feat(conf_loader): load all WASM filters from conf path (#10353)

kong.conf.default

@@ -1904,3 +1904,8 @@
                                   # in a Kong cluster must have a unique and
                                   # valid UUID. When empty, node ID is
                                   # automatically generated.
+#wasm = off                       # Use this setting to enable WasmX, this allows running
+                                  # Wasm filters to process request data.
+
+#wasm_filters_path =              # Path to the directory containing Wasm filters
+                                  # that Kong must load on startup.

kong/conf_loader/init.lua

@@ -42,6 +42,7 @@ local concat = table.concat
 local getenv = os.getenv
 local exists = pl_path.exists
 local abspath = pl_path.abspath
+local isdir = pl_path.isdir
 local tostring = tostring
 local tonumber = tonumber
 local setmetatable = setmetatable
@@ -585,10 +586,9 @@ local CONF_PARSERS = {
   proxy_server = { typ = "string" },
   proxy_server_ssl_verify = { typ = "boolean" },
 
-  max_queued_batches = { typ = "number" },
-
   wasm = { typ = "boolean" },
-  wasm_modules = { typ = "array" },
+  wasm_filters_path = { typ = "string" },
+
   error_template_html = { typ = "string" },
   error_template_json = { typ = "string" },
   error_template_xml = { typ = "string" },
@@ -670,6 +670,18 @@ local function parse_value(value, typ)
 end
 
 
+-- Validate Wasm properties
+local function validate_wasm(wasm_enabled, filters_path)
+  if wasm_enabled and filters_path then
+    if not exists(filters_path) or not isdir(filters_path) then
+      return nil, fmt("wasm_filters_path '%s' is not a valid directory", filters_path)
+    end
+  end
+
+  return true
+end
+
+
 -- Validate properties (type/enum/custom) and infer their type.
 -- @param[type=table] conf The configuration table to treat.
 local function check_and_parse(conf, opts)
@@ -1297,6 +1309,14 @@ local function check_and_parse(conf, opts)
     end
   end
 
+  do
+    local ok, err = validate_wasm(conf.wasm, conf.wasm_filters_path)
+
+    if not ok then
+      errors[#errors + 1] = err
+    end
+  end
+
   return #errors == 0, errors[1], errors
 end
 
@@ -1478,6 +1498,34 @@ local function load_config_file(path)
   return load_config(f)
 end
 
+--- Get available Wasm filters list
+-- @param[type=string] Path where Wasm filters are stored.
+local function get_wasm_filters(filters_path)
+  local wasm_filters = {}
+
+  if filters_path then
+    local filter_files = {}
+    for entry in pl_path.dir(filters_path) do
+      local pathname = pl_path.join(filters_path, entry)
+      if not filter_files[pathname] and pl_path.isfile(pathname) then
+        filter_files[pathname] = pathname
+
+        local extension = pl_path.extension(entry)
+        if string.lower(extension) == ".wasm" then
+          insert(wasm_filters, {
+            name = entry:sub(0, -#extension - 1),
+            path = pathname,
+          })
+        else
+          log(DEBUG, "ignoring file ", entry, " in ", filters_path, ": does not contain wasm suffix")
+        end
+      end
+    end
+  end
+
+  return wasm_filters
+end
+
 
 --- Load Kong configuration
 -- The loaded configuration will have all properties from the default config
@@ -2038,25 +2086,9 @@ local function load(path, custom_conf, opts)
   assert(require("kong.tools.dns")(conf))
 
   -- WebAssembly module support
-  if conf.wasm_modules then
-    local paths = {}
-    local wasm_modules = {}
-
-    for _, pathname in ipairs(conf.wasm_modules) do
-      if not paths[pathname] then
-        paths[pathname] = path
-
-        local basename = pl_path.basename(pathname)
-        local extension = pl_path.extension(basename)
-
-        insert(wasm_modules, {
-          name = basename:sub(0, -#extension - 1),
-          path = pathname,
-        })
-      end
-    end
-
-    conf.wasm_modules_parsed = setmetatable(wasm_modules, _nop_tostring_mt)
+  if conf.wasm then
+    local wasm_filters = get_wasm_filters(conf.wasm_filters_path)
+    conf.wasm_modules_parsed = setmetatable(wasm_filters, _nop_tostring_mt)
   end
 
   return setmetatable(conf, nil) -- remove Map mt

kong/templates/kong_defaults.lua

@@ -205,8 +205,6 @@ opentelemetry_tracing_sampling_rate = 1.0
 tracing_instrumentations = off
 tracing_sampling_rate = 1.0
 
