feature: supported to use host name in upstream

bin/apisix

@@ -150,7 +150,7 @@ http {
 
     lua_socket_log_errors off;
 
-    resolver ipv6=off local=on;
+    resolver {% for _, dns_addr in ipairs(dns_resolver or {}) do %} {*dns_addr*} {% end %} ipv6=off local=on;
     resolver_timeout 5;
 
     lua_http10_buffering off;

conf/config.yaml

@@ -29,6 +29,8 @@ apisix:
   #   udp:                        # UDP proxy port list
   #     - 9200
   #     - 9211
+  dns_resolver:                   # use 114.114.114.114 as default DNS resolver, disable IPv6 and enable local DNS.
+    - 114.114.114.114
 
 etcd:
   host: "http://127.0.0.1:2379"   # etcd address

conf/nginx.conf

@@ -38,7 +38,7 @@ http {
 
     lua_socket_log_errors off;
 
-    resolver ipv6=off local=on;
+    resolver 114.114.114.114 ipv6=off local=on;
     resolver_timeout 5;
 
     lua_http10_buffering off;

doc/architecture-design-cn.md

@@ -231,7 +231,7 @@ APISIX 的 Upstream 除了基本的复杂均衡算法选择外，还支持对上
 |名字    |可选|说明|
 |-------         |-----|------|
 |type            |必需|`roundrobin` 支持权重的负载，`chash` 一致性哈希，两者是二选一的|
-|nodes           |必需|哈希表，内部元素的 key 是上游机器地址列表（IP+Port 方式），value 则是节点的 weight。无论对于 `roundrobin` 还是 `chash` 算法，上游节点的选择都依赖它。特别的，权重值为 `0` 有特殊含义，通常代表该上游节点失效，永远不希望被选中。|
+|nodes           |必需|哈希表，内部元素的 key 是上游机器地址列表，格式为`地址 + Port`，其中地址部分可以是 IP 也可以是域名，比如 `192.168.1.100:80`、`foo.com:80`等。value 则是节点的权重，特别的，当权重值为 `0` 有特殊含义，通常代表该上游节点失效，永远不希望被选中。|
 |key             |必需|该选项只有类型是 `chash` 才有效。根据 `key` 来查找对应的 node `id`，相同的 `key` 在同一个对象中，永远返回相同 id|
 |checks          |可选|配置健康检查的参数，详细可参考[health-check](health-check.md)|
 |retries         |可选|使用底层的 Nginx 重试机制将请求传递给下一个上游，默认不启用重试机制|
@@ -248,8 +248,8 @@ curl http://127.0.0.1:9080/apisix/admin/upstreams/1 -X PUT -d '
     "type": "roundrobin",
     "nodes": {
         "127.0.0.1:80": 1,
-        "127.0.0.2:80": 1,
-        "127.0.0.3:80": 1
+        "127.0.0.2:80": 2,
+        "foo.com:80": 3
     }
 }'
 
