NAMESPACED}.conf --supervised systemd --daemonize no
PIDFile=/run/${NAMESPACED}/${BINARY}.pid
TimeoutStopSec=0
Restart=always
User=redis
Group=redis
RuntimeDirectory=${NAMESPACED}
RuntimeDirectoryMode=2755

UMask=007
PrivateTmp=true
LimitNOFILE=65535
PrivateDevices=true
ProtectHome=true
ProtectSystem=strict
ReadWritePaths=-/var/lib/redis
ReadWritePaths=-/var/log/redis
ReadWritePaths=-/var/run/${NAMESPACED}

CapabilityBoundingSet=
LockPersonality=true
MemoryDenyWriteExecute=true
NoNewPrivileges=true
PrivateUsers=true
ProtectClock=true
ProtectControlGroups=true
ProtectHostname=true
ProtectKernelLogs=true
ProtectKernelModules=true
ProtectKernelTunables=true
ProtectProc=invisible
RemoveIPC=true
RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX
RestrictNamespaces=true
RestrictRealtime=true
RestrictSUIDSGID=true
SystemCallArchitectures=native
SystemCallFilter=@system-service
SystemCallFilter=~ @privileged @resources

# ${BINARY} can write to its own config file when in cluster mode so we
# permit writing there by default. If you are not using this feature, it is
# recommended that you remove this line.
ReadWriteDirectories=-/etc/redis

# This restricts this service from executing binaries other than ${BINARY}
# itself. This is really effective at e.g. making it impossible to an
# attacker to spawn a shell on the system, but might be more restrictive
# than desired. If you need to, you can permit the execution of extra
# binaries by adding an extra ExecPaths= directive with the command
# systemctl edit ${BINARY}.service
NoExecPaths=/
ExecPaths=/usr/bin/${BINARY} /usr/lib /lib

[Install]
WantedBy=multi-user.target
EOF
		if [ "${EXTRA}" != "" ]
		then
			echo "${EXTRA}" >> "${TARGET}"
		fi
	done
done