Add support for namespace to commands

[alexellis]

Signed-off-by: Alex Ellis (OpenFaaS Ltd) [email protected]

Description

Add support for namespace to commands

Motivation and Context

This is being added for #511, so that the list, update, delete
and read endpoints all can take an optional namespace override.

How Has This Been Tested?

Tested with k3s 1.15 and two namespaces. Also tested that kube-
system is blocked for those commands.

alext:faas-netes alex$ kubectl get deploy -n openfaas-fn
NAME   READY   UP-TO-DATE   AVAILABLE   AGE
cows   1/1     1            1           38h
alext:faas-netes alex$ kubectl get deploy -n fn
NAME       READY   UP-TO-DATE   AVAILABLE   AGE
nodeinfo   2/2     2            2           38h
alext:faas-netes alex$ 
alext:faas-netes alex$ curl -s $AUTH/system/functions?namespace=openfaas-fn |jq
[
  {
    "name": "cows",
    "image": "alexellis2/ascii-cows-openfaas:0.1",
    "invocationCount": 0,
    "replicas": 1,
    "envProcess": "",
    "availableReplicas": 1,
    "labels": {
      "faas_function": "cows"
    },
    "annotations": {
      "prometheus.io.scrape": "false"
    },
    "namespace": "openfaas-fn"
  }
]
alext:faas-netes alex$ curl -s $AUTH/system/functions?namespace=fn |jq
[
  {
    "name": "nodeinfo",
    "image": "functions/nodeinfo:latest",
    "invocationCount": 0,
    "replicas": 2,
    "envProcess": "",
    "availableReplicas": 2,
    "labels": {
      "com.openfaas.scale.max": "5",
      "com.openfaas.scale.min": "2",
      "faas_function": "nodeinfo"
    },
    "annotations": {
      "prometheus.io.scrape": "false"
    },
    "namespace": "fn"
  }
]

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)