@@ -259,7 +259,7 @@ curl http://127.0.0.1:9080/apisix/admin/upstreams/2 -X PUT -d '
     "key": "remote_addr",
     "nodes": {
         "127.0.0.1:80": 1,
-        "127.0.0.2:80": 1
+        "foo.com:80": 2
     }
 }'
 ```

lua/apisix.lua

@@ -1,24 +1,32 @@
 -- Copyright (C) Yuansheng Wang
 
-local require = require
-local core = require("apisix.core")
-local plugin = require("apisix.plugin")
+local require       = require
+local core          = require("apisix.core")
+local plugin        = require("apisix.plugin")
 local service_fetch = require("apisix.http.service").get
-local admin_init = require("apisix.admin.init")
-local get_var = require("resty.ngxvar").fetch
-local router = require("apisix.router")
-local ngx = ngx
-local get_method = ngx.req.get_method
-local ngx_exit = ngx.exit
-local ngx_ERROR = ngx.ERROR
-local math = math
-local error = error
-local ngx_var = ngx.var
-local ipairs = ipairs
+local admin_init    = require("apisix.admin.init")
+local get_var       = require("resty.ngxvar").fetch
+local router        = require("apisix.router")
+local ipmatcher     = require("resty.ipmatcher")
+local ngx           = ngx
+local get_method    = ngx.req.get_method
+local ngx_exit      = ngx.exit
+local ngx_ERROR     = ngx.ERROR
+local math          = math
+local error         = error
+local ngx_var       = ngx.var
+local ipairs        = ipairs
+local pairs         = pairs
+local tostring      = tostring
 local load_balancer
 
 
-local _M = {version = 0.2}
+local parsed_domain = core.lrucache.new({
+    ttl = 300, count = 512
+})
+
+
+local _M = {version = 0.3}
 
 
 function _M.http_init()
@@ -143,6 +151,70 @@ function _M.http_ssl_phase()
 end
 
 
+local function parse_domain_in_up(up, ver)
+    local local_conf = core.config.local_conf()
+    local dns_resolver = local_conf and local_conf.apisix and
+                         local_conf.apisix.dns_resolver
+    local new_nodes = core.table.new(0, 8)
+
+    for addr, weight in pairs(up.value.nodes) do
+        local host, port = core.utils.parse_addr(addr)
+        if not ipmatcher.parse_ipv4(host) and
+           not ipmatcher.parse_ipv6(host) then
+            local ip_info = core.utils.dns_parse(dns_resolver, host)
+            core.log.info("parse addr: ", core.json.delay_encode(ip_info),
+                          " resolver: ", core.json.delay_encode(dns_resolver),
+                          " addr: ", addr)
+            if ip_info and ip_info.address then
+                new_nodes[ip_info.address .. ":" .. port] = weight
+                core.log.info("dns resolver domain: ", host, " to ",
+                              ip_info.address)
+            end
+        else
+            new_nodes[addr] = weight
+        end
+    end
+
+    up.dns_value = core.table.clone(up.value)
+    up.dns_value.nodes = new_nodes
+    core.log.info("parse upstream which contain domain: ",
+                  core.json.delay_encode(up))
+    return up
+end
+
+
+local function parse_domain_in_route(route, ver)
+    local local_conf = core.config.local_conf()
+    local dns_resolver = local_conf and local_conf.apisix and
+                         local_conf.apisix.dns_resolver
+    local new_nodes = core.table.new(0, 8)
+
+    for addr, weight in pairs(route.value.upstream.nodes) do
+        local host, port = core.utils.parse_addr(addr)
+        if not ipmatcher.parse_ipv4(host) and
+           not ipmatcher.parse_ipv6(host) then
+            local ip_info = core.utils.dns_parse(dns_resolver, host)
+            core.log.info("parse addr: ", core.json.delay_encode(ip_info),
+                          " resolver: ", core.json.delay_encode(dns_resolver),
+                          " addr: ", addr)
+            if ip_info and ip_info.address then
+                new_nodes[ip_info.address .. ":" .. port] = weight
+                core.log.info("dns resolver domain: ", host, " to ",
+                              ip_info.address)
+            end
+        else
+            new_nodes[addr] = weight
+        end
+    end
+
+    route.dns_value = core.table.deepcopy(route.value)
+    route.dns_value.upstream.nodes = new_nodes
+    core.log.info("parse route which contain domain: ",
+                  core.json.delay_encode(route))
+    return route
+end
+
+
 do
     local upstream_vars = {
         uri        = "upstream_uri",
@@ -226,7 +298,7 @@ function _M.http_access_phase()
         end
 
         local changed
-        route, changed = plugin.merge_service_route(service, route)
+        route, changed = plugin.merge_route(service, route)
         api_ctx.matched_route = route
 
         if changed then
@@ -240,13 +312,28 @@ function _M.http_access_phase()
             api_ctx.conf_version = service.modifiedIndex
             api_ctx.conf_id = service.value.id
         end
-
     else
         api_ctx.conf_type = "route"
         api_ctx.conf_version = route.modifiedIndex
         api_ctx.conf_id = route.value.id
     end
 
+    local up_id = route.value.upstream_id
+    if up_id then
+        local upstreams_etcd = core.config.fetch_created_obj("/upstreams")
+        if upstreams_etcd then
+            local upstream = upstreams_etcd:get(tostring(up_id))
+            if upstream.has_domain then
+                parsed_domain(upstream, api_ctx.conf_version,
+                              parse_domain_in_up, upstream)
+            end
+        end
+
+    elseif route.has_domain then
+        route = parsed_domain(route, api_ctx.conf_version,
+                              parse_domain_in_route, route)
+    end
+
     local plugins = core.tablepool.fetch("plugins", 32, 0)
     api_ctx.plugins = plugin.filter(route, plugins)
 
@@ -288,7 +375,7 @@ function _M.grpc_access_phase()
         end
 
         local changed
-        route, changed = plugin.merge_service_route(service, route)
+        route, changed = plugin.merge_route(service, route)
         api_ctx.matched_route = route
 
         if changed then

lua/apisix/balancer.lua