-max_queued_batches = 100
-
 wasm = off
-wasm_modules = NONE
+wasm_filters_path = NONE
 ]]

kong/templates/nginx.lua

@@ -19,12 +19,12 @@ events {
 > end
 }
 
-> if wasm then
+> if #wasm_modules_parsed > 0 then
 wasm {
   shm_kv kong_wasm_rate_limiting_counters 12m;
 
 > for _, module in ipairs(wasm_modules_parsed) do
-    module $(module.name) $(module.path);
+  module $(module.name) $(module.path);
 > end
 }
 

spec/01-unit/03-conf_loader_spec.lua

@@ -1693,19 +1693,47 @@ describe("Configuration loader", function()
   end)
 
   describe("#wasm properties", function()
-    it("wasm_modules", function()
+    it("wasm disabled", function()
       local conf, err = conf_loader(nil, {
-        wasm_modules = { "spec/fixtures/filter.wasm" },
+        wasm = "off",
+        wasm_filters_path = "spec/fixtures/wasm/unit-test",
+      })
+      assert.is_nil(err)
+      assert.is_nil(conf.wasm_modules_parsed)
+    end)
+
+    it("wasm default disabled", function()
+      local conf, err = conf_loader(nil, {
+        wasm_filters_path = "spec/fixtures/wasm/unit-test",
+      })
+      assert.is_nil(err)
+      assert.is_nil(conf.wasm_modules_parsed)
+    end)
+
+    it("wasm_filters_path", function()
+      local conf, err = conf_loader(nil, {
+        wasm = "on",
+        wasm_filters_path = "spec/fixtures/wasm/unit-test",
       })
       assert.is_nil(err)
       assert.same({
           {
-              name = "filter",
-              path = "spec/fixtures/filter.wasm",
+              name = "empty-filter",
+              path = "spec/fixtures/wasm/unit-test/empty-filter.wasm",
           }
       }, conf.wasm_modules_parsed)
-      assert.same({ "spec/fixtures/filter.wasm" }, conf.wasm_modules)
+      assert.same("spec/fixtures/wasm/unit-test", conf.wasm_filters_path)
+    end)
+
+    it("invalid wasm_filters_path", function()
+      local conf, err = conf_loader(nil, {
+        wasm = "on",
+        wasm_filters_path = "spec/fixtures/no-wasm-here/unit-test",
+      })
+      assert.same(err, "wasm_filters_path 'spec/fixtures/no-wasm-here/unit-test' is not a valid directory")
+      assert.is_nil(conf)
     end)
+
   end)
 
   describe("errors", function()

spec/01-unit/04-prefix_handler_spec.lua

@@ -773,13 +773,14 @@ describe("NGINX conf compiler", function()
     describe("#wasm subsystem", function()
       it("injects the wasm{} subsystem", function()
         local conf = assert(conf_loader(nil, {
-          wasm_modules = { "spec/fixtures/filter.wasm" },
+          wasm = "on",
+          wasm_filters_path = "spec/fixtures/wasm/unit-test/",
         }))
-        assert.is_true(conf.wasm)
+        assert.equal(conf.wasm_filters_path, "spec/fixtures/wasm/unit-test/")
 
         local nginx_conf = prefix_handler.compile_nginx_conf(conf)
         assert.matches("wasm {", nginx_conf)
-        assert.matches("module filter spec/fixtures/filter.wasm;", nginx_conf)
+        assert.matches("module empty%-filter spec/fixtures/wasm/unit%-test/empty%-filter.wasm;", nginx_conf)
       end)
     end)
   end)

spec/03-plugins/38-proxy-wasm/02-filters_spec.lua

@@ -68,7 +68,8 @@ describe("Plugin: proxy-wasm filters (#wasm)", function()
       database = DATABASE,
       plugins = "bundled, proxy-wasm",
       nginx_conf = "spec/fixtures/custom_nginx.template",
-      wasm_modules = PROXY_WASM_PATH .. "/target/wasm32-wasi/debug/tests.wasm",
+      wasm = "on",
+      wasm_filters_path = PROXY_WASM_PATH .. "/target/wasm32-wasi/debug",
     })
   end)
 

spec/fixtures/custom_nginx.template

@@ -20,13 +20,16 @@ events {
 > end
 }
 
-> if wasm then
+> if #wasm_modules_parsed > 0 then
 wasm {
+  shm_kv kong_wasm_rate_limiting_counters 12m;
+
 > for _, module in ipairs(wasm_modules_parsed) do
-    module $(module.name) $(module.path);
+  module $(module.name) $(module.path);
 > end
 }
 
+
 env RUST_BACKTRACE=1;
 env WASMTIME_BACKTRACE_DETAILS=1;
 > end