fix(proxy-cache-advanced): the field age in response_headers has be…

…en changed from `age` to `Age` (#9360)

This PR fixed an issue where the field `age`  in response_headers has been changed from `age` to `Age`.
**Note:**
The value configured for age before the upgrade was not effective, and after the upgrade, the Age configuration will take effect. To maintain consistency in behavior before and after the upgrade, the "Age" needs to be set to false.

https://konghq.atlassian.net/browse/KM-198

changelog/unreleased/kong-ee/proxy_cache_advanced_Age.yml

@@ -0,0 +1,4 @@
+message: |
+  "**proxy-cache-advanced**: The configuration `Age` in response_headers  has been changed from lowercase to uppercase. Please reconfigure the `Age` if you need it."
+type: bugfix
+scope: Plugin

kong/clustering/compat/checkers.lua

@@ -38,6 +38,30 @@ end
 
 
 local compatible_checkers = {
+  { 3008000000, --[[ 3.8.0.0 ]]
+    function(config_table, dp_version, log_suffix)
+      local has_update
+      for _, plugin in ipairs(config_table.plugins or {}) do
+        if plugin.name == 'proxy-cache-advanced' then
+          local config = plugin.config
+          if config.response_headers["Age"] ~= nil then
+            config.response_headers.age = config.response_headers["Age"]
+            config.response_headers["Age"] = nil
+            has_update = true
+          end
+        end
+
+        if has_update then
+          log_warn_message(
+            'configures ' .. plugin.name .. ' plugin with:' ..
+            "the Age in response_headers",
+            "will be changed to age",
+            dp_version, log_suffix)
+        end
+      end
+      return has_update
+    end
+  },
   {
     3007001002, --[[3.7.1.2]]
     function(config_table, dp_version, log_suffix)

plugins-ee/proxy-cache-advanced/kong/plugins/proxy-cache-advanced/schema.lua

@@ -88,9 +88,9 @@ return {
             description = "Caching related diagnostic headers that should be included in cached responses",
             type = "record",
             fields = {
-              { age  = {type = "boolean",  default = true} },
-              { ["X-Cache-Status"]  = {type = "boolean",  default = true} },
-              { ["X-Cache-Key"]  = {type = "boolean",  default = true} },
+              { ["Age"] = { type = "boolean", default = true } },
+              { ["X-Cache-Status"] = { type = "boolean", default = true } },
+              { ["X-Cache-Key"] = { type = "boolean", default = true } },
             },
           }},
           { redis = redis.config_schema }, -- redis schema is provided by
@@ -100,6 +100,30 @@ return {
             default = false,
           }},
         },
+        shorthand_fields = {
+          {
+            response_headers = {
+              type = "json",
+              elements = { type = "boolean" },
+              deprecation = { message = "proxy-cache-advanced: config.response_headers.age has been changed from lowercase to uppercase, please use config.response_headers.Age instead", removal_in_version = "3.8", },
+              func = function(value)
+                local response_headers = {
+                  ["Age"] = value["Age"],
+                  ["X-Cache-Status"] = value["X-Cache-Status"],
+                  ["X-Cache-Key"] = value["X-Cache-Key"],
+                }
+
+                if value["age"] ~= nil then
+                  response_headers["Age"] = false
+                end
+
+                return {
+                  response_headers = response_headers,
+                }
+              end
+            }
+          },
+        }
       }
     },
   },

plugins-ee/proxy-cache-advanced/spec/02-access_spec.lua

@@ -160,6 +160,9 @@ for _, policy in ipairs({"memory", "redis"}) do
       local route22 = assert(bp.routes:insert {
         hosts = { "route-22.test" },
       })
+      local route23 = assert(bp.routes:insert {
+        hosts = { "route-23.test" },
+      })
 
       local consumer1 = assert(bp.consumers:insert {
         username = "bob",
@@ -392,6 +395,19 @@ for _, policy in ipairs({"memory", "redis"}) do
           },
         },
       })
+
+      assert(bp.plugins:insert {
+        name = "proxy-cache-advanced",
+        route = { id = route23.id },
+        config = {
+          strategy = policy,
+          content_type = { "text/plain", "application/json" },
+          [policy] = policy_config,
+          response_headers = {
+            age = true,
+          },
+        },
+      })
 
       assert(helpers.start_kong({
         plugins = "bundled,proxy-cache-advanced",
@@ -574,6 +590,7 @@ for _, policy in ipairs({"memory", "redis"}) do
 
       local body1 = assert.res_status(200, res)
       assert.same("Miss", res.headers["X-Cache-Status"])
+      assert.is_nil(res.headers["Age"])
 
       -- cache key is a sha256sum of the prefix uuid, method, and $request
       local cache_key1 = res.headers["X-Cache-Key"]
@@ -592,6 +609,7 @@ for _, policy in ipairs({"memory", "redis"}) do
 
       local body2 = assert.res_status(200, res)
       assert.same("Hit", res.headers["X-Cache-Status"])
+      assert.is_not_nil(res.headers["Age"])
       local cache_key2 = res.headers["X-Cache-Key"]
       assert.same(cache_key1, cache_key2)
 
@@ -629,6 +647,50 @@ for _, policy in ipairs({"memory", "redis"}) do
       assert.is_not_nil(res.headers["Age"])
       assert.is_not_nil(res.headers["X-Cache-Key"])
     end)
+
+    it("No Age headers on the response when enabling the response_headers.age", function()
+      local request = {
+        method = "GET",
+        path = "/get",
+        headers = {
+          host = "route-23.test",
+        },
+      }
+
+      local res = assert(client:send(request))
+      assert.res_status(200, res)
+      local res = assert(client:send(request))
+      assert.res_status(200, res)
+      assert.is_nil(res.headers["Age"])
+    end)
+
+    it("error log should have deprecated warning information for the response_headers.age", function()
+      local route24 = assert(bp.routes:insert({
+        hosts = { "route-24.test" },
+      }))
+      local request = {
+        method = "POST",
+        path = "/routes/" .. route24.id .. "/plugins",
+        headers = { ["Content-Type"] = "application/json", },
+        body = {
+          config = {
+            strategy = policy,
+            content_type = { "text/plain", "application/json" },
+            [policy] = policy_config,
+            response_headers = {
+              age = true,
+            }
+          },
+          name = "proxy-cache-advanced",
+        }
+      }
+
+      local res = assert(admin_client:send(request))
+      assert.res_status(201, res)
+      assert.logfile().has.line(
+        "proxy-cache-advanced: config.response_headers.age has been changed from lowercase to uppercase, please use config.response_headers.Age instead",
+        true, 1)
+    end)
 
     it("respects cache ttl", function()
       local res = assert(client:send {

spec-ee/02-integration/14-hybrid_mode/04-config-compat_spec.lua

@@ -814,6 +814,21 @@ describe("CP/DP config compat #" .. strategy, function()
             return config.redis.cluster_max_redirections == nil
           end
         },
+        {
+          plugin = "proxy-cache-advanced",
+          label = "w/ the field Age in response_headers has been changed from Age to age",
+          pending = false,
+          config = {
+            response_headers = {
+              Age = false,
+            },
+            strategy = "memory"
+          },
+          status = STATUS.NORMAL,
+          validator = function(config)
+            return config.response_headers.Age == nil and config.response_headers.age ~= nil
+          end
+        },
 
       }