Tech Challenge

A container sets securityContext.readOnlyRootFilesystem: true, as shown. Its process needs to write temporary files to /tmp. What is the effect of this setting, and what must you add for the writes to succeed?

containers:
- name: app
  image: myapp:1.0
  securityContext:
    readOnlyRootFilesystem: true
  volumeMounts:
  - name: scratch
    mountPath: /tmp
volumes:
- name: scratch
  emptyDir: {}