Chapter 8. Performing Tasks after Overcloud Creation

The overcloud requires a Tenant network for instances. Source the overcloud and create an initial Tenant network in Neutron. For example:

$ source ~/overcloudrc
$ openstack network create default
$ openstack subnet create default --network default --gateway 172.20.1.1 --subnet-range 172.20.0.0/16

This creates a basic Neutron network called default. The overcloud automatically assigns IP addresses from this network using an internal DHCP mechanism.

Confirm the created network:

$ openstack network list
+-----------------------+-------------+--------------------------------------+
| id                    | name        | subnets                              |
+-----------------------+-------------+--------------------------------------+
| 95fadaa1-5dda-4777... | default     | 7e060813-35c5-462c-a56a-1c6f8f4f332f |
+-----------------------+-------------+--------------------------------------+

You need to create the External network on the overcloud so that you can assign floating IP addresses to instances.

Source the overcloud and create an External network in Neutron. For example:

$ source ~/overcloudrc
$ openstack network create public --external --provider-network-type flat --provider-physical-network datacentre
$ openstack subnet create public --network public --dhcp --allocation-pool start=10.1.1.51,end=10.1.1.250 --gateway 10.1.1.1 --subnet-range 10.1.1.0/24

In this example, you create a network with the name public. The overcloud requires this specific name for the default floating IP pool. This is also important for the validation tests in Section 8.5, “Validating the Overcloud”.

This command also maps the network to the datacentre physical network. As a default, datacentre maps to the br-ex bridge. Leave this option as the default unless you have used custom neutron settings during the overcloud creation.

$ source ~/overcloudrc
$ openstack network create public --external --provider-network-type vlan --provider-physical-network datacentre --provider-segment 104
$ openstack subnet create public --network public --dhcp --allocation-pool start=10.1.1.51,end=10.1.1.250 --gateway 10.1.1.1 --subnet-range 10.1.1.0/24

The provider:segmentation_id value defines the VLAN to use. In this case, you can use 104.

Confirm the created network:

$ openstack network list
+-----------------------+-------------+--------------------------------------+
| id                    | name        | subnets                              |
+-----------------------+-------------+--------------------------------------+
| d474fe1f-222d-4e32... | public      | 01c5f621-1e0f-4b9d-9c30-7dc59592a52f |
+-----------------------+-------------+--------------------------------------+

Floating IP networks can use any bridge, not just br-ex, as long as you meet the following conditions:

Create the Floating IP network after creating the overcloud:

$ source ~/overcloudrc
$ openstack network create ext-net --external --provider-physical-network floating --provider-network-type vlan --provider-segment 105
$ openstack subnet create ext-subnet --network ext-net --dhcp --allocation-pool start=10.1.2.51,end=10.1.2.250 --gateway 10.1.2.1 --subnet-range 10.1.2.0/24

A provider network is a network attached physically to a network existing outside of the deployed overcloud. This can be an existing infrastructure network or a network that provides external access directly to instances through routing instead of floating IPs.

When creating a provider network, you associate it with a physical network, which uses a bridge mapping. This is similar to floating IP network creation. You add the provider network to both the Controller and the Compute nodes because the Compute nodes attach VM virtual network interfaces directly to the attached network interface.

For example, if the desired provider network is a VLAN on the br-ex bridge, use the following command to add a provider network on VLAN 201:

$ source ~/overcloudrc
$ openstack network create provider_network --provider-physical-network datacentre --provider-network-type vlan --provider-segment 201 --share

This command creates a shared network. It is also possible to specify a tenant instead of specifying --share. That network will only be available to the specified tenant. If you mark a provider network as external, only the operator may create ports on that network.

Add a subnet to a provider network if you want neutron to provide DHCP services to the tenant instances:

$ source ~/overcloudrc
$ openstack subnet create provider-subnet --network  provider_network --dhcp --allocation-pool start=10.9.101.50,end=10.9.101.100 --gateway 10.9.101.254 --subnet-range 10.9.101.0/24

Other networks might require access externally through the provider network. In this situation, create a new router so that other networks can route traffic through the provider network:

$ openstack router create external
$ openstack router set --external-gateway provider_network external

Attach other networks to this router. For example, if you had a subnet called subnet1, you can attach it to the router with the following commands:

$ openstack router add subnet external subnet1

This adds subnet1 to the routing table and allows traffic using subnet1 to route to the provider network.

The overcloud uses the OpenStack Integration Test Suite (tempest) tool set to conduct a series of integration tests. This section provides information on preparations for running the integration tests. For full instruction on using the OpenStack Integration Test Suite, see the OpenStack Integration Test Suite Guide.

