Side container to keep track of docker stats during GCB build steps

cloudbuild.yaml

steps:
# Run docker stats in the background.
# --no-stream is used in order to print the stats on different lines.
- name: 'gcr.io/cloud-builders/docker'
  args:
  - 'run'
  - '-d'
  - '--name=docker-stats'
  - '--volume=/var/run/docker.sock:/var/run/docker.sock'
  - '--entrypoint=/bin/bash'
  - 'gcr.io/cloud-builders/docker'
  - '-c'
  - 'while true; do docker stats --no-stream; sleep 1; done'

# Simulate some CPU intensive step.
- name: 'ubuntu'
  entrypoint: 'bash'
  args:
  - '-c'
  - |
    apt-get update
    apt-get install -y stress
    stress --cpu 1 --timeout 10

# Show logs from the docker stats command.
- name: 'gcr.io/cloud-builders/docker'
  args: ['logs', 'docker-stats']