Prometheus in Omnibus is unable to perform Kubernetes SD

I manually attempted to enable Kubernetes SD on the packaged version of Prometheus, by editing prometheus.yml and reloading the config. The config has taken effect, however I am getting errors in the log.

Is there some reason the packaged version of Prometheus is unable to retrieve environment variables?

2017-02-03_03:22:52.38914 time="2017-02-03T03:22:52Z" level=error msg="Cannot create Kubernetes discovery: unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined" source="discovery.go:84" 

In checking the environment of the container, these are defined:

KUBERNETES_SERVICE_PORT=443
KUBERNETES_SERVICE_HOST=10.15.240.1

The configuration is here:

global:
  scrape_interval: 15s
  scrape_timeout: 15s

scrape_configs:
  - job_name: prometheus
    static_configs:
      - targets: ['localhost:9090']
  - job_name: node
    static_configs:
      - targets: ['localhost:9100']
  - job_name: 'kubernetes-nodes'
    scheme: https
    tls_config:
      ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      insecure_skip_verify: true
    bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
    kubernetes_sd_configs:
    - role: node
    relabel_configs:
    - action: labelmap
      regex: __meta_kubernetes_node_label_(.+)