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Development Guide

This document explains how to develop Cluster API Provider OpenStack.

Using your own capi-openstack controller image for testing cluster creation or deletion

You need to create your own openstack-capi controller image for testing cluster creation or deletion by your code. The image is stored in the docker registry. You need to create an account of Docker registry in advance.

Building and upload your own capi-openstack controller image

Log in to your registry account. Export the following environment variables which will be used by the Makefile.

REGISTRYThe registry<username>
IMAGE_NAMEThe image name (default: capi-openstack-controller)Nocapi-openstack-controller
TAGThe image version (default: dev)Nolatest

Execute the command to build and upload the image to the Docker registry.

make docker-build docker-push

Using your own capi-openstack controller image

After generating infrastructure-components.yaml, replace the with your image.

Testing Cluster Creation using the ‘dev-test’ ClusterClass with Tilt

This guide demonstrates how to create a Kubernetes cluster using a ClusterClass, specifically designed for a development environment. It includes configuring secrets, applying the ClusterClass, and creating a cluster with Tilt.

The dev-test ClusterClass is designed for development. This means that it is using the latest (potentially unstable) API version. The defaults are also aligned with the devstack setup (documented below) to make it as easy as possible to use in a development flow. However, this also means that it may not be well suited for general usage.

Developing with Tilt

We have support for using Tilt for rapid iterative development. Please visit the Cluster API documentation on Tilt for information on how to set up your development environment.

The Tiltfile in the Cluster API repository can be used as is with CAPO, but we need to add some configuration. For using Tilt with ClusterClass, update your tilt-settings.yaml file (located in the root of the CAPI repository) as described:

  # Make Tilt aware of the CAPO templates
  - ../cluster-api-provider-openstack/templates

  # [Optional] SSH Keypair Name for Instances in OpenStack (Default: "")
  OPENSTACK_SSH_KEY_NAME: "<openstack_keypair_name>"
  # [Optional] Control Plane Machine Flavor (Default: m1.medium)
  OPENSTACK_CONTROL_PLANE_MACHINE_FLAVOR: "<openstack_control_plane_machine_flavor>"
  # [Optional] Node Machine Flavor (Default: m1.small)
  OPENSTACK_NODE_MACHINE_FLAVOR: "<openstack_node_machine_flavor>"
  # [Optional] OpenStack Cloud Environment (Default: capo-e2e)
  OPENSTACK_CLOUD: "<openstack_cloud>"

# [Optional] Automatically apply a kustomization, e.g. for adding the clouds.yaml secret
  secret_kustomization: /path/to/kustomize/secret/configuration

Apply ClusterClass and create Cluster

When you are happy with the configuration, start the environment as explained in the CAPI documentation. Open the Tilt dashboard in your browser. After a while, you should be able to find resources called CAPO.clusterclasses and CAPO.templates. These shoud correspond to what exists in the templates folder and you should see widgets for applying and deleting them.

Note: When you apply a cluster template, there will be a KUBERNETES_VERSION variable. This variable is used to pick the image used! Ensure that an image named ubuntu-2204-kube-{{ KUBERNETES_VERSION }} is available in your environment, corresponding to that Kubernetes version.

Note: All clusters created from the dev-test ClusterClass will require a secret named dev-test-cloud-config with the clouds.yaml to be used by CAPO for interacting with OpenStack. You can create it manually or see below how to make Tilt automate it.

Automatically applying kustomizations with Tilt

This explains how to automatically create the secret containing clouds.yaml. The same procedure can be used for any other things you want to create in the cluster.

Ensure the specified path (/path/to/kustomize/secret/configuration) contains both the clouds.yaml file and a kustomization.yaml file. The kustomization.yaml should define the necessary resources, such as a Kubernetes secret, using the clouds.yaml file.

For example, if you want to automatically create a secret named dev-test-cloud-config with the content of your clouds.yaml every time you do tilt up, you could do the following.

Create a folder to hold the kustomization. We will use /tmp/capo-dev as example here.

