fix(admin) proper support for `PUT /{entities}/{entity}/plugins/{plug…

…in}`

Prior to this patch, `PUT` requests to plugins under their associated
resources (e.g. `/services/{service}/plugins/{plugin}`) would
systematically return `404`, instead of creating the plugin if it did
not exist. This was because the `before` Lapis hook attempts to retrieve
the plugin in the database before modifying it. Those endpoints are
preserved for backwards-compatibility purposes (being too nested to be
auto-generated), so that workaround is fine.

This patch ensures that we skip this logic with `PUT` requests, plus
makes sure that we set the `self.args.post` arguments according to the
`self.params` arguments (path segments with foreign UUIDs).

Thanks @gszr for the report.

From #4288

kong/api/routes/plugins.lua

@@ -13,12 +13,15 @@ local setmetatable = setmetatable
 
 
 local get_plugin = endpoints.get_entity_endpoint(kong.db.plugins.schema)
-local put_plugin = endpoints.put_entity_endpoint(kong.db.plugins.schema)
 local delete_plugin = endpoints.delete_entity_endpoint(kong.db.plugins.schema)
 
 
 local function before_plugin_for_entity(entity_name, plugin_field)
   return function(self, db, helpers)
+    if kong.request.get_method() == "PUT" then
+      return
+    end
+
     local entity, _, err_t = endpoints.select_entity(self, db, kong.db[entity_name].schema)
     if err_t then
       return endpoints.handle_error(err_t)
@@ -44,8 +47,10 @@ local function before_plugin_for_entity(entity_name, plugin_field)
 end
 
 
-local function fill_plugin_data(args, plugin)
-  local post = args.post
+local function fill_plugin_data(self, plugin)
+  plugin = plugin or {}
+
+  local post = self.args.post
 
   post.name = post.name or plugin.name
 
@@ -57,19 +62,40 @@ local function fill_plugin_data(args, plugin)
   post.service = post.service or plugin.service
   post.consumer = post.consumer or plugin.consumer
 
-  args.post = post
+  if not post.route and self.params.routes then
+    post.route = { id = self.params.routes }
+  end
+
+  if not post.service and self.params.services then
+    post.service = { id = self.params.services }
+  end
+
+  if not post.consumer and self.params.consumers then
+    post.consumer = { id = self.params.consumers }
+  end
+
+  self.args.post = post
 end
 
 
 local patch_plugin
+local put_plugin
 do
-  local patch_plugin_endpoint = endpoints.patch_entity_endpoint(kong.db.plugins.schema)
+  local schema = kong.db.plugins.schema
+
+  local patch_plugin_endpoint = endpoints.patch_entity_endpoint(schema)
+  local put_plugin_endpoint = endpoints.put_entity_endpoint(schema)
 
   patch_plugin = function(self, db, helpers)
     local plugin = self.plugin
-    fill_plugin_data(self.args, plugin)
+    fill_plugin_data(self, plugin)
     return patch_plugin_endpoint(self, db, helpers)
   end
+
+  put_plugin = function(self, db, helpers)
+    fill_plugin_data(self)
+    return put_plugin_endpoint(self, db, helpers)
+  end
 end
 
 
@@ -206,7 +232,7 @@ return {
           return kong.response.exit(404, { message = "Not found" })
         end
 
-        fill_plugin_data(self.args, plugin)
+        fill_plugin_data(self, plugin)
       end
       return parent()
     end,

spec/02-integration/04-admin_api/03-consumers_routes_spec.lua

@@ -899,6 +899,65 @@ describe("Admin API (#" .. strategy .. "): ", function()
       end)
     end)
 
+    describe("PUT", function()
+      local inputs = {
+        ["application/x-www-form-urlencoded"] = {
+          name = "rewriter",
+          ["config.value"] = "updated",
+        },
+        ["application/json"] = {
+          name = "rewriter",
+          config = {
+            value = "updated",
+          }
+        }
+      }
+
+      for content_type, input in pairs(inputs) do
+        it("creates if not found with " .. content_type, function()
+          local consumer = bp.consumers:insert()
+          local plugin_id = utils.uuid()
+
+          local res = assert(client:send {
+            method = "PUT",
+            path = "/consumers/" .. consumer.id .. "/plugins/" .. plugin_id,
+            body = input,
+            headers = { ["Content-Type"] = content_type },
+          })
+          local body = assert.res_status(200, res)
+          local json = cjson.decode(body)
+          assert.equal("updated", json.config.value)
+          assert.equal(plugin_id, json.id)
+
+          local in_db = assert(db.plugins:select({
+            id = plugin_id,
+          }, { nulls = true }))
+          assert.same(json, in_db)
+        end)
+
+        it("updates if found with " .. content_type, function()
+          local consumer = bp.consumers:insert()
+          local plugin = bp.rewriter_plugins:insert({ consumer = { id = consumer.id }})
+
+          local res = assert(client:send {
+            method = "PUT",
+            path = "/consumers/" .. consumer.id .. "/plugins/" .. plugin.id,
+            body = input,
+            headers = { ["Content-Type"] = content_type },
+          })
+          local body = assert.res_status(200, res)
+          local json = cjson.decode(body)
+          assert.equal("updated", json.config.value)
+          assert.equal(plugin.id, json.id)
+
+          local in_db = assert(db.plugins:select({
+            id = plugin.id,
+          }, { nulls = true }))
+          assert.same(json, in_db)
+        end)
+      end
+    end)
+
     describe("DELETE", function()
       it("deletes a plugin configuration", function()
         local consumer = bp.consumers:insert()