Adds CRUD for namespaces and moves namespace for delete/
scale to the body from the query string.
Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alex@openfaas.com>
Introduces a single-flight call to a function's health
endpoint to verify that it is registered with an Istio
sidecar (Envoy) before letting the invocation through.
Results are cached for 5 seconds, before a probe is
required again.
Tested without Istio, with probe_functions environment
variable set to true, I saw a probe execute in the logs.
Fixes: #1721 for Istio users.
Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alex@openfaas.com>
