[MESOS-9658] Make command-line and/or environment variables be able to unset a flag.

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Labels: integration
• Assignee: Unassigned
• Reporter: Chun-Hung Hsiao
• Created: 15/Mar/19 23:34
• Updated: 29/Apr/19 09:25

Description

Currently if a Mesos master/agent command-line flag is of type Option, the only way to leave it as None is to unset the corresponding MESOS_ environment variable and don't specify the flag. Although this works, it would be nice if the user could:
1. Override environment variable through command-line flags, e.g. --feature_flag=none.
2. Override environment variable with another value, e.g., MESOS_FEATURE_FLAG=none. This is especially useful if users are managing Mesos through systemd and specifying flags through environment files.