openstack-ansible-os_octavia/doc/source/configure-octavia.rst
Dmitriy Rabotyagov b4e90bf68f [doc] Adjust octavia docs
Current octavia doc missing some vital parts, without which is very hard
to handle octavia deployment.

Change-Id: If6841452b8659b0f3c1240dda56898babf1e0c89
2020-12-15 09:19:37 +00:00

11 KiB

Configuring the Octavia Load Balancing service (optional)

Octavia is an OpenStack project which provides operator-grade Load Balancing (as opposed to the namespace driver) by deploying each individual load balancer to its own virtual machine and leveraging haproxy to perform the load balancing.

Octavia is scalable and has built-in high availability through active-passive.

OpenStack-Ansible deployment

  1. Create br-lbaas bridge on the controllers. Creating br-lbaas is done during the deployers host preparation and is out of scope of openstack-ansible. Some explanation of how br-lbaas is used is given below.

  2. Create the openstack-ansible container(s) for Octavia. To do that you need to define hosts for octavia-infra_hosts group in openstack_user_config.yml. Once you do this, run the following playbook:

    openstack-ansible playbooks/containers-lxc-create.yml --limit lxc_hosts,octavia_all
  3. Define required overrides of the variables in defaults/main.yml of the openstack-ansible octavia role.

  4. Run the os-octavia playbook

    openstack-ansible playbooks/os-octavia-install.yml
  5. Run the haproxy-install.yml playbook to add the new octavia API endpoints to the load balancer.

Setup a neutron network for use by octavia

Octavia needs connectivity between the control plane and the load balancing VMs. For this purpose a provider network should be created which gives L2 connectivity between the octavia services on the controllers (either containerised or deployed on metal) and the octavia amphora VMs. Refer to the appropriate documentation for the octavia service and consult the tests in this project for a working example.

Special attention needs to be applied to the provider network --allocation-pool not to have ip addresses which overlap with those assigned to hosts, lxc containers or other infrastructure such as routers or firewalls which may be in use.

An example which gives 172.29.232.0-9/22 to the OSA dynamic inventory and the remainder of the addresses to the neutron allocation pool without overlap is as follows:

In openstack_user_config.yml the following:

#the address range for the whole lbaas network
cidr_networks:
   lbaas: 172.29.232.0/22

#the range of ip addresses excluded from the dynamic inventory
used_ips:
   - "172.29.232.10,172.29.235.200"

And define in user_variables.yml:

#the range of addresses which neutron can allocate for amphora VM
octavia_management_net_subnet_allocation_pools: "172.29.232.10-172.29.235.200"

Note

The system will deploy an iptables firewall if octavia_ip_tables_fw is set to True (the default). This adds additional protection to the control plane in the rare instance a load balancing vm is compromised. Please review carefully the rules and adjust them for your installation. Please be aware that logging of dropped packages is not enabled and you will need to add those rules manually.

FLAT networking scenario

In a general case, neutron networking can be a simple flat network. However in a complex case, this can be whatever you need and want. Ensure you adjust the deployment accordingly. An example entry into openstack_user_config.yml is shown below:

- network:
   container_bridge: "br-lbaas"
   container_type: "veth"
   container_interface: "eth14"
   host_bind_override: "bond0"  # Defines neutron physical network mapping
   ip_from_q: "octavia"
   type: "flat"
   net_name: "octavia"
   group_binds:
     - neutron_linuxbridge_agent
     - octavia-worker
     - octavia-housekeeping
     - octavia-health-manager

There are a couple of variables which need to be adjusted if you don't use lbaas for the provider network name and lbaas-mgmt for the neutron name. Furthermore, the system tries to infer certain values based on the inventory which might not always work and hence might need to be explicitly declared. Review the file defaults/main.yml for more information.

The octavia ansible role can create the required neutron networks itself. Please review the corresponding settings - especially octavia_management_net_subnet_cidr should be adjusted to suit your environment. Alternatively, the neutron network can be pre-created elsewhere and consumed by Octavia.

