uks-controller

Custom Kubernetes controller designed to view VMs from UpCloud API using kubectl

Quickstart

Setup UpCloud API Credentials

export UPCLOUD_API_USERNAME=
export UPCLOUD_API_PASSWORD=

Pull vendored upcloud-go-api

git submodule update --recursive

Build and run it locally

make install run

Configuration

Syncing interval can be configured by --sync-interval parameter when the controller is started. By default, VMs are being synced every 15 seconds.

Implementation

Number of currently syncing UpCloud VMs are available via Prometheus interface (metric name: virtual_machine_syncing_vms).

Further development

• Unit testing
• Kubernetes events
• Enable metrics protection

Logging

• V=1 - we want always see it
• V=2 - a bit more verbosity
• V=3 - we are debugging the controller, loads of big structures shall we logged

The logging itself is controller by -zap-log-level argument, e.g. -zap-log-level=3 gives you plenty of information on state changes.

Assumptions

UpCloud API credentials are set in os.Environ

Observations

• Creating Machine API Key isn't straight-forward
• Creating a sub-user
  • Create subaccount
    • is grayed out without any explanation unless free trial is started (shall indicate what's wrong)
• Having UpCloudLtd as a github org name makes a path like this /go/pkg/mod/github.com/!up!cloud!ltd. Those ! make life a bit worse. Try to cd to this directory. And do it again.

References

• https://sdk.operatorframework.io/docs/building-operators/golang/quickstart/
• https://github.com/UpCloudLtd/upcloud-go-api
• https://developers.upcloud.com/1.3/
• https://upcloud.com/resources/tutorials/getting-started-upcloud-api
• https://upcloud.com/docs/getting-started/free-trial/
• https://github.com/kubernetes/community/blob/master/contributors/devel/sig-instrumentation/logging.md#what-method-to-use
• https://book.kubebuilder.io/
• https://go.dev/doc/modules/gomod-ref