@@ -1,20 +1,20 @@
 local healthcheck = require("resty.healthcheck")
 local roundrobin  = require("resty.roundrobin")
 local resty_chash = require("resty.chash")
-local balancer = require("ngx.balancer")
-local core = require("apisix.core")
-local sub_str = string.sub
-local find_str = string.find
-local upstreams_etcd
-local error = error
-local str_char = string.char
-local str_gsub = string.gsub
-local pairs = pairs
-local tonumber = tonumber
-local tostring = tostring
-local set_more_tries = balancer.set_more_tries
+local balancer    = require("ngx.balancer")
+local core        = require("apisix.core")
+local sub_str     = string.sub
+local find_str    = string.find
+local error       = error
+local str_char    = string.char
+local str_gsub    = string.gsub
+local pairs       = pairs
+local tonumber    = tonumber
+local tostring    = tostring
+local set_more_tries   = balancer.set_more_tries
 local get_last_failure = balancer.get_last_failure
-local set_timeouts = balancer.set_timeouts
+local set_timeouts     = balancer.set_timeouts
+local upstreams_etcd
 
 
 local module_name = "balancer"
@@ -170,8 +170,9 @@ local function pick_server(route, ctx)
     core.log.info("ctx: ", core.json.delay_encode(ctx, true))
     local healthcheck_parent = route
     local up_id = route.value.upstream_id
-    local upstream = route.value.upstream
-    if not up_id and not upstream then
+    local up_conf = (route.dns_value and route.dns_value.upstream)
+                    or route.value.upstream
+    if not up_id and not up_conf then
         return nil, nil, "missing upstream configuration"
     end
 
@@ -184,40 +185,40 @@ local function pick_server(route, ctx)
                              .. "upstream information"
         end
 
-        local upstream_obj = upstreams_etcd:get(tostring(up_id))
-        if not upstream_obj then
+        local up_obj = upstreams_etcd:get(tostring(up_id))
+        if not up_obj then
             return nil, nil, "failed to find upstream by id: " .. up_id
         end
-        core.log.info("upstream: ", core.json.delay_encode(upstream_obj))
+        core.log.info("upstream: ", core.json.delay_encode(up_obj))
 
-        healthcheck_parent = upstream_obj
-        upstream = upstream_obj.value
-        version = upstream_obj.modifiedIndex
-        key = upstream.type .. "#upstream_" .. up_id
+        healthcheck_parent = up_obj
+        up_conf = up_obj.dns_value or up_obj.value
+        version = up_obj.modifiedIndex
+        key = up_conf.type .. "#upstream_" .. up_id
 
     else
         version = ctx.conf_version
-        key = upstream.type .. "#route_" .. route.value.id
+        key = up_conf.type .. "#route_" .. route.value.id
     end
 
-    local checker = fetch_healthchecker(upstream, healthcheck_parent, version)
-    local retries = upstream.retries
+    local checker = fetch_healthchecker(up_conf, healthcheck_parent, version)
+    local retries = up_conf.retries
     if retries and retries > 0 then
         ctx.balancer_try_count = (ctx.balancer_try_count or 0) + 1
         if checker and ctx.balancer_try_count > 1 then
             local state, code = get_last_failure()
             if state == "failed" then
                 if code == 504 then
                     checker:report_timeout(ctx.balancer_ip, ctx.balancer_port,
-                                           upstream.checks.host)
+                                           up_conf.checks.host)
                 else
                     checker:report_tcp_failure(ctx.balancer_ip,
-                        ctx.balancer_port, upstream.checks.host)
+                        ctx.balancer_port, up_conf.checks.host)
                 end
 
             else
                 checker:report_http_status(ctx.balancer_ip, ctx.balancer_port,
-                                           upstream.checks.host, code)
+                                           up_conf.checks.host, code)
             end
         end
 
@@ -231,7 +232,7 @@ local function pick_server(route, ctx)
     end
 
     local server_picker = lrucache_server_picker(key, version,
-                            create_server_picker, upstream, checker)
+                            create_server_picker, up_conf, checker)
     if not server_picker then
         return nil, nil, "failed to fetch server picker"
     end
@@ -241,8 +242,8 @@ local function pick_server(route, ctx)
         return nil, nil, "failed to find valid upstream server" .. err
     end
 
-    if upstream.timeout then
-        local timeout = upstream.timeout
+    if up_conf.timeout then
+        local timeout = up_conf.timeout
         local ok, err = set_timeouts(timeout.connect, timeout.send,
                                      timeout.read)
         if not ok then
@@ -280,9 +281,27 @@ end
 function _M.init_worker()
     local err
     upstreams_etcd, err = core.config.new("/upstreams", {
-                                automatic = true,
-                                item_schema = core.schema.upstream
-                            })
+            automatic = true,
+            item_schema = core.schema.upstream,
+            filter = function(upstream)
+                upstream.has_domain = false
+                if not upstream.value then
+                    return
+                end
+
+                for addr, _ in pairs(upstream.value.nodes or {}) do
+                    local host = core.utils.parse_addr(addr)
+                    if not core.utils.parse_ipv4(host) and
+                       not core.utils.parse_ipv6(host) then
+                        upstream.has_domain = true
+                        break
+                    end
+                end
+
+                core.log.info("filter upstream: ",
+                              core.json.delay_encode(upstream))
+            end,
+        })
     if not upstreams_etcd then
         error("failed to create etcd instance for fetching upstream: " .. err)
         return