KAR injector support for Camel-K

[tardieu]

To deploy Camel-K integrations using kubectl with need yaml such as:

apiVersion: v1
kind: Pod
metadata:
  name: stock-source
spec:
  containers:
  - name: stock-source
    image: localhost:5000/kar/kar-examples-stock-source
    env:
    - name: KAFKA_BROKERS
      valueFrom:
        secretKeyRef:
          name: kar.ibm.com.runtime-config
          key: kafka_brokers

See https://github.com/IBM/kar/blob/main/examples/camel-k/deploy/stocks.yaml.

We could extend the mutating webhook to permit something like:

apiVersion: v1
kind: Pod
metadata:
  name: stock-source
  annotations:
    kar.ibm.com/runtime: camel
spec:
  containers:
  - name: stock-source
    image: localhost:5000/kar/kar-examples-stock-source

[dgrove-oss]

How much control do we have over the container that needs the runtime config? What we are actually doing in the sidecar injector is injecting a VolumeMount of the kar.ibm.com.runtime-config secret. Doing the same for the camel container would be significantly simpler than mucking with the environment more directly.