Enable HTTP probe by default

[alexellis]

Signed-off-by: Alex Ellis alexellis2@gmail.com

Description

Enable HTTP probe by default

Motivation and Context

• I have raised an issue to propose this change (required)

Fixes #466

This will reduce user-facing CPU usage.

Change also increases function polling time to 2s to reduce
the CPU overhead. Users can set this to 1s for faster cold-starts.

How Has This Been Tested?

Tested with common function store images. Some older images will need to be rebuilt by the user.

I would recommend that we introduce a flag that can set the probe type on a per-function basis for backwards-compatibility.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.

[alexellis]

Thanks both 👍