PR review refinements

kong/db/schema/entities/filter_chains.lua

@@ -1,7 +1,6 @@
 local typedefs = require "kong.db.schema.typedefs"
 local wasm = require "kong.runloop.wasm"
 
-local kong = kong
 
 ---@class kong.db.schema.entities.filter_chain : table
 ---
@@ -27,7 +26,8 @@ local kong = kong
 local filter = {
   type = "record",
   fields = {
-    { name    = { type = "string", required = true, one_of = wasm.filter_names, }, },
+    { name    = { type = "string", required = true, one_of = wasm.filter_names,
+                  err = "no such filter", }, },
     { config  = { type = "string", required = false, }, },
     { enabled = { type = "boolean", default = true, required = true, }, },
   },
@@ -73,35 +73,16 @@ return {
     -- validate filter chain input.
     --
     -- The `one_of` check on `filters[].name` already covers validation, but in
-    -- the case where wasm is disabled or no filters are installed, it will
-    -- return a cryptic error:
+    -- the case where wasm is disabled or no filters are installed, this check
+    -- adds an additional entity-level error (e.g. "wasm support is not enabled"
+    -- or "no wasm filters are available").
     --
-    -- ```
-    -- name = "expected one of: "
-    -- ```
-    --
-    -- This check simply adds an entity-level error message in those cases to
-    -- clarify.
+    -- All of the wasm API routes are disabled when wasm is also disabled, so
+    -- this primarily serves the dbless `/config` endpoint.
     { custom_entity_check = {
         field_sources = { "filters" },
         run_with_invalid_fields = true,
-        fn = function(_)
-          -- kong.runloop.wasm.enabled() doesn't differentiate between
-          -- wasm == "off" and #wasm_modules_parsed == 0, so we inspect
-          -- configuration here instead
-          if not wasm.enabled() then
-            if not kong.configuration.wasm then
-              return nil, "wasm is disabled"
-
-            elseif not kong.configuration.wasm_modules_parsed
-                   or #kong.configuration.wasm_modules_parsed == 0
-            then
-              return nil, "no wasm filters are available on this node"
-            end
-          end
-
-          return true
-        end,
+        fn = wasm.status,
       },
     },
   },

kong/runloop/wasm.lua

@@ -71,6 +71,8 @@ local TYPE_COMBINED = 2
 
 
 local ENABLED = false
+local STATUS = "wasm support is not enabled"
+
 
 local hash_chain
 do
@@ -536,47 +538,78 @@ local function get_filter_chain_for_request(route, service)
 end
 
 
+---@param filters kong.configuration.wasm_filter[]|nil
+local function set_available_filters(filters)
+  clear_tab(_M.filters)
+  clear_tab(_M.filters_by_name)
+  clear_tab(_M.filter_names)
+
+  if filters then
+    for i, filter in ipairs(filters) do
+      _M.filters[i] = filter
+      _M.filters_by_name[filter.name] = filter
+      _M.filter_names[i] = filter.name
+    end
+  end
+end
+
+
+---@param reason string
+local function disable(reason)
+  set_available_filters(nil)
+
+  _G.dns_client = nil
+
+  ENABLED = false
+  STATUS = reason or "wasm support is not enabled"
+end
+
+
+local function enable(kong_config)
+  set_available_filters(kong_config.wasm_modules_parsed)
+
+  -- setup a DNS client for ngx_wasm_module
+  _G.dns_client = _G.dns_client or dns(kong_config)
+
+  proxy_wasm = proxy_wasm or require "resty.wasmx.proxy_wasm"
+  ATTACH_OPTS.isolation = proxy_wasm.isolations.FILTER
+
+  ENABLED = true
+  STATUS = "wasm support is enabled"
+end
+
+
 _M.get_version = get_version
 
 _M.update_in_place = update_in_place
 
 _M.set_state = set_state
 
+function _M.enable(filters)
+  enable({
+    wasm = true,
+    wasm_modules_parsed = filters,
+  })
+end
+
+_M.disable = disable
+
 
 ---@param kong_config table
 function _M.init(kong_config)
-  -- we don't expect wasm.init() to be called more than once under normal
-  -- circumstances, but explicitly clearing these tables allows it to be
-  -- called multiple times in our tests
-  clear_tab(_M.filters)
-  clear_tab(_M.filters_by_name)
-  clear_tab(_M.filter_names)
+  if kong_config.wasm then
+    local filters = kong_config.wasm_modules_parsed
 
-  if not kong_config.wasm then
-    ENABLED = false
-    return
-  end
+    if filters and #filters > 0 then
+      enable(kong_config)
 
-  ---@type kong.configuration.wasm_filter[]
-  local modules = kong_config.wasm_modules_parsed
-  if not modules or #modules == 0 then
-    ENABLED = false
-    return
-  end
+    else
+      disable("no wasm filters are available")
+    end
 
-  for i, filter in ipairs(modules) do
-    _M.filters[i] = filter
-    _M.filters_by_name[filter.name] = filter
-    _M.filter_names[i] = filter.name
+  else
+    disable("wasm support is not enabled")
   end
-
-  -- setup a DNS client for ngx_wasm_module
-  _G.dns_client = dns(kong_config)
-
-  proxy_wasm = require "resty.wasmx.proxy_wasm"
-  ENABLED = true
-
-  ATTACH_OPTS.isolation = proxy_wasm.isolations.FILTER
 end
 
