Set the hostname for containers and functions

[alexellis]

Signed-off-by: Alex Ellis (OpenFaaS Ltd) alexellis2@gmail.com

Description

Set the hostname for containers and functions

Motivation and Context

By setting the hostname, the container will resolve to its
name instead of just localhost.

How Has This Been Tested?

CI, manual testing to follow

Before:

pi@faasd-pi:~ $ sudo ctr -n openfaas-fn  t exec --exec-id 2398  nodeinfo hostname
faasd-pi

After:

pi@k4s-1:~ $ sudo ctr -n openfaas-fn  t exec --exec-id 22954 nodeinfo hostname
nodeinfo

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)