feat: add control api for discovery module

apisix/control/router.lua

@@ -19,8 +19,10 @@ local router = require("apisix.utils.router")
 local builtin_v1_routes = require("apisix.control.v1")
 local plugin_mod = require("apisix.plugin")
 local core = require("apisix.core")
+
 local str_sub = string.sub
 local ipairs = ipairs
+local pairs = pairs
 local type = type
 local ngx = ngx
 local get_method = ngx.req.get_method
@@ -66,6 +68,38 @@ function fetch_control_api_router()
         end
     end
 
+    local discovery_type = require("apisix.core.config_local").local_conf().discovery
+    if discovery_type then
+        local discovery = require("apisix.discovery.init").discovery
+        local dump_apis = {}
+        for key, _ in pairs(discovery_type) do
+            local dis_mod = discovery[key]
+            -- if discovery module has control_api method, support it
+            local api_fun = dis_mod.control_api
+            if api_fun then
+                local api_route = api_fun()
+                register_api_routes(routes, api_route)
+            end
+
+            local dump_data = dis_mod.dump_data
+            if dump_data then
+                local item = {
+                    methods = {"GET"},
+                    uris = {"/v1/discovery/" .. key .. "/dump"},
+                    handler = function()
+                        return 200, dump_data()
+                    end
+                }
+                core.table.insert(dump_apis, item)
+            end
+        end
+
+        if #dump_apis > 0 then
+            core.log.notice("dump_apis: ", core.json.encode(dump_apis, true))
+            register_api_routes(routes, dump_apis)
+        end
+    end
+
     core.table.clear(v1_routes)
     register_api_routes(v1_routes, builtin_v1_routes)
 

apisix/discovery/consul_kv.lua

@@ -410,4 +410,5 @@ function _M.dump_data()
     return {config = local_conf.discovery.consul_kv, services = applications}
 end
 
+
 return _M

apisix/discovery/eureka.lua

@@ -252,4 +252,9 @@ function _M.init_worker()
 end
 
 
+function _M.dump_data()
+    return {config = local_conf.discovery.eureka, services = applications}
+end
+
+
 return _M

docs/en/latest/discovery.md

@@ -32,6 +32,7 @@ title: Integration service discovery registry
     * [**Initial service discovery**](#initial-service-discovery)
     * [**Configuration for Eureka**](#configuration-for-eureka)
 * [**Upstream setting**](#upstream-setting)
+* [**Embedded control api for debugging**](#embedded-control-api-for-debugging)
 * [**Discovery modules**](#discovery-modules)
 
 ## Summary
@@ -66,7 +67,9 @@ It is very easy for APISIX to extend the discovery client, the basic steps are a
 
 2. Implement the `_M. init_worker()` function for initialization and the `_M. nodes(service_name)` function for obtaining the list of service instance nodes;
 
-3. Convert the registry data into data in APISIX;
+3. If you need the discovery module to export the debugging information online,  implement the `_M. dump_data()` function;
+
+4. Convert the registry data into data in APISIX;
 
 ### the example of Eureka
 
@@ -92,6 +95,11 @@ Then implement the `_M.init_worker()` function for initialization and the `_M.no
   end
 
