Openstack 17 network gateway not defined as expected

Solution Verified - Updated -

Environment

  • Red Hat Openstack Plataform 17

Issue

When adding a compute node with specific network/VLAN/DCN to environment, no default gateway is set or is set to ctlplane network gateway.

Resolution

  1. Edit template to enable network config update.

    - name: ComputeRole
defaults:
  network_config:
    network_config_update: true                                   <<== set true here

  2. Correct the route of compute role on nic-config template to use the desired network as default.

    ...
network_config:
...
- type: vlan
  use_dhcp: false
  dns_servers: {{ ctlplane_dns_nameservers }}
  domain: {{ dns_search_domains }}
  mtu: {{ subnet5_mtu }}
  vlan_id: {{ subnet5_vlan_id }}
  addresses:
  - ip_netmask: {{ subnet5_ip }}/{{ subnet5_cidr }}
  routes: {{ [subnet5_host_routes] | flatten | unique }}

  3. Run new provision.

  4. If needed, reboot the new node.

  5. Disable network config update only in the template to not cause network outage on a future deploy.

Root Cause

  • The network templates of RHOSP17 are different from RHOSP16, which can cause some confusion. Also, when upgrading this conversion needs to be reviewed.
  • If no route is set, the default is to set with ctlplane_host_routes.

Diagnostic Steps

  1. Check on the new compute node the routes created.

    [root@compute0 ~]# ip route

  2. Check on compute if the os-net-config template generated, if it contains the correct gateway configuration a reboot can be enough. If not, check templates.

    [root@compute0 ~]# cat /etc/os-net-config/config.yaml

  3. Check nic-config template for this compute role, the parameter routes normally not contains IP numbers or multiple variables as *_host_routes or a variable as *_host_routes plus 'default': True or is empty.

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