Dashboard api proxy to api engine, proxy_header host doesn't include port info

[hightall]

Expected Behavior

Api proxy from dashboard to api engine, should include port info, so that when api engine use build_absolute_uri can get the port info, and generate the right url.

Current Behavior

Such as get agent config url path, http://9.59.196.20/engine/media/config_files/63a4e2b6-a61b-4537-9558-4a33789b2222/bf08eecabf0b7afee5b25e0363e9c061.zip
port is ignored ,but the server is not running on 80 port, it's really port is 8085, so agent can't download the config file.

Possible Solution

Add api engine service port into proxy_set_header Host $host:SERVICE_PORT

Steps to Reproduce

1. make start
2. create new agent
3. create a ca node, will keep deploying.

Context (Environment)

Detailed Description or log

Traceback (most recent call last):
  File "main.py", line 9, in <module>
    create_node()
  File "/app/operations/create_node.py", line 161, in create_node
    _create_fabric_node()
  File "/app/operations/create_node.py", line 84, in _create_fabric_node
    k8s_client = get_k8s_client()
  File "/app/utils/__init__.py", line 30, in get_k8s_client
    k8s_client = KubernetesClient(config_file=k8s_config)
  File "/app/utils/client.py", line 16, in __init__
    config.load_kube_config(config_file)
  File "/usr/local/lib/python3.6/site-packages/kubernetes/config/kube_config.py", line 546, in load_kube_config
    config_persister=config_persister)
  File "/usr/local/lib/python3.6/site-packages/kubernetes/config/kube_config.py", line 503, in _get_kube_config_loader_for_yaml_file
    with open(filename) as f:
FileNotFoundError: [Errno 2] No such file or directory: '/app/.kube/config'

Possible Implementation