 
+  function _M.dump_data()
+      ... ...
+  end
+
+
   return _M
   ```
 
@@ -256,3 +264,30 @@ $ curl http://127.0.0.1:9080/apisix/admin/routes/2 -H 'X-API-KEY: edd1c9f034335f
 Suppose both A-SERVICE and B-SERVICE provide a `/test` API. The above configuration allows access to A-SERVICE's `/test` API through `/a/test` and B-SERVICE's `/test` API through `/b/test`.
 
 **Notice**：When configuring `upstream.service_name`,  `upstream.nodes` will no longer take effect, but will be replaced by 'nodes' obtained from the registry.
+
+## Embedded control api for debugging
+
+Sometimes we need the discovery client to export online data snapshot in memory when running for debugging, and if you implement the `_M. dump_data()` function:
+
+```lua
+function _M.dump_data()
+    return {config = local_conf.discovery.eureka, services = applications}
+end
+```
+
+Then you can call its control api as below:
+
+```shell
+GET /v1/discovery/{discovery_type}/dump
+```
+
+eg:
+
+```shell
+curl http://127.0.0.1:9090/v1/discovery/eureka/dump
+```
+
+## Discovery modules
+
+- eureka
+- [Consul KV](discovery/consul_kv.md)

docs/en/latest/discovery/consul_kv.md

@@ -147,4 +147,77 @@ You could find more usage in the `apisix/t/discovery/consul_kv.t` file.
 
 ## Debugging API
 
-TODO
+It also offers control api for debugging:
+
+```shell
+GET /v1/discovery/consul_kv/dump
+```
+
+For example:
+
+```shell
+# curl http://127.0.0.1:9090/v1/discovery/consul_kv/dump | jq
+{
+  "config": {
+    "fetch_interval": 3,
+    "timeout": {
+      "wait": 60,
+      "connect": 6000,
+      "read": 6000
+    },
+    "prefix": "upstreams",
+    "weight": 1,
+    "servers": [
+      "http://172.19.5.30:8500",
+      "http://172.19.5.31:8500"
+    ],
+    "keepalive": true,
+    "default_service": {
+      "host": "172.19.5.11",
+      "port": 8899,
+      "metadata": {
+        "fail_timeout": 1,
+        "weigth": 1,
+        "weight": 1,
+        "max_fails": 1
+      }
+    },
+    "skip_keys": [
+      "upstreams/myapi/gateway/apisix/"
+    ]
+  },
+  "services": {
+    "http://172.19.5.31:8500/v1/kv/upstreams/webpages/": [
+      {
+        "host": "127.0.0.1",
+        "port": 30513,
+        "weight": 1
+      },
+      {
+        "host": "127.0.0.1",
+        "port": 30514,
+        "weight": 1
+      }
+    ],
+    "http://172.19.5.30:8500/v1/kv/upstreams/1614480/grpc/": [
+      {
+        "host": "172.19.5.51",
+        "port": 50051,
+        "weight": 1
+      }
+    ],
+    "http://172.19.5.30:8500/v1/kv/upstreams/webpages/": [
+      {
+        "host": "127.0.0.1",
+        "port": 30511,
+        "weight": 1
+      },
+      {
+        "host": "127.0.0.1",
+        "port": 30512,
+        "weight": 1
+      }
+    ]
+  }
+}
+```

t/control/discovery.t

@@ -0,0 +1,102 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+use t::APISIX 'no_plan';
+
+repeat_each(1);
+no_long_string();
+no_root_location();
+no_shuffle();
+log_level("info");
+
+
+our $yaml_config = <<_EOC_;
+apisix:
+  enable_control: true
+  node_listen: 1984
+  config_center: yaml
+  enable_admin: false
+
+discovery:
+  eureka:
+    host:
+      - "http://127.0.0.1:8761"
+    prefix: "/eureka/"
+    fetch_interval: 10
+    weight: 80
+    timeout:
+      connect: 1500
+      send: 1500
+      read: 1500
+  consul_kv:
+    servers:
+      - "http://127.0.0.1:8500"
+      - "http://127.0.0.1:8600"
+  dns:
+    servers:
+      - "127.0.0.1:1053"
+_EOC_
+
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: test consul_kv dump_data api
+--- yaml_config eval: $::yaml_config
+--- request
+GET /v1/discovery/consul_kv/dump
+--- error_code: 200
+--- response_body_unlike
+^{}$
+
+
+
+=== TEST 2: test eureka dump_data api
+--- yaml_config eval: $::yaml_config
+--- request
+GET /v1/discovery/eureka/dump
+--- error_code: 200
+--- response_body_unlike
+^{}$
+
+
+
+=== TEST 3: test dns api
+--- yaml_config eval: $::yaml_config
+--- request
+GET /v1/discovery/dns/dump
+--- error_code: 404
+
+
+
+=== TEST 4: test unconfiged consul_kv dump_data api
+--- yaml_config
+apisix:
+  enable_control: true
+  node_listen: 1984
+  config_center: yaml
+  enable_admin: false
+
+discovery:
+  consul_kv:
+    servers:
+      - "http://127.0.0.1:8500"
+      - "http://127.0.0.1:8600"
+#END
+--- request
+GET /v1/discovery/eureka/dump
+--- error_code: 404

t/discovery/consul_kv.t

@@ -113,7 +113,7 @@ run_tests();
 
 __DATA__
 
-=== TEST 1: clean consul kv register nodes
+=== TEST 1: prepare consul kv register nodes
 --- config
 location /consul1 {
     rewrite  ^/consul1/(.*) /v1/kv/$1 break;
@@ -289,7 +289,7 @@ GET /hello
 
 
 
-=== TEST 7: test register&register nodes
+=== TEST 7: test register and unregister nodes
 --- yaml_config eval: $::yaml_config
 --- apisix_yaml
 routes: