[Unit]
Description=Squid web caching proxy
After=syslog.target network.target network-online.target nss-lookup.target

[Service]
Environment="SQUID_CONF=/etc/squid/squid.conf"
Environment="SQUID_OPTS=-Y"
LimitNOFILE=16384
ExecStartPre=/usr/sbin/squid -N -z -f ${SQUID_CONF}
ExecStart=/usr/sbin/squid -N $SQUID_OPTS -f ${SQUID_CONF}
ExecReload=/usr/sbin/squid -k reconfigure -f ${SQUID_CONF}
# Note: Do NOT use ExecStop=/usr/sbin/squid -k shutdown -f ${SQUID_CONF}
# because it doesn't wait for squid to exit, causing systemd to SIGKILL squid
# right away which is certainly NOT what we want.
# Instead, enjoy the SIGTERM default which is identical to "squid -k shutdown"
# but without the nasty side effect of a (too early) SIGKILL.
#
# However per default, squid takes 30 seconds to exit which is acceptable but
# quite a long time. Fortunately, this can easily be changed to 1 second in
# /etc/squid/squid.conf: shutdown_lifetime 1 second

[Install]
WantedBy=multi-user.target