clusterctl config file is located at
$HOME/.cluster-api/clusterctl.yaml and it can be used to:
- Customize the list of providers and provider repositories.
- Provide configuration values to be used for variable substitution when installing providers or creating clusters.
- Define image overrides for air-gapped environments.
clusterctl CLI is designed to work with providers implementing the clusterctl Provider Contract.
Each provider is expected to define a provider repository, a well-known place where release assets are published.
clusterctl ships with providers sponsored by SIG Cluster
clusterctl config repositories to get a list of supported
providers and their repository configuration.
Users can customize the list of available providers using the
clusterctl configuration file, as shown in the following example:
providers: # add a custom provider - name: "my-infra-provider" url: "https://github.com/myorg/myrepo/releases/latest/infrastructure_components.yaml" type: "InfrastructureProvider" # override a pre-defined provider - name: "cluster-api" url: "https://github.com/myorg/myforkofclusterapi/releases/latest/core_components.yaml" type: "CoreProvider"
See provider contract for instructions about how to set up a provider repository.
When installing a provider
clusterctl reads a YAML file that is published in the provider repository; while executing
clusterctl can substitute certain variables with the ones provided by the user.
The same mechanism also applies when
clusterctl reads the cluster templates YAML published in the repository, e.g.
when injecting the Kubernetes version to use, or the number of worker machines to create.
The user can provide values using OS environment variables, but it is also possible to add
variables in the
clusterctl config file:
# Values for environment variable substitution AWS_B64ENCODED_CREDENTIALS: XXXXXXXX
In case a variable is defined both in the config file and as an OS environment variable, the latter takes precedence.
clusterctl uses an overrides layer to read in injected provider components,
cluster templates and metadata. By default, it reads the files from
The directory structure under the
overrides directory should follow the
├── bootstrap-kubeadm │ └── v0.3.0 │ └── bootstrap-components.yaml ├── cluster-api │ └── v0.3.0 │ └── core-components.yaml ├── control-plane-kubeadm │ └── v0.3.0 │ └── control-plane-components.yaml └── infrastructure-aws └── v0.5.0 ├── cluster-template-dev.yaml └── infrastructure-components.yaml
For developers who want to generate the overrides layer, see Run the local-overrides hack!.
Once these overrides are specified,
clusterctl will use them instead of
getting the values from the default or specified providers.
One example usage of the overrides layer is that it allows you to deploy clusters with custom templates that may not be available from the official provider repositories. For example, you can now do
clusterctl config cluster mycluster --flavor dev --infrastructure aws:v0.5.0 -v5
-v5 provides verbose logging which will confirm the usage of the
Using Override="cluster-template-dev.yaml" Provider="infrastructure-aws" Version="v0.5.0"
Another example, if you would like to deploy a custom version of CAPA, you can
make changes to
infrastructure-components.yaml in the overrides folder and
clusterctl init --infrastructure aws:v0.5.0 -v5 ... Using Override="infrastructure-components.yaml" Provider="infrastructure-aws" Version="v0.5.0" ...
If you prefer to have the overrides directory at a different location (e.g.
/Users/foobar/workspace/dev-releases) you can specify the overrides
directory in the clusterctl config file as
When working in air-gapped environments, it’s necessary to alter the manifests to be installed in order to pull
images from a local/custom image repository instead of public ones (e.g.
clusterctl configuration file can be used to instruct
clusterctl to override images automatically.
This can be achieved by adding an
images configuration entry as shown in the example:
images: all: repository: myorg.io/local-repo
Please note that the image override feature allows for more fine-grained configuration, allowing to set image overrides for specific components, for example:
images: all: repository: myorg.io/local-repo cert-manager: tag: v0.11.1
In this example we are overriding the image repository for all the components and the image tag for all the images in the cert-manager component.
For situations when resources are limited or the network is slow, the cert-manager wait time to be running can be customized by adding a field to the clusterctl config file, for example:
The value string is a possibly signed sequence of decimal numbers, each with optional fraction and a unit suffix, such as “300ms”, “-1.5h” or “2h45m”. Valid time units are “ns”, “us” (or “µs”), “ms”, “s”, “m”, “h”.
If no value is specified or the format is invalid, the default value of 10 minutes will be used.