fix: reevaluate logger meta filters during response phases

apisix/core/ctx.lua

@@ -208,6 +208,8 @@ do
         -- var.args should not be cached as it can be changed via set_uri_args
         args = true,
         is_args = true,
+        -- var.status changes after the response status is determined
+        status = true,
     }
 
     local ngx_var_names = {

apisix/plugin.lua

@@ -525,15 +525,16 @@ function _M.trace_expected_plugins_for_debug(api_ctx)
 end
 
 
-local function meta_filter(ctx, plugin_name, plugin_conf)
+local function meta_filter(ctx, plugin_name, plugin_conf, phase)
     local filter = plugin_conf._meta and plugin_conf._meta.filter
     if not filter then
         return true
     end
 
     local match_cache_key =
         ctx.conf_type .. "#" .. ctx.conf_id .. "#"
-            .. ctx.conf_version .. "#" .. plugin_name .. "#meta_filter_matched"
+            .. ctx.conf_version .. "#" .. plugin_name .. "#"
+            .. phase .. "#meta_filter_matched"
     if ctx[match_cache_key] ~= nil then
         return ctx[match_cache_key]
     end
@@ -1356,7 +1357,7 @@ function _M.run_plugin(phase, plugins, api_ctx)
             local phase_func = plugins[i][exec_phase]
             if phase_func then
                 local conf = plugins[i + 1]
-                if not meta_filter(api_ctx, plugins[i]["name"], conf)then
+                if not meta_filter(api_ctx, plugins[i]["name"], conf, phase) then
                     goto CONTINUE
                 end
 
@@ -1403,7 +1404,7 @@ function _M.run_plugin(phase, plugins, api_ctx)
     for i = 1, #plugins, 2 do
         local phase_func = plugins[i][phase]
         local conf = plugins[i + 1]
-        if phase_func and meta_filter(api_ctx, plugins[i]["name"], conf) then
+        if phase_func and meta_filter(api_ctx, plugins[i]["name"], conf, phase) then
             -- skip a plugin already run as a workflow action, before any meta hooks
             if api_ctx._skip_plugins and api_ctx._skip_plugins[plugins[i]["name"]] then
                 goto CONTINUE
@@ -1536,7 +1537,7 @@ function _M.lua_response_filter(api_ctx, headers, body, no_flush, wait)
             local phase_func = plugins[i]["lua_body_filter"]
             if phase_func then
                 local conf = plugins[i + 1]
-                if not meta_filter(api_ctx, plugins[i]["name"], conf)then
+                if not meta_filter(api_ctx, plugins[i]["name"], conf, "lua_body_filter") then
                     goto CONTINUE
                 end
 

t/core/ctx2.t

@@ -447,3 +447,26 @@ find ctx.var.a6_labels_zone: Singapore
 --- response_body
 find ctx.var.a6_count: 1
 find ctx.var.a6_count: 2
+
+
+
+=== TEST 20: status is not cached across response changes
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local ctx = {}
+            core.ctx.set_vars_meta(ctx)
+
+            ngx.status = 201
+            local first = ctx.var.status
+            ngx.status = 202
+            local second = ctx.var.status
+
+            ngx.status = 200
+            core.ctx.release_vars(ctx)
+            ngx.say(first, ", ", second)
+        }
+    }
+--- response_body
+201, 202

t/plugin/file-logger3.t

@@ -0,0 +1,186 @@
+#
+# 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';
+
+no_long_string();
+no_root_location();
+
+add_block_preprocessor(sub {
+    my ($block) = @_;
+
+    if (!$block->request) {
+        $block->set_value("request", "GET /t");
+    }
+
+    if (!$block->no_error_log && !$block->error_log) {
+        $block->set_value("no_error_log", "[error]\n[alert]");
+    }
+});
+
+run_tests;
+
+__DATA__
+
+=== TEST 1: configure response-phase filter
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            os.remove("file-logger-phase-filter.log")
+
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "file-logger": {
+                            "path": "file-logger-phase-filter.log",
+                            "log_format": {
+                                "status": "$status",
+                                "upstream_status": "$upstream_status"
+                            },
+                            "_meta": {
+                                "filter": [
+                                    ["upstream_status", "==", "201"]
+                                ]
+                            }
+                        }
+                    },
+                    "upstream": {
+                        "nodes": {
+                            "127.0.0.1:1980": 1
+                        },
+                        "type": "roundrobin"
+                    },
+                    "uri": "/*"
+                }]]
+            )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 2: reevaluate filter after upstream response
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local t = require("lib.test_admin").test
+            local code = t("/specific_status", ngx.HTTP_GET, nil, nil,
+                { ["x-test-upstream-status"] = "201" })
+
+            local file, err = io.open("file-logger-phase-filter.log", "r")
+            if not file then
+                core.log.error("failed to open log file: ", err)
+                ngx.status = 500
+                return
+            end
+
+            local entry = core.json.decode(file:read("*l"))
+            file:close()
+
+            ngx.status = code
+            ngx.say("status: ", entry.status)
+            ngx.say("upstream_status: ", entry.upstream_status)
+        }
+    }
+--- error_code: 201
+--- response_body
+status: 201
+upstream_status: 201
+
+
+
+=== TEST 3: configure a filtered logger and an unfiltered logger
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            os.remove("file-logger-status-cache.log")
+
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "http-logger": {
+                            "uri": "http://127.0.0.1:1980/log",
+                            "_meta": {
+                                "filter": [
+                                    ["status", "==", 404]
+                                ]
+                            }
+                        },
+                        "file-logger": {
+                            "path": "file-logger-status-cache.log",
+                            "log_format": {
+                                "status": "$status"
+                            }
+                        }
+                    },
+                    "upstream": {
+                        "nodes": {
+                            "127.0.0.1:1980": 1
+                        },
+                        "type": "roundrobin"
+                    },
+                    "uri": "/*"
+                }]]
+            )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 4: filtered logger does not cache status for another logger
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local t = require("lib.test_admin").test
+            local code = t("/specific_status", ngx.HTTP_GET, nil, nil,
+                { ["x-test-upstream-status"] = "201" })
+
+            local file, err = io.open("file-logger-status-cache.log", "r")
+            if not file then
+                core.log.error("failed to open log file: ", err)
+                ngx.status = 500
+                return
+            end
+
+            local entry = core.json.decode(file:read("*l"))
+            file:close()
+
+            ngx.status = code
+            ngx.say("status: ", entry.status)
+        }
+    }
+--- error_code: 201
+--- response_body
+status: 201