[DISCUSS] How to add a single upstream node to the upstream list via the Admin API?

[YuanSheng Wang]

Hi:

For the upstream node list, we should allow new nodes to be added to it via
Admin API.
Users only need to provide new node information.

I think we can use PATCH + uri, with an extra parameter to indicate the
data merge method: full replacement or partial modification.

Here is an example:

*Old data:*

    {
        "nodes": {
            "127.0.0.1:8080": 1
        },
        "type": "roundrobin",
        "desc": "new upstream"
    }

*Add new node:*

    curl http://****/apisix/admin/upstreams/1/nodes?merge=partial -X PATCH \
        -d '{"127.0.0.1:8081":3}'

*Current data:*

    {
        "nodes": {
            "127.0.0.1:8080": 1,
            "127.0.0.1:8081": 3
        },
        "type": "roundrobin",
        "desc": "new upstream"
    }


-- 
*MembPhis*
My github: https://github.com/membphis
Apache APISIX: https://github.com/apache/incubator-apisix