DockerContainerFactory - no healthy invokers under TravisCI tests

[dgrove-oss]

After the upstream change apache/openwhisk#4041, the DockerContainerFactory in Kubernetes started failing in TravisCI . In particular, the /invokers/healthy/count route on the controller always returns 0 because the invoker never transitions from Unhealthy to Healthy.

The problem appears to be that log collection of the InvokerHealth action fails, resulting in the container being removed without a response being sent back to the controller. The failure with log collection may be limited to kubeadm-dind clusters on ubuntu 16.04 (log collection does not fail using Kubernetes on Docker for Mac).

This is likely an existing bug that was masked because before 4041, an activeack for the HealthAction was returned before log collection failed.

[dgrove-oss]

Yep, specific to docker-in-docker kubernetes clusters. We need to mount /dind/docker/containers instead of /var/lib/docker/containers in the invoker pod.