clusterctl upgrade command can be used to upgrade the version of the Cluster API providers (CRDs, controllers)
installed into a management cluster.
The upgrade procedure is designed to ensure all the providers in a management group use the same API Version of Cluster API (contract), e.g. the v1alpha 3 Cluster API contract.
A management group is a group of providers composed by a CoreProvider and a set of Bootstrap/ControlPlane/Infrastructure providers watching objects in the same namespace.
Usually, in a management cluster there is only a management group, but in case of n-core multi tenancy there can be more than one.
clusterctl upgrade plan command can be used to identify possible targets for upgrades.
clusterctl upgrade plan
Produces an output similar to this:
Checking new release availability... Management group: capi-system/cluster-api, latest release available for the v1alpha3 API Version of Cluster API (contract): NAME NAMESPACE TYPE CURRENT VERSION TARGET VERSION cluster-api capi-system CoreProvider v0.3.0 v0.3.1 kubeadm capi-kubeadm-bootstrap-system BootstrapProvider v0.3.0 v0.3.1 kubeadm capi-kubeadm-control-plane-system ControlPlaneProvider v0.3.0 v0.3.1 docker capd-system InfrastructureProvider v0.3.0 v0.3.1 You can now apply the upgrade by executing the following command: clusterctl upgrade apply --management-group capi-system/cluster-api --contract v1alpha3
The output contains the latest release available for each management group in the cluster/for each API Version of Cluster API (contract) available at the moment.
After choosing the desired option for the upgrade, you can run the following command to upgrade all the providers in the management group. This upgrades all the providers to the latest stable releases.
clusterctl upgrade apply \ --management-group capi-system/cluster-api \ --contract v1alpha3
The upgrade process is composed by three steps:
- Check the cert-manager version, and if necessary, upgrade it.
- Delete the current version of the provider components, while preserving the namespace where the provider components are hosted and the provider’s CRDs.
- Install the new version of the provider components.
Please note that clusterctl does not upgrade Cluster API objects (Clusters, MachineDeployments, Machine etc.); upgrading such objects are the responsibility of the provider’s controllers.
Multi-tenancy for Cluster API means a management cluster where multiple instances of the same
provider are installed, and this is achieved by multiple calls to
clusterctl init, and in most cases, each one with
different environment variables for customizing the provider instances.
In order to upgrade a multi-tenancy management cluster, and preserve the instance specific settings, you should do
the same during upgrades and execute multiple calls to
clusterctl upgrade apply, each one with different environment
For instance, in case of a management cluster with n>1 instances of an infrastructure provider, and only one instance of Cluster API core provider, bootstrap provider and control plane provider, you should:
clusterctl upgrade apply for the core provider, the bootstrap provider and the control plane provider;
this can be achieved by using the
--control-plane flags followed by the upgrade target
for each one of those providers, e.g.
clusterctl upgrade apply --management-group capi-system/cluster-api \ --core capi-system/cluster-api:v0.3.1 \ --bootstrap capi-kubeadm-bootstrap-system/kubeadm:v0.3.1 \ --control-plane capi-kubeadm-control-plane-system/kubeadm:v0.3.1
clusterctl upgrade apply for each infrastructure provider instance, using the
taking care to provide different environment variables for each call (as in the initial setup), e.g.
Set the environment variables for instance 1 and then run:
clusterctl upgrade apply --management-group capi-system/cluster-api \ --infrastructure instance1/docker:v0.3.1
Afterwards, set the environment variables for instance 2 and then run:
clusterctl upgrade apply --management-group capi-system/cluster-api \ --infrastructure instance2/docker:v0.3.1