[MESOS-6282] CNI isolator should print plugin's stderr

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.1.0
• Component/s: containerization, network
• Target Version/s: 1.1.0
• Assignee: Avinash Sridharan
• Reporter: Dan Osborne
• Shepherd: Jie Yu
• Created: 29/Sep/16 18:10
• Updated: 26/Apr/17 16:53
• Resolved: 18/Oct/16 00:58

Description

It's quite difficult for both Operators and CNI plugin developers to diagnose CNI plugin errors in production or in test when the only error information available is the stdout error string returned by the plugin (assuming it managed to even print its correctly formatted text to stdout).

Many CNI plugins print logging information to stderr, as per the CNI spec:

In addition, stderr can be used for unstructured output such as logs.

Therefore, I propose the Mesos CNI Isolator capture the CNI plugin's stderr output and log it to the Agent Logs, for easier diagnosis.