Add the clouds.yaml file that you want to use to the folder. It could look something like this:

      username: demo
      password: secretadmin
      # If using application credentials you would have something like this instead:
      # auth_type: v3applicationcredential
      # application_credential_id: abc123
      # application_credential_secret: 456def
      user_domain_id: default
      domain_id: default
      project_name: demo
    verify: false
    region_name: RegionOne

Create a kustomization file named kustomization.yaml in the same folder:

kind: Kustomization
# Do not add random hash to the end of the secret name
  disableNameSuffixHash: true
- files:
  - clouds.yaml
  name: dev-test-cloud-config
  type: Opaque

If you now add /tmp/capo-dev to the additional_kustomizations, tilt will automatically apply the secret.

To check that the kustomization produces the desired output, do kustomize build /tmp/capo-dev.

Using the ‘dev-test’ ClusterClass without Tilt

If you want to use the ClusterClass without Tilt, you will need to follow these steps instead of the above.

Creating a Kind Cluster

Create a Kind cluster and deploy CAPO.

Note: As the dev-test ClusterClass is made for development, it may be using a newer API version than what is in the latest release. You will need to use local artifacts for this to work in most cases!

kind create cluster
clusterctl init --infrastructure openstack

Secret Configuration

CAPO needs a clouds.yaml file in order to manage the OpenStack resources needed for the Cluster. This should be supplied as a secret named dev-test-cloud-config. You can create this secret for example with:

kubectl create secret generic dev-test-cloud-config --from-file=clouds.yaml

Apply the ClusterClass and create Clusters

You can use clusterctl to render the ClusterClass:

clusterctl generate yaml  --from templates/clusterclass-dev-test.yaml

Create a cluster using the development template, that makes use of the ClusterClass:

clusterctl generate cluster my-cluster --kubernetes-version=v1.29.0 --from templates/cluster-template-development.yaml > my-cluster.yaml
kubectl apply -f my-cluster.yaml

Running E2E tests locally

You can run the E2E tests locally with:

make test-e2e OPENSTACK_CLOUD_YAML_FILE=/path/to/clouds.yaml OPENSTACK_CLOUD=mycloud

where mycloud is an entry in clouds.yaml.

The E2E tests:

  • Build a CAPO image from the local working directory
  • Create a kind cluster locally
  • Deploy downloaded CAPI, and locally-build CAPO to kind
  • Create an e2e namespace per-test on the kind cluster
  • Deploy cluster templates to the test namespace
  • Create test clusters on the target OpenStack

Support for clouds using SSL

If your cloud requires a cacert you must also pass this to make via OPENSTACK_CLOUD_CACERT_B64, i.e.:

make test-e2e OPENSTACK_CLOUD_YAML_FILE=/path/to/clouds.yaml OPENSTACK_CLOUD=my_cloud \
              OPENSTACK_CLOUD_CACERT_B64=$(base64 -w0 /path/to/mycloud-ca.crt)

CAPO deployed in the local kind cluster will automatically pick up a cacert defined in your clouds.yaml so you will see servers created in OpenStack without specifying OPENSTACK_CLOUD_CACERT_B64. However, the cacert won’t be deployed to those servers, so kubelet will fail to start.

Support for clouds with multiple external networks

If your cloud contains only a single external network CAPO will automatically select that network for use by a deployed cluster. However, if there are multiple external networks CAPO will log an error and fail to create any machines. In this case you must pass the id of an external network to use explicitly with OPENSTACK_EXTERNAL_NETWORK_ID, i.e.:

make test-e2e OPENSTACK_CLOUD_YAML_FILE=/path/to/clouds.yaml OPENSTACK_CLOUD=my_cloud \

OPENSTACK_EXTERNAL_NETWORK_ID must be specified as a uuid. Specifying by name is not supported.

You can list available external networks with:

$ openstack network list --external
| ID                                   | Name     | Subnets                              |
| 27635f93-583d-454e-9c6d-3d305e7f8a22 | external | be64cd07-f8b7-4705-8446-26b19eab3914 |
| cf2e83dc-545d-490f-9f9c-4e90927546f2 | hostonly | ec95befe-72f4-4af6-a263-2aec081f47d3 |

E2E test environment

The test suite is executed in an existing OpenStack environment. You can create and manage this environment yourself or use the hacking CI scripts to provision an environment with DevStack similar to the one used for continuous integration.


