nginx on Plesk for Linux server does not start automatically after reboot: 99: Cannot assign requested address

Symptoms

• After server reboot, nginx does not get started:

  # systemctl --failed
  UNIT LOAD ACTIVE SUB DESCRIPTION
  ● nginx.service loaded failed failed Startup script for nginx service

• Domains are not working.

• OS with systemd is installed (Debian 8, CentOS 7 and etc.).

• In /var/log/nginx/error.log the following messages can be found:

  [emerg] 1140#0: bind() to [203.0.113.2]:80 failed (99: Cannot assign requested address)

• In journalctl the following entries can be found:

  # journalctl -u network.service -u network.target -u nginx.service -b
  nginx[352]: nginx: [emerg] bind() to 203.0.113.2:80 failed (99: Cannot assign requested address)
  systemd[1]: Failed to start Startup script for nginx service.
  systemd[1]: Unit nginx.service entered failed state.
  network[268]: Bringing up interface eth0:
  dhclient[665]: DHCPREQUEST on eth0 to 255.255.255.255 port 67 (xid=0x4b684081)
  dhclient[665]: DHCPACK from 203.0.113.2 (xid=0x4b684081)
  network[268]: [ OK ]

• However, nginx can be started manually without any issues:

  # systemctl start nginx.service

Cause

Delay in assigning of IP address to a network interface. For example, because of delayed response from DHCP server.

Resolution

1. Connect to the server using SSH.

2. Make sure that network interfaces are enabled on system boot:

   • for RHEL, CentOS, CloudLinux:

     # grep -r "ONBOOT" /etc/sysconfig/network-scripts/ifcfg-*
     /etc/sysconfig/network-scripts/ifcfg-lo:ONBOOT=yes
     /etc/sysconfig/network-scripts/ifcfg-venet0:ONBOOT=yes
     /etc/sysconfig/network-scripts/ifcfg-venet0:0:ONBOOT=yes

   • for Debian and Ubuntu:

     # grep auto /etc/network/interfaces
     # This configuration file is auto-generated.
     auto lo
     auto venet0
     auto venet0:0

3. Back up the nginx startup script /etc/systemd/system/multi-user.target.wants/nginx.service:

   # cp /etc/systemd/system/multi-user.target.wants/nginx.service{,.bk}

4. Make sure that the package systemd-networkd is installed on the server. Install it if it is not installed:

   • for RHEL, CentOS, CloudLinux:

     # yum install systemd-networkd

   • for Debian and Ubuntu:
     Should be installed by default.

     The service will ensure that network interfaces are up and have IP addresses bound. For additional details, refer to http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/

5. If Plesk 17.5 or older is used, proceed as follows to create the file /etc/systemd/system/nginx.service.d/override.conf with an nginx startup parameter to be executed only after the network is up and all IP addresses are assigned:

   • Run the following command. It will open the default text editor on the server:

     # systemctl edit nginx.service

     Add the following line, save and exit the file:

     After=network-online.target remote-fs.target nss-lookup.target

6. Reboot the server:

   # reboot

If it does not help, additional action is required:

• For SystemD add the following line in [Service] section in /etc/systemd/system/multi-user.target.wants/nginx.service file:

  ExecStartPre=/bin/sleep 10

  Note: Increase timeout if needed.

• For OS without SystemD, edit /etc/init.d/nginx adding sleep command to the start, so it should look like:

  # grep -i "start()" /etc/init.d/nginx
  start() { sleep 20

• Reboot the server: 

  # reboot