zdohnal at redhat.com
Tue Dec 20 04:48:28 PST 2016
Hi, I encountered this issue on Fedora 25 with CUPS-2.2.0, but it worked on RHEL 7 with CUPS-1.6.3. I have stopped and disabled Network Manager, network is controlled by systemd-networkd (enabled+started), systemd-resolved (enabled+started) is in charge of DNS. My configuration is this: $ cat /etc/systemd/network/ens9.network [Match] Name=ens9 [Network] IPForward=no Address=fd3b:d910:cd43::3/64 $ $ cat /etc/systemd/system/systemd-networkd.service.d/local.conf [Service] ExecStartPre=-/sbin/ip link set eth0 down ExecStartPre=-/sbin/ip addr flush dev eth0 Restart=on-failure $ $ cat /etc/cups/cupsd.conf MaxLogSize 0 LogLevel warn Listen localhost:631 Listen /var/run/cups/cups.sock Listen [fd3b:d910:cd43::3]:631 Browsing Off DefaultShared no WebInterface Yes DefaultEncryption Never HostNameLookups on <Location /> Order allow,deny Allow from all </Location> <Policy default> <Limit All> Allow from All </Limit> </Policy> $ $ cat /etc/systemd/system/cups.service.d/local.conf [Service] ExecStartPre=/bin/sleep 2 LimitCORE=1073741824 $ $ cat /etc/systemd/network/wired.network [Match] Name=eth0 [Network] IPForward=no DHCP=ipv4 [DHCP] UseHostname=true SendHostname=true $ And I created symlink /etc/resolv.conf, which is pointed to /run/systemd/resolve/resolv.conf: $ ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf File /etc/resolv.conf contains: nameserver 192.168.122.1 Then when I opened CUPS web interface and ran strace on cupsd process, I saw correct IP of nameserver in strace output: connect(6, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.122.1")}, 16) = 0 recvfrom(6, "\0019\205\200\0\1\0\1\0\0\0\0\16dnsmasq_server\0\0\1\0\1\300\f\0\1\0\1\0\0\0\0\0\4\300\250z\27", 1024, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.122.1")}, [16]) = 48 , but when I changed nameserver in /etc/resolv.conf to, for example, 8.8.8.8, CUPS still worked with old nameserver until CUPS is restarted. This behavior works with CUPS-1.6.3, so was there any changes regarding using /etc/resolv.conf by CUPS? Or it is regression? Thank you in advance. Best regards, Zdenek