external.yml

# Playbook to setup external networking and overcloud endpoint access on the undercloud

- hosts: undercloud
  gather_facts: yes
  vars:
       external_interface: "{{ hostvars['localhost']['external_interface'] }}"
  tasks:
      - name: set ext_interface for baremetal
        block:
          - name: get ext_interface
            shell: |
              for i in /sys/class/net/*
              do
                udevcontent=`udevadm info -p $i --query property`
                if [[ $udevcontent =~ {{ external_interface }} ]]
                then
                  ext_interface=`echo $i | cut -d '/' -f 5`
                  break
                fi
              done
              echo $ext_interface
            register: ext_interface

          - name: set ext_iface
            set_fact:
              ext_iface: "{{ ext_interface.stdout }}"
        when: virtual_uc != true and composable_roles == false

      - name: set ext_iface
        set_fact:
          ext_iface: "{{ hostvars['localhost']['external_interfaces'][0] }}"
        when: composable_roles and lab_name in ['scale', 'alias']

      - name: fail when both public_external_interface and external_network_vlan_id defined
        fail:
          msg: Both public_external_interface and external_network_vlan_id defined
        when: public_external_interface is defined and external_network_vlan_id is defined

      - name: set ext_iface
        set_fact:
          ext_iface: "{{ vm_external_interface }}"
        when: virtual_uc == true

      # "Reverse path" filter prevents packets from coming in or going out on
      #  an unexpected interface to help prevent routing loops (check with lab team).
      # The default route on undercloud was out the primary foreman interface,
      # so when undercloud gets packets coming in on the 4th NIC, it sends the traffic back
      # out the foreman interface. Turning off this configuration enables to use
      # public_external_interface i.e 4th interface
      - name: disable rp_filter
        shell: |
            for f in $(find /proc/sys/net/ipv4 -name rp_filter) ; do echo 0 > $f ; done
        become: true
        ignore_errors: true
        when: public_external_interface is defined

      - name: create vlan interface on external interface
        vars:
            vlan_interface: "{{ ext_iface }}.{{ external_network_vlan_id }}"
        shell: |
            ip link add link {{ ext_iface }} name {{ vlan_interface }} type vlan id {{ external_network_vlan_id }}
            ip link set dev {{ ext_iface }} up
            ip link set dev {{ vlan_interface }} up
            ip a a {{ external_gateway }} dev {{ vlan_interface }}
        become: true
        ignore_errors: true
        when: external_network_vlan_id is defined

      - name: add ip on when external interface is real public interface
        shell: |
            ip a a {{ external_gateway }} dev {{ ext_iface }}
        become: true
        ignore_errors: true
        when: external_network_vlan_id is not defined

      - name: get default route
        shell: |
            ip r | grep default | cut -d ' ' -f5
        register: default_route
        become: true
        when: external_network_vlan_id is defined

      - name: masquerade on public interface
        shell: |
            iptables -t nat -A POSTROUTING -o {{ default_route.stdout }} -j MASQUERADE
        become: true
        when: external_network_vlan_id is defined