Instance Cannot Contact Metadata Service (Ubuntu 16.04)

Problem

  • An instance is unable to contact the metadata service via the metadata proxy IP (169.254.169.254) with an error similar to the following.
Copy
  • The gateway IP for the metadata proxy route is associated with a reserved DHCP port.

1. Identify the gateway IP.

# route -nKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Iface...169.254.169.254 10.0.0.1 255.255.255.255 UGH 0 0 0 ens3

2. Track the IP down to a Neutron port.

# openstack port list --network __NETWORK_ID__ --long --fit-width | grep -w 10.0.0.1

3. Check the device ID of the port.

# openstack port show __PORT_ID__ -f value -c device_id

- The value should be reserved_dhcp_port. If not, you are likely facing a separate issue with that particular DHCP agent.

Environment

  • Platform9 Managed OpenStack - All Versions
  • Ubuntu 16.04

Cause

A DHCP agent failover has occurred and thus the IP/route to the Neutron metadata proxy has changed.

Resolution

  1. Remove the route for the metadata proxy IP.
Copy
  1. Run dhclient.
Copy
  1. Check that the gateway IP for the 169.254.169.254 route has been updated.
Copy
  1. Ensure that the metadata service is reachable via the proxy IP.
Copy
Type to search, ESC to discard
Type to search, ESC to discard
Type to search, ESC to discard