fix(proxy-rewrite): when conf.headers are missing,conf.method can mak…

…e effect (#6300)

Co-authored-by: 高亮亮 <gll287546@alibaba-inc.com>

apisix/plugins/proxy-rewrite.lua

@@ -195,22 +195,20 @@ function _M.rewrite(conf, ctx)
         ctx.var.upstream_uri = upstream_uri
     end
 
-    if not conf.headers then
-        return
-    end
-
-    if not conf.headers_arr then
-        conf.headers_arr = {}
+    if conf.headers then
+        if not conf.headers_arr then
+            conf.headers_arr = {}
 
-        for field, value in pairs(conf.headers) do
-            core.table.insert_tail(conf.headers_arr, field, value)
+            for field, value in pairs(conf.headers) do
+                core.table.insert_tail(conf.headers_arr, field, value)
+            end
         end
-    end
 
-    local field_cnt = #conf.headers_arr
-    for i = 1, field_cnt, 2 do
-        core.request.set_header(ctx, conf.headers_arr[i],
-                                core.utils.resolve_var(conf.headers_arr[i+1], ctx.var))
+        local field_cnt = #conf.headers_arr
+        for i = 1, field_cnt, 2 do
+            core.request.set_header(ctx, conf.headers_arr[i],
+                                    core.utils.resolve_var(conf.headers_arr[i+1], ctx.var))
+        end
     end
 
     if conf.method then

t/plugin/proxy-rewrite3.t

@@ -79,7 +79,7 @@ passed
 === TEST 2: hit route(upstream uri: should be /hello)
 --- request
 GET /hello
---- grep_error_log_out
+--- error_log
 plugin_proxy_rewrite get method: POST
 
 
@@ -125,7 +125,7 @@ passed
 === TEST 4: hit route(upstream uri: should be /hello)
 --- request
 GET /hello
---- grep_error_log_out
+--- error_log
 plugin_proxy_rewrite get method: GET
 
 
@@ -151,3 +151,52 @@ plugin_proxy_rewrite get method: GET
 --- response_body
 property "method" validation failed: matches none of the enum values
 done
+
+
+
+=== TEST 6: set route(rewrite method with headers)
+--- 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,
+                 [[{
+                        "methods": ["GET"],
+                        "plugins": {
+                            "proxy-rewrite": {
+                                "uri": "/plugin_proxy_rewrite",
+                                "method": "POST",
+                                "scheme": "http",
+                                "host": "apisix.iresty.com",
+                                "headers":{
+                                    "x-api-version":"v1"
+                                }
+                            }
+                        },
+                        "upstream": {
+                            "nodes": {
+                                "127.0.0.1:1980": 1
+                            },
+                            "type": "roundrobin"
+                        },
+                        "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 7: hit route(with header)
+--- request
+GET /hello
+--- error_log
+plugin_proxy_rewrite get method: POST