The file test/e2e/data/e2e_conf.yaml and the test templates under test/e2e/data/infrastructure-openstack reference several OpenStack resources which must exist before running the test:

  • System requirements
    • Multiple nodes
    • controller: 16 CPUs / 64 GB RAM
    • worker: 8 CPUs / 32 GB RAM
  • Availability zones (for multi-AZ tests)
    • testaz1: used by all test cases
    • testaz2: used by multi-az test case
  • Services (Additional services to be enabled)
    • Octavia
    • Network trunking (neutron-trunk)
    • see Configration for more details.
  • Glance images
    • cirros-0.6.1-x86_64-disk
      • Download from
    • ubuntu-2004-kube-v1.23.10
      • Download from
      • Or generate using the images/capi directory from
        • Boot volume size must be less than 15GB
  • Flavors
    • m1.medium: used by control plane
    • m1.small: used by workers
    • m1.tiny: used by bastion
  • clouds.yaml
    • capo-e2e: for general user authorization
    • capo-e2e-admin: for administrator user authorization
    • i.e.:
            auth_url: http://Node-Address/identity
            project_name: demo
            project_domain_name: Default
            user_domain_name: Default
            username: demo
            password: secret
          region_name: RegionOne
            auth_url: http://Node-Address/identity
            project_name: demo
            project_domain_name: Default
            user_domain_name: Default
            username: admin
            password: secret
          region_name: RegionOne

Create E2E test environment

You can easily create a test environment similar to the one used during continuous integration on OpenStack, AWS or GCE with the hacking CI scripts.

The entry point for the creation of the DevStack environment is the script, which executes specific scripts to create infrastructure on different clouds:

You can switch between these cloud providers, by setting the RESOURCE_TYPE environment variable to aws-project, gce-project or openstack respectively.


Configure the following environment variables for OpenStack:

export RESOURCE_TYPE="openstack"
export OS_CLOUD=<your cloud>
export OPENSTACK_FLAVOR_controller=<flavor with >= 16 cores, 64GB RAM and 50GB storage>
export OPENSTACK_FLAVOR_worker=<flavor with >= 8 cores, 32GB RAM and 50GB storage>
export OPENSTACK_PUBLIC_NETWORK=<name of the external network>
export OPENSTACK_SSH_KEY_NAME=<your ssh key-pair name>
export SSH_PUBLIC_KEY_FILE=/home/user/.ssh/
export SSH_PRIVATE_KEY_FILE=/home/user/.ssh/id_ed25519

and create the environment by running:


Here’s a few notes to setup a DevStack environment and debug ressources (tested on m3.small from Equinix Metal:

Server side

As a root user, install and configure DevStack:

# useradd -s /bin/bash -d /opt/stack -m stack
# chmod +x /opt/stack
# echo "stack ALL=(ALL) NOPASSWD: ALL" | tee /etc/sudoers.d/stack
# sudo -u stack -i
$ git clone
$ cd devstack
$ cat > local.conf <<EOF

# Enable Logging
enable_service rabbit
enable_plugin neutron $GIT_BASE/openstack/neutron
# Octavia supports using QoS policies on the VIP port:
enable_service q-qos
enable_service placement-api placement-client
# Octavia services
enable_plugin octavia $GIT_BASE/openstack/octavia master
enable_plugin octavia-dashboard $GIT_BASE/openstack/octavia-dashboard
enable_plugin ovn-octavia-provider $GIT_BASE/openstack/ovn-octavia-provider
enable_plugin octavia-tempest-plugin $GIT_BASE/openstack/octavia-tempest-plugin
enable_service octavia o-api o-cw o-hm o-hk o-da
# Cinder
enable_service c-api c-vol c-sch
$ ./

If you want to enable web-download (i.e import images from URL):

