feat(upstream): filter nodes in upstream with metadata

apisix/discovery/consul/init.lua

@@ -511,11 +511,12 @@ function _M.connect(premature, consul_server, retry_delay)
                 local nodes = up_services[service_name]
                 local nodes_uniq = {}
                 for _, node in ipairs(result.body) do
-                    if not node.Service then
+                    local service = node.Service
+                    if not service then
                         goto CONTINUE
                     end
 
-                    local svc_address, svc_port = node.Service.Address, node.Service.Port
+                    local svc_address, svc_port, metadata = service.Address, service.Port, service.Meta
                     -- Handle nil or 0 port case - default to 80 for HTTP services
                     if not svc_port or svc_port == 0 then
                         svc_port = 80
@@ -532,7 +533,8 @@ function _M.connect(premature, consul_server, retry_delay)
                         core.table.insert(nodes, {
                             host = svc_address,
                             port = tonumber(svc_port),
-                            weight = default_weight,
+                            weight = metadata and metadata.weight or default_weight,
+                            metadata = metadata
                         })
                         nodes_uniq[service_id] = true
                     end

apisix/upstream.lua

@@ -278,6 +278,35 @@ local function fill_node_info(up_conf, scheme, is_stream)
     return true
 end
 
+local function match_metadata_filters(inst, filters)
+    local metadata = inst.metadata or {}
+    for _, f in ipairs(filters) do
+        local key = f.key
+        local allowed_vals = f.allowed_vals
+        local val = metadata[key]
+        local matched = false
+        for _, allowed in ipairs(allowed_vals) do
+            if val == allowed then
+                matched = true
+                break
+            end
+        end
+        if not matched then
+            return false
+        end
+    end
+    return true
+end
+
+local function match_nodes_by_metadata(nodes, filters)
+    local result = {}
+    for _, node in ipairs(nodes) do
+        if match_metadata_filters(node, filters) then
+            core.table.insert(result, node)
+        end
+    end
+    return result
+end
 
 function _M.set_by_route(route, api_ctx)
     if api_ctx.upstream_conf then
@@ -310,6 +339,14 @@ function _M.set_by_route(route, api_ctx)
             return HTTP_CODE_UPSTREAM_UNAVAILABLE, "no valid upstream node: " .. (err or "nil")
         end
 
+        if up_conf.metadata_match then
+            new_nodes = match_nodes_by_metadata(new_nodes, up_conf.metadata_match)
+            if #new_nodes == 0 then
+                return HTTP_CODE_UPSTREAM_UNAVAILABLE, "no matched node filterd by metadata_match"
+            end
+            core.log.info("filterd by metadata_match: ", core.json.delay_encode(new_nodes, true))
+        end
+
         local same = upstream_util.compare_upstream_node(up_conf, new_nodes)
         if not same then
             if not up_conf._nodes_ver then

t/discovery/consul.t

@@ -781,3 +781,61 @@ location /sleep {
     qr//
 ]
 --- ignore_error_log
+
+=== TEST 16: test metadata_match with consul discovery
+--- yaml_config
+apisix:
+    node_listen: 1984
+    config_center: yaml
+    discovery:
+        consul:
+            servers:
+              - http://127.0.0.1:8500
+routes:
+  -
+    uri: /test_metadata_match
+    upstream:
+      service_name: mock-service
+      type: roundrobin
+      discovery_type: consul
+      metadata_match:
+        version:
+          - "v2"
+
+--- config
+location /v1/agent {
+    proxy_pass http://127.0.0.1:8500;
+}
+location /test_metadata_match {
+    content_by_lua_block {
+        local server = ngx.var.server_addr or "unknown"
+        ngx.say("Upstream server handling request: ", server)
+    }
+}
+--- timeout: 5
+--- pipelined_requests eval
+[
+    "PUT /v1/agent/service/register\n" . "{\"ID\":\"mock-node-v1\",\"Name\":\"mock-service\",\"Address\":\"127.0.0.1\",\"Port\":1984,\"Meta\":{\"version\":\"v1\",\"weight\":\"1\"},\"EnableTagOverride\":false,\"Weights\":{\"Passing\":10,\"Warning\":1}}",
+    "PUT /v1/agent/service/register\n" . "{\"ID\":\"mock-node-v2\",\"Name\":\"mock-service\",\"Address\":\"127.0.0.2\",\"Port\":1984,\"Meta\":{\"version\":\"v2\",\"weight\":\"2\"},\"EnableTagOverride\":false,\"Weights\":{\"Passing\":10,\"Warning\":1}}",
+
+    "GET /test_metadata_match?run1",
+    "GET /test_metadata_match?run2",
+    "GET /test_metadata_match?run3",
+
+    "PUT /v1/agent/service/deregister/mock-node-v1",
+    "PUT /v1/agent/service/deregister/mock-node-v2"
+]
+--- response_body_like eval
+[
+    qr//,
+    qr//,
+
+    qr/127.0.0.2/,
+    qr/127.0.0.2/,
+    qr/127.0.0.2/,
+
+    qr//,
+    qr//
+]
+--- no_error_log
+[error]

t/node/upstream-discovery.t

@@ -508,3 +508,64 @@ qr/compare upstream nodes by value|fill node info for upstream/
 fill node info for upstream
 compare upstream nodes by value
 fill node info for upstream
+
+=== TEST 11: test metadata_match for upstream nodes selection
+--- log_level: debug
+--- apisix_yaml
+routes:
+  -
+    uri: /hello
+    upstream:
+      type: roundrobin
+      nodes:
+        "127.0.0.1:1980":
+          weight: 1
+          metadata:
+            version: v1
+        "127.0.0.2:1980":
+          weight: 1
+          metadata:
+            version: v2
+      metadata_match:
+        version: v2
+--- config
+    location /t {
+        content_by_lua_block {
+            local discovery = require("apisix.discovery.init").discovery
+            -- mock nodes with metadata
+            discovery.mock = {
+                nodes = function()
+                    return {
+                        {host = "127.0.0.1", port = 1980, weight = 1, metadata = {version = "v1"}},
+                        {host = "127.0.0.2", port = 1980, weight = 1, metadata = {version = "v2"}},
+                    }
+                end
+            }
+
+            local http = require "resty.http"
+            local uri = "http://127.0.0.1:" .. ngx.var.server_port .. "/hello"
+            local httpc = http.new()
+
+            -- do 5 requests and expect upstream node with metadata.version == v2 (127.0.0.2)
+            for i = 1, 5 do
+                local res = httpc:request_uri(uri, {method = "GET", keepalive = false})
+                if res.status ~= 200 then
+                    ngx.say("request failed: ", res.status)
+                    return
+                end
+                if not string.find(res.body, "127.0.0.2") then
+                    ngx.say("unexpected upstream node: ", res.body)
+                    return
+                end
+            end
+            ngx.say("pass")
+        }
+    }
+--- response_body
+pass
+--- grep_error_log eval
+qr/compare upstream nodes by value|fill node info for upstream|metadata_match/
+--- grep_error_log_out
+fill node info for upstream
+compare upstream nodes by value
+metadata_match found for upstream