By default sidecar timeout to authenticate to Keystone
is set to 5 seconds.
In most of the cases 5 seconds is enough but depending
the environment, the authentication complexity, etc...
it could be too short.
There is a limitation for loading modules directly from a zip file:
"ZIP import of dynamic modules (.pyd, .so) is disallowed." which
makes most of python libs including C extentions not work. So we have
to extract the zip before executing the function.
Split function package download functionality into a separate
container, so that it will be easy to add additional runtime support.
I was planning to use kubernetes new verion apps api in qinling, but
failed because the kubernetes client in global requirement is not
updated yet, so I comment the code out in case we use them in future.