$ source ~/stackrc
$ sudo ovs-vsctl add-port br-ctlplane vlan201 tag=201 -- set interface vlan201 type=internal
$ sudo ip l set dev vlan201 up; sudo ip addr add 172.16.0.201/24 dev vlan201

Before running the OpenStack Integration Test Suite, check that the heat_stack_owner role exists in your overcloud:

$ source ~/overcloudrc
$ openstack role list
+----------------------------------+------------------+
| ID                               | Name             |
+----------------------------------+------------------+
| 6226a517204846d1a26d15aae1af208f | swiftoperator    |
| 7c7eb03955e545dd86bbfeb73692738b | heat_stack_owner |
+----------------------------------+------------------+

If the role does not exist, create it:

$ openstack role create heat_stack_owner

$ source ~/stackrc
$ sudo ovs-vsctl del-port vlan201

Sometimes you might intend to modify the overcloud to add additional features, or change the way it operates. To modify the overcloud, make modifications to your custom environment files and Heat templates, then rerun the openstack overcloud deploy command from your initial overcloud creation. For example, if you created an overcloud using Section 5.6, “Creating the Overcloud with the CLI Tools”, you would rerun the following command:

$ source ~/stackrc
$ openstack overcloud deploy --templates \
  -e ~/templates/node-info.yaml \
  -e /usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml \
  -e ~/templates/network-environment.yaml \
  -e ~/templates/storage-environment.yaml \
  --ntp-server pool.ntp.org

The director checks the overcloud stack in heat, and then updates each item in the stack with the environment files and heat templates. It does not recreate the overcloud, but rather changes the existing overcloud.

If you aim to include a new environment file, add it to the openstack overcloud deploy command with a -e option. For example:

$ source ~/stackrc
$ openstack overcloud deploy --templates \
  -e ~/templates/new-environment.yaml \
  -e /usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml \
  -e ~/templates/network-environment.yaml \
  -e ~/templates/storage-environment.yaml \
  -e ~/templates/node-info.yaml \
  --ntp-server pool.ntp.org

This includes the new parameters and resources from the environment file into the stack.

Use the following procedure if you have an existing OpenStack environment and aim to migrate its virtual machines to your Red Hat OpenStack Platform environment.

Create a new image by taking a snapshot of a running server and download the image.

$ openstack server image create instance_name --name image_name
$ openstack image save image_name --file exported_vm.qcow2

Upload the exported image into the overcloud and launch a new instance.

$ openstack image create imported_image --file exported_vm.qcow2 --disk-format qcow2 --container-format bare
$ openstack server create  imported_instance --key-name default --flavor m1.demo --image imported_image --nic net-id=net_id

In some situations, you might perform maintenance on an overcloud Compute node. To prevent downtime, migrate the VMs on the Compute node to another Compute node in the overcloud.

The director configures all Compute nodes to provide secure migration. All Compute nodes also require a shared SSH key to provide each host’s nova user with access to other Compute nodes during the migration process. The director creates this key using the OS::TripleO::Services::NovaCompute composable service. This composable service is one of the main services included on all Compute roles by default (see "Composable Services and Custom Roles" in Advanced Overcloud Customization).

To migrate an instance:

This migrates all instances from a Compute node. You can now perform maintenance on the node without any instance downtime. To return the Compute node to an enabled state, run the following command:

$ source ~/overcloudrc
$ openstack compute service set [hostname] nova-compute --enable

The director provides the ability to run Ansible-based automation on your OpenStack Platform environment. The director uses the tripleo-ansible-inventory command to generate a dynamic inventory of nodes in your environment.

To view a dynamic inventory of nodes, run the tripleo-ansible-inventory command after sourcing stackrc:

$ souce ~/stackrc
$ tripleo-ansible-inventory --list

The --list option provides details on all hosts.

This outputs the dynamic inventory in a JSON format:

{"overcloud": {"children": ["controller", "compute"], "vars": {"ansible_ssh_user": "heat-admin"}}, "controller": ["192.168.24.2"], "undercloud": {"hosts": ["localhost"], "vars": {"overcloud_horizon_url": "http://192.168.24.4:80/dashboard", "overcloud_admin_password": "abcdefghijklm12345678", "ansible_connection": "local"}}, "compute": ["192.168.24.3"]}

To execute Ansible playbooks on your environment, run the ansible command and include the full path of the dynamic inventory tool using the -i option. For example:

ansible [HOSTS] -i /bin/tripleo-ansible-inventory [OTHER OPTIONS]

To avoid accidental removal of the overcloud with the heat stack-delete overcloud command, Heat contains a set of policies to restrict certain actions. Edit the /etc/heat/policy.json and find the following parameter:

"stacks:delete": "rule:deny_stack_user"

Change it to:

"stacks:delete": "rule:deny_everybody"

Save the file.

This prevents removal of the overcloud with the heat client. To allow removal of the overcloud, revert the policy to the original value.

The whole overcloud can be removed when desired.

Delete any existing overcloud:

$ source ~/stackrc
$ openstack overcloud delete overcloud

Confirm the deletion of the overcloud:

$ openstack stack list

Deletion takes a few minutes.

Once the removal completes, follow the standard steps in the deployment scenarios to recreate your overcloud.

The Identity Service (keystone) uses a token-based system for access control against the other OpenStack services. After a certain period, the database will accumulate a large number of unused tokens; a default cron job flushes the token table every day. It is recommended that you monitor your environment and adjust the token flush interval as needed.

For the overcloud, you can adjust the interval using the KeystoneCronToken values. For more information, see the Overcloud Parameters guide.