# /etc/glance/glance-api.conf
show_multiple_locations = True

# ./horizon/openstack_dashboard/

# /etc/glance/glance-image-import.conf
image_import_plugins = ['image_decompression']

$ sudo systemctl restart devstack@g-api.service apache2

With this dev setup, it might be useful to enable DHCP for the public subnet: Admin > Network > Networks > public > Subnets > public-subnet > Edit Subnet > Subnet Details > :ballot_box_with_check: Enable DHCP + Add DNS

CAPO side

To work with this setup, it takes an update of the test/e2e/data/e2e_conf.yaml file. (NOTE: You can decide to update the m1.small flavor to avoid changing it)

diff --git a/test/e2e/data/e2e_conf.yaml b/test/e2e/data/e2e_conf.yaml
index 0d66e1f2..a3b2bd78 100644
--- a/test/e2e/data/e2e_conf.yaml
+++ b/test/e2e/data/e2e_conf.yaml
@@ -136,7 +136,7 @@ variables:
   CNI: "../../data/cni/calico.yaml"
   CCM: "../../data/ccm/cloud-controller-manager.yaml"
-  OPENSTACK_BASTION_IMAGE_NAME: "cirros-0.6.1-x86_64-disk"
+  OPENSTACK_BASTION_IMAGE_NAME: "cirros-0.5.2-x86_64-disk"
   OPENSTACK_CLOUD: "capo-e2e"
   OPENSTACK_CLOUD_ADMIN: "capo-e2e-admin"
@@ -144,10 +144,10 @@ variables:
   OPENSTACK_CLOUD_YAML_FILE: '../../../../clouds.yaml'
   OPENSTACK_IMAGE_NAME: "focal-server-cloudimg-amd64"

Before running a test:

  • start sshuttle ( to setup the network between the host and the devstack instance correctly.
sshuttle -r stack@<devstack-server-ip> -l
  • import the tested image in DevStack by matching the name defined in e2e_conf.yaml (OPENSTACK_FLATCAR_IMAGE_NAME or OPENSTACK_IMAGE_NAME)

To run a specific test, it’s possible to fill this variable E2E_GINKGO_FOCUS, if you want to SSH into an instance to debug it, it’s possible to proxy jump via the bastion and to use the SSH key generated by Nova, for example with Flatcar:

ssh -J cirros@ -i ./_artifacts/ssh/cluster-api-provider-openstack-sigs-k8s-io core@

Running E2E tests using rootless podman

You can use unprivileged podman to:

  • Build the CAPO image
  • Deploy the kind cluster

To do this you need to configure the host appropriately and pass PODMAN=1 to make, i.e.:

make test-e2e OPENSTACK_CLOUD_YAML_FILE=/path/to/clouds.yaml OPENSTACK_CLOUD=my_cloud \

Host configuration

Firstly, you must be using kernel >=5.11. If you are using Fedora, this means Fedora >= 34.

You must configure systemd and iptables as described in There is no need to configure cgroups v2 on Fedora, as it uses this by default.

You must install the podman-docker package to emulate the docker cli tool. However, this is not sufficient on its own as described below.

Running podman system service to emulate docker daemon

While kind itself supports podman, the cluster-api test framework does not. This framework is used by the CAPO tests to push test images into the kind cluster. Unfortunately the cluster-api test framework explicitly connects to a running docker daemon, so cli emulation is not sufficient for compatibility. This issue is tracked in, and the following workaround can be ignored when this is resolved.

podman includes a ‘system service’ which emulates docker. For the tests to work, this service must be running and listening on a unix socket at /var/run/docker.sock. You can achieve this with:

$ podman system service -t 0 &
$ sudo rm /var/run/docker.sock
$ sudo ln -s /run/user/$(id -u)/podman/podman.sock /var/run/docker.sock

API concepts

This sections goal is to gather various insights into the API design that can serve as a reference to explain various choices made without need to analyze discussions in individual PRs.


Starting from v1alpha8 both OpenStackMachineStatus and BastionsStatus feature a field named referencedResources which aims to include fields that list individual IDs of the resources associated with the machine or bastion. These IDs are calculated on machine or bastion creation and are not intended to be changed during the object lifecycle.

Having all the IDs of related resources saved in the statuses allows CAPO to make easy decisions about deleting the related resources when deleting the VM corresponding to the machine or bastion.