fix(proxy-cache): provide error instead of nil panic when cache_zone …

…is missing (#10138)

apisix/plugins/proxy-cache/init.lua

@@ -25,6 +25,7 @@ local plugin_name = "proxy-cache"
 
 local STRATEGY_DISK = "disk"
 local STRATEGY_MEMORY = "memory"
+local DEFAULT_CACHE_ZONE = "disk_cache_one"
 
 local schema = {
     type = "object",
@@ -33,7 +34,7 @@ local schema = {
             type = "string",
             minLength = 1,
             maxLength = 100,
-            default = "disk_cache_one",
+            default = DEFAULT_CACHE_ZONE,
         },
         cache_strategy = {
             type = "string",
@@ -129,14 +130,23 @@ function _M.check_schema(conf)
     local found = false
     local local_conf = core.config.local_conf()
     if local_conf.apisix.proxy_cache then
+        local err = "cache_zone " .. conf.cache_zone .. " not found"
         for _, cache in ipairs(local_conf.apisix.proxy_cache.zones) do
+            -- cache_zone passed in plugin config matched one of the proxy_cache zones
             if cache.name == conf.cache_zone then
-                found = true
+                -- check for the mismatch between cache_strategy and corresponding cache zone
+                if (conf.cache_strategy == STRATEGY_MEMORY and cache.disk_path) or
+                (conf.cache_strategy == STRATEGY_DISK and not cache.disk_path) then
+                    err =  "invalid or empty cache_zone for cache_strategy: "..conf.cache_strategy
+                else
+                    found = true
+                end
+                break
             end
         end
 
         if found == false then
-            return false, "cache_zone " .. conf.cache_zone .. " not found"
+            return false, err
         end
     end
 

apisix/plugins/proxy-cache/memory.lua

@@ -32,6 +32,10 @@ end
 
 
 function _M:set(key, obj, ttl)
+    if self.dict == nil then
+        return nil, "invalid cache_zone provided"
+    end
+
     local obj_json = core.json.encode(obj)
     if not obj_json then
         return nil, "could not encode object"
@@ -43,6 +47,10 @@ end
 
 
 function _M:get(key)
+    if self.dict == nil then
+        return nil, "invalid cache_zone provided"
+    end
+
     -- If the key does not exist or has expired, then res_json will be nil.
     local res_json, err = self.dict:get(key)
     if not res_json then
@@ -63,6 +71,9 @@ end
 
 
 function _M:purge(key)
+    if self.dict == nil then
+        return nil, "invalid cache_zone provided"
+    end
     self.dict:delete(key)
 end
 

t/plugin/proxy-cache/memory.t

@@ -661,3 +661,46 @@ GET /hello
 --- more_headers
 Cache-Control: only-if-cached
 --- error_code: 504
+
+
+
+=== TEST 36: configure plugin without memory_cache zone for cache_strategy = memory
+--- config
+       location /t {
+           content_by_lua_block {
+               local t = require("lib.test_admin").test
+               local code, body = t('/apisix/admin/routes/1',
+                    ngx.HTTP_PUT,
+                    [[{
+                        "plugins": {
+                            "proxy-cache": {
+                               "cache_strategy": "memory",
+                               "cache_key":["$host","$uri"],
+                               "cache_bypass": ["$arg_bypass"],
+                               "cache_control": true,
+                               "cache_method": ["GET"],
+                               "cache_ttl": 10,
+                               "cache_http_status": [200]
+                            }
+                        },
+                        "upstream": {
+                            "nodes": {
+                                "127.0.0.1:1986": 1
+                            },
+                            "type": "roundrobin"
+                        },
+                        "uri": "/hello"
+                   }]]
+                   )
+
+               if code >= 300 then
+                   ngx.status = code
+               end
+               ngx.say(body)
+           }
+       }
+--- request
+GET /t
+--- response_body_like
+.*err: invalid or empty cache_zone for cache_strategy: memory.*
+--- error_code: 400