fix(declarative): generate correct uuid for transient entities (#14082)

Author: windmgc

changelog/unreleased/kong/fix-declarative-config-load.yml

@@ -0,0 +1,3 @@
+message: "Fixed an issue where a valid declarative config with certificate/sni entities cannot be loaded in dbless mode"
+type: bugfix
+scope: Core

kong/db/schema/others/declarative_config.lua

@@ -626,7 +626,7 @@ local function generate_ids(input, known_entities, parent_entity)
     local child_key
     if parent_entity then
       local parent_schema = all_schemas[parent_entity]
-      if parent_schema.fields[entity] then
+      if parent_schema.fields[entity] and not parent_schema.fields[entity].transient then
         goto continue
       end
       parent_fk = parent_schema:extract_pk_values(input)
@@ -663,7 +663,7 @@ local function populate_ids_for_validation(input, known_entities, parent_entity,
     local child_key
     if parent_entity then
       local parent_schema = all_schemas[parent_entity]
-      if parent_schema.fields[entity] then
+      if parent_schema.fields[entity] and not parent_schema.fields[entity].transient then
         goto continue
       end
       parent_fk = parent_schema:extract_pk_values(input)

spec/01-unit/01-db/10-declarative_spec.lua

@@ -1,6 +1,9 @@
 require("spec.helpers") -- for kong.log
 local declarative = require "kong.db.declarative"
 local conf_loader = require "kong.conf_loader"
+local uuid = require "kong.tools.uuid"
+
+local pl_file = require "pl.file"
 
 local null = ngx.null
 
@@ -64,4 +67,55 @@ keyauth_credentials:
     end)
   end)
 
+  it("parse nested entities correctly", function ()
+    -- This regression test case is to make sure that when a
+    -- "raw" input of declarative config is given, the dc parser
+    -- can generate correct UUIDs for those nested entites.
+    -- When the declarative config parser tries to flatten the
+    -- config input, the input will be running agains the
+    -- declarative_config schema validation. But some input
+    -- might lacks required fieds(such as UUIDS) and their
+    -- relationships are declared by nesting objects. In such
+    -- cases the declarative config parser must generate necessary
+    -- fields for all the objects(known entities) inside the config.
+    -- This test case is to make sure that the parser can generate
+    -- correct UUIDs for nested entities. What's more, it also makes
+    -- sure that UUID generation are not influenced by the `transient`
+    -- field(used as a backref to foreign objects) configured inside
+    -- the schema.
+    --
+    -- See https://github.com/Kong/kong/pull/14082 for more details.
+    local cluster_cert_content = assert(pl_file.read("spec/fixtures/kong_clustering.crt"))
+    local cluster_key_content = assert(pl_file.read("spec/fixtures/kong_clustering.key"))
+    local cert_id = uuid.uuid()
+    local sni_id = uuid.uuid()
+    local dc = declarative.new_config(conf_loader())
+    local entities, err = dc:parse_table(
+      {
+        _format_version = "3.0",
+        certificates = { {
+            cert = cluster_cert_content,
+            id = cert_id,
+            key = cluster_key_content,
+            snis = { {
+                id = sni_id,
+                name = "alpha.example"
+              } }
+          } },
+        consumers = { {
+            basicauth_credentials = { {
+                password = "qwerty",
+                username = "qwerty"
+              } },
+            username = "consumerA"
+          } }
+      }
+    )
+
+    assert.is_nil(err)
+    assert.is_table(entities)
+    assert.is_not_nil(entities.snis)
+    assert.same('alpha.example', entities.certificates[cert_id].snis[1].name)
+  end)
+
 end)