VLAN networking scenario

In case you want to leverage standard vlan networking for the Octavia management network the definition in openstack_user_config.yml may look like this:

- network:
    container_bridge: "br-lbaas"
    container_type: "veth"
    container_interface: "eth14"
    ip_from_q: "lbaas"
    type: "raw"
    group_binds:
      - neutron_linuxbridge_agent
      - octavia-worker
      - octavia-housekeeping
      - octavia-health-manager

Add extend user_variables.yml with following overrides:

octavia_provider_network_name: vlan
octavia_provider_network_type: vlan
octavia_provider_segmentation_id: 400
octavia_container_network_name: lbaas_address

In addition to this, you will need to ensure that you have an interface that links neutron-managed br-vlan with br-lbaas on the controller nodes (for the case when br-vlan already exists on the controllers when they also host the neutron L3 agent). Making veth pairs or macvlans for this might be suitable.

Building Octavia images

Note

The default behavior is to download a test image from the OpenStack artifact storage the Octavia team provides daily. Because this image doesn't apply operating system security patches in a timely manner it is unsuited for production use.

Some Operating System vendors might provide official amphora builds or an organization might maintain their own artifact storage - for those cases the automatic download can be leveraged, too.

Images using the diskimage-builder must be built outside of a container. For this process, use one of the physical hosts within the environment.

  1. Install the necessary packages and configure a Python virtual environment

    apt-get install qemu uuid-runtime curl kpartx git jq python-pip
    pip install virtualenv
    
    virtualenv /opt/octavia-image-build
    source /opt/octavia-image-build/bin/activate
  2. Clone the necessary repositories and dependencies

    git clone https://opendev.org/openstack/octavia.git
    
    /opt/octavia-image-build/bin/pip install --isolated \
      git+https://git.openstack.org/openstack/diskimage-builder.git
  3. Run Octavia's diskimage script

    In the octavia/diskimage-create directory run:

    ./diskimage-create.sh

    Disable octavia-image-build venv:

    deactivate
  4. Upload the created user images into the Image (glance) Service:

    openstack image create --disk-format qcow2 \
       --container-format bare --tag octavia-amphora-image --file amphora-x64-haproxy.qcow2 \
       --private --project service amphora-x64-haproxy

    Note

    Alternatively you can specify the new image in the appropriate settings and rerun the ansible with an appropriate tag.

You can find more information abpout the diskimage script and the process at https://opendev.org/openstack/octavia/tree/master/diskimage-create

Here is a script to perform all those tasks at once:

#/bin/sh

apt-get install qemu uuid-runtime curl kpartx git jq
pip -v >/dev/null || {apt-get install python-pip}
pip install virtualenv
virtualenv /opt/octavia-image-build || exit 1
source /opt/octavia-image-build/bin/activate

pushd /tmp
git clone https://opendev.org/openstack/octavia.git
/opt/octavia-image-build/bin/pip install --isolated \
 git+https://git.openstack.org/openstack/diskimage-builder.git

pushd octavia/diskimage-create
./diskimage-create.sh
mv amphora-x64-haproxy.qcow2 /tmp
deactivate

popd
popd

# upload image
openstack image delete amphora-x64-haproxy
openstack image create --disk-format qcow2 \
  --container-format bare --tag octavia-amphora-image --file /tmp/amphora-x64-haproxy.qcow2 \
  --private --project service amphora-x64-haproxy

Note

If you have trouble installing dib-utils from pipy consider installing it directly from source pip install git+https://opendev.org/openstack/dib-utils.git

Creating the cryptographic certificates

Note

For production installation make sure that you review this very carefully with your own security requirements and potantially use your own CA to sign the certificates.

The system will automatically generate and use self-signed certificates with different Certificate Authorities for control plane and amphora. Make sure to store a copy in a safe place for potential disaster recovery.

Optional: Configuring Octavia with ssh access to the amphora

In rare cases it might be beneficial to gain ssh access to the amphora for additional trouble shooting. Follow these steps to enable access.

  1. Configure Octavia accordingly

    Add a octavia_ssh_enabled: True to the user file in /etc/openstack-deploy

  2. Run os_octavia role. SSH key will be generated and uploaded

Note

SSH key will be stored on the octavia_keypair_setup_host (which by default is localhost) in ~/.ssh/{{ octavia_ssh_key_name }}

Optional: Tuning Octavia for production use

Please have a close look at the main.yml for tunable parameters. The most important change is to set Octavia into ACTIVE_STANDBY mode by adding octavia_loadbalancer_topology: ACTIVE_STANDBY and octavia_enable_anti_affinity=True to ensure that the active and passive amphora are (depending on the anti-affinity filter deployed in nova) on two different hosts to the user file in /etc/openstack-deploy

Also we suggest setting more specific octavia_cert_dir to prevent accidental certificate rotation.