 
@@ -688,4 +721,14 @@ function _M.enabled()
 end
 
 
+---@return boolean? ok
+---@return string? error
+function _M.status()
+  if not ENABLED then
+    return nil, STATUS
+  end
+
+  return true
+end
+
 return _M

spec/02-integration/20-wasm/01-admin-api_spec.lua

@@ -21,12 +21,9 @@ describe("wasm admin API [#" .. strategy .. "]", function()
   local service, route
 
   lazy_setup(function()
-    require("kong.runloop.wasm").init({
-      wasm = true,
-      wasm_modules_parsed = {
-        { name = "tests" },
-        { name = "response_transformer" },
-      }
+    require("kong.runloop.wasm").enable({
+      { name = "tests" },
+      { name = "response_transformer" },
     })
 
     bp, db = helpers.get_db_utils(strategy, {

spec/02-integration/20-wasm/02-db_spec.lua

@@ -17,12 +17,9 @@ describe("wasm DB entities [#" .. strategy .. "]", function()
 
 
   lazy_setup(function()
-    require("kong.runloop.wasm").init({
-      wasm = true,
-      wasm_modules_parsed = {
-        { name = "test" },
-        { name = "other" },
-      }
+    require("kong.runloop.wasm").enable({
+      { name = "test" },
+      { name = "other" },
     })
 
     local _
@@ -317,8 +314,8 @@ describe("wasm DB entities [#" .. strategy .. "]", function()
           assert.is_table(err_t.fields)
           assert.same({
             filters = {
-              [2] = { name = "expected one of: test, other" },
-              [4] = { name = "expected one of: test, other" },
+              [2] = { name = "no such filter" },
+              [4] = { name = "no such filter" },
             },
           }, err_t.fields)
 
@@ -343,8 +340,8 @@ describe("wasm DB entities [#" .. strategy .. "]", function()
           assert.is_table(err_t.fields)
           assert.same({
             filters = {
-              [2] = { name = "expected one of: test, other" },
-              [4] = { name = "expected one of: test, other" },
+              [2] = { name = "no such filter" },
+              [4] = { name = "no such filter" },
             },
           }, err_t.fields)
 

spec/02-integration/20-wasm/03-runtime_spec.lua

@@ -24,12 +24,9 @@ for _, strategy in helpers.each_strategy({ "postgres", "off" }) do
 
 describe("#wasm filter execution (#" .. strategy .. ")", function()
   lazy_setup(function()
-    require("kong.runloop.wasm").init({
-      wasm = true,
-      wasm_modules_parsed = {
-        { name = "tests" },
-        { name = "response_transformer" },
-      },
+    require("kong.runloop.wasm").enable({
+      { name = "tests" },
+      { name = "response_transformer" },
     })
 
     local bp = helpers.get_db_utils("postgres", {

spec/02-integration/20-wasm/04-proxy-wasm_spec.lua

@@ -19,11 +19,8 @@ describe("proxy-wasm filters (#wasm)", function()
   local hosts_file
 
   lazy_setup(function()
-    require("kong.runloop.wasm").init({
-      wasm = true,
-      wasm_modules_parsed = {
-        { name = "tests" },
-      },
+    require("kong.runloop.wasm").enable({
+      { name = "tests" },
     })
 
     local bp, db = helpers.get_db_utils(DATABASE, {

spec/02-integration/20-wasm/05-cache-invalidation_spec.lua

@@ -196,12 +196,9 @@ describe("#wasm filter chain cache " .. mode_suffix, function()
 
 
   lazy_setup(function()
-    require("kong.runloop.wasm").init({
-      wasm = true,
-      wasm_modules_parsed = {
-        { name = "tests" },
-        { name = "response_transformer" },
-      },
+    require("kong.runloop.wasm").enable({
+      { name = "tests" },
+      { name = "response_transformer" },
     })
 
     local bp

spec/02-integration/20-wasm/07-declarative_spec.lua

@@ -49,7 +49,6 @@ end
 
 describe("#wasm declarative config", function()
   local client
-  local filter_names
 
   lazy_setup(function()
     assert(helpers.start_kong({
@@ -59,22 +58,6 @@ describe("#wasm declarative config", function()
     }))
 
     client = helpers.admin_client()
-
-    do
-      local res = client:get("/")
-      assert.response(res).has.status(200)
-      local json = assert.response(res).has.jsonbody()
-      assert.is_table(json.configuration)
-      assert.is_table(json.configuration.wasm_modules_parsed)
-      local filters = {}
-
-      for _, item in ipairs(json.configuration.wasm_modules_parsed) do
-        assert.is_table(item)
-        assert.is_string(item.name)
-        table.insert(filters, item.name)
-      end
-      filter_names = table.concat(filters, ", ")
-    end
   end)
 
   lazy_teardown(function()
@@ -114,8 +97,7 @@ describe("#wasm declarative config", function()
 
     assert.same("filters.1.name", err.field)
     assert.same("field", err.type)
-    assert.matches("expected one of: ", err.message)
-    assert.matches(filter_names, err.message)
+    assert.same("no such filter", err.message)
   end)
 end)
 
@@ -159,7 +141,7 @@ describe("#wasm declarative config (no installed filters)", function()
       },
     })
 
-    expect_entity_error(res, "no wasm filters are available on this node")
+    expect_entity_error(res, "no wasm filters are available")
   end)
 end)
 
@@ -197,6 +179,6 @@ describe("#wasm declarative config (wasm = off)", function()
       },
     })
 
-    expect_entity_error(res, "wasm is disabled")
+    expect_entity_error(res, "wasm support is not enabled")
   end)
 end)