Provide an API to do scale up operation, leave the container
monitoring to orchestrator underlay, although k8s already supports
HPA, but we should not rely on specific container orchestrator
capability for general purpose.
Partially implements: blueprint qingling-autoscaling
This is part-1 of jobs support in Qinling.
With job API, users can create a job with an existing function
that can be ran in cron job's fashion, but the job definition
has more capabilities than cron.
When a package function is executed, a service url is cached so it's
faster when function is executed again. But this will lead to problem
if function is never executed for a long time.
This patch add an expiry machanism which will release resources in
Allow user to create function using her own docker image including
all the code and dependencies inside. The image needs to have an
script running as entry point, expecting user's input as params.
This allow users to execute functions written in any language.