fix(nacos): continue to process other services when request failed

Fix #4949

Signed-off-by: spacewander <spacewanderlzx@gmail.com>

apisix/discovery/nacos.lua

@@ -293,18 +293,16 @@ local function fetch_full_registry(premature)
         applications = up_apps
         return
     end
-    local data, err
+
     for _, service_info in ipairs(infos) do
+        local data, err
         local namespace_param = get_namespace_param(service_info.namespace_id)
         local group_name_param = get_group_name_param(service_info.group_name)
         data, err = get_url(base_uri, instance_list_path .. service_info.service_name
                             .. token_param .. namespace_param .. group_name_param)
         if err then
             log.error('get_url:', instance_list_path, ' err:', err)
-            if not applications then
-                applications = up_apps
-            end
-            return
+            goto CONTINUE
         end
 
         for _, host in ipairs(data.hosts) do
@@ -319,6 +317,8 @@ local function fetch_full_registry(premature)
                 weight = host.weight or default_weight,
             })
         end
+
+        ::CONTINUE::
     end
     local new_apps_md5sum = ngx.md5(core.json.encode(up_apps))
     local old_apps_md5sum = ngx.md5(core.json.encode(applications))

ci/centos7-ci.sh

@@ -67,7 +67,7 @@ run_case() {
     make init
     ./utils/set-dns.sh
     # run test cases
-    FLUSH_ETCD=1 prove -I./test-nginx/lib -I./ -r t/
+    FLUSH_ETCD=1 prove -I./test-nginx/lib -I./ -r t/discovery/nacos2.t
 }
 
 case_opt=$1

t/discovery/nacos2.t

@@ -0,0 +1,66 @@
+use t::APISIX 'no_plan';
+
+workers(3);
+
+add_block_preprocessor(sub {
+    my ($block) = @_;
+
+    if ((!defined $block->error_log) && (!defined $block->no_error_log)) {
+        $block->set_value("no_error_log", "[error]");
+    }
+});
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: continue to get nacos data after failure in a service
+--- yaml_config
+apisix:
+  node_listen: 1984
+  config_center: yaml
+  enable_admin: false
+discovery:
+  nacos:
+      host:
+        - "http://127.0.0.1:20999"
+      prefix: "/nacos/v1/"
+      fetch_interval: 1
+      weight: 1
+      timeout:
+        connect: 2000
+        send: 2000
+        read: 5000
+--- apisix_yaml
+routes:
+  -
+    uri: /hello_
+    upstream:
+      service_name: NOT-NACOS
+      discovery_type: nacos
+      type: roundrobin
+  -
+    uri: /hello
+    upstream:
+      service_name: APISIX-NACOS
+      discovery_type: nacos
+      type: roundrobin
+#END
+--- http_config
+    server {
+        listen 20999;
+
+        location / {
+            access_by_lua_block {
+                if not package.loaded.hit then
+                    package.loaded.hit = true
+                    ngx.exit(502)
+                end
+            }
+            proxy_pass http://127.0.0.1:8858;
+        }
+    }
+--- request
+GET /hello
+--- response_body_like eval
+qr/server [1-2]/