overridden-type-provider

Overridden Type and Provider

When projected into the workload, the binding must contain a type entry and should contain a provider entry. If the Secret doesn't contain a type or provider, or contains the wrong values, they can be overridden for the binding.

In this sample, we'll use a Kubernetes Job to dump the environment to the logs and exit.

Setup

If not already installed, install the ServiceBinding CRD and controller.

Deploy

Like Pods, Kubernetes Jobs are immutable after they are created. We need to make sure the ServiceBindings are fully configured before the workload is created.

Apply the ProvisionedService and ServiceBinding:

kubectl apply -f ./samples/overridden-type-provider/service.yaml -f ./samples/overridden-type-provider/service-binding.yaml

Check on the status of the ServiceBinding:

kubectl get servicebinding -l sample=overridden-type-provider -oyaml

For each service binding, the ServiceAvailable condition should be True and the ProjectionReady condition False.

...
  conditions:
  - lastTransitionTime: "2021-07-23T16:46:58Z"
    message: jobs.batch "overridden-type-provider" not found
    reason: ProjectionReadyWorkloadMissing
    status: "False"
    type: Ready
  - lastTransitionTime: "2021-07-23T16:46:58Z"
    message: ""
    reason: Available
    status: "True"
    type: ServiceAvailable
  - lastTransitionTime: "2021-07-23T16:46:58Z"
    message: jobs.batch "overridden-type-provider" not found
    reason: WorkloadMissing
    status: "False"
    type: ProjectionReady

Create the workload Job:

kubectl apply -f ./samples/overridden-type-provider/workload.yaml

Understand

Each ServiceBinding resource defines an environment variable that is projected into the workload in addition to the binding volume mount.

kubectl describe job overridden-type-provider

...
Environment:
  SERVICE_BINDING_ROOT:  /bindings
  BOUND_PROVIDER:         (v1:metadata.annotations['internal.bindings.labs.vmware.com/projection-717760b0e7853de4a23bffadf9d02d6109c6ad2e-provider'])
  BOUND_TYPE:             (v1:metadata.annotations['internal.bindings.labs.vmware.com/projection-717760b0e7853de4a23bffadf9d02d6109c6ad2e-type'])
...

The job dumps the environment to the log and then exits. We should see our injected environment variable as well as other variable commonly found in Kubernetes containers.

Inspect the logs from the job:

kubectl logs -l job-name=overridden-type-provider --tail 100

...
SERVICE_BINDING_ROOT=/bindings
BOUND_PROVIDER=overridden-provider
BOUND_TYPE=overridden-type
...

Play

Try changing the .spec.type or .spec.provider fields on the ServiceBinding, or return them to the original values (empty string). Remember that Jobs are immutable after they are created, so you'll need to delete and recreate the Job to see the additional binding.

Alternatively, define a Deployment and update each binding to target the new Deployment. Since Deployments are mutable, each service binding that is added or removed will be reflected on the Deployment and trigger the rollout of a new ReplicaSet.