feat(sessions): store session's meatadata

kong-3.10.0-0.rockspec

@@ -555,10 +555,13 @@ build = {
     ["kong.plugins.session.header_filter"] = "kong/plugins/session/header_filter.lua",
     ["kong.plugins.session.session"] = "kong/plugins/session/session.lua",
     ["kong.plugins.session.daos"] = "kong/plugins/session/daos.lua",
+    ["kong.plugins.session.daos.session_metadatas"] = "kong/plugins/session/daos/session_metadatas.lua",
+    ["kong.plugins.session.strategies.postgres.session_metadatas"] = "kong/plugins/session/strategies/postgres/session_metadatas.lua",
     ["kong.plugins.session.storage.kong"] = "kong/plugins/session/storage/kong.lua",
     ["kong.plugins.session.migrations.000_base_session"] = "kong/plugins/session/migrations/000_base_session.lua",
     ["kong.plugins.session.migrations.001_add_ttl_index"] = "kong/plugins/session/migrations/001_add_ttl_index.lua",
     ["kong.plugins.session.migrations.002_320_to_330"] = "kong/plugins/session/migrations/002_320_to_330.lua",
+    ["kong.plugins.session.migrations.003_330_to_3100"] = "kong/plugins/session/migrations/003_330_to_3100.lua",
     ["kong.plugins.session.migrations"] = "kong/plugins/session/migrations/init.lua",
 
     ["kong.plugins.proxy-cache.handler"]              = "kong/plugins/proxy-cache/handler.lua",

kong/plugins/session/daos.lua

@@ -1,20 +1,39 @@
 local typedefs = require "kong.db.schema.typedefs"
 
 
-return {
-  {
-    primary_key = { "id" },
-    endpoint_key = "session_id",
-    name = "sessions",
-    cache_key = { "session_id" },
-    ttl = true,
-    db_export = false,
-    fields = {
-      { id = typedefs.uuid },
-      { session_id = { type = "string", unique = true, required = true } },
-      { expires = { type = "integer" } },
-      { data = { type = "string" } },
-      { created_at = typedefs.auto_timestamp_s },
-    }
+local sessions = {
+  primary_key = { "id" },
+  endpoint_key = "session_id",
+  name = "sessions",
+  cache_key = { "session_id" },
+  ttl = true,
+  db_export = false,
+  fields = {
+    { id = typedefs.uuid },
+    { session_id = { type = "string", unique = true, required = true } },
+    { expires = { type = "integer" } },
+    { data = { type = "string" } },
+    { created_at = typedefs.auto_timestamp_s },
+  }
+}
+
+local session_metadatas = {
+  primary_key = { "id" },
+  name = "session_metadatas",
+  dao  = "kong.plugins.session.daos.session_metadatas",
+  generate_admin_api = false,
+  db_export = false,
+  fields = {
+    { id = typedefs.uuid },
+    { session = { type = "foreign", reference = "sessions", required = true, on_delete = "cascade" } },
+    { sid = { type = "string" } },
+    { audience = { type = "string" } },
+    { subject = { type = "string" } },
+    { created_at = typedefs.auto_timestamp_s },
   }
 }
+
+return {
+  sessions,
+  session_metadatas,
+}

kong/plugins/session/daos/session_metadatas.lua

@@ -0,0 +1,18 @@
+local session_metadatas = {}
+
+function session_metadatas:select_by_audience_and_subject(audience, subject)
+  return self.strategy:select_by_audience_and_subject(audience, subject)
+end
+
+function session_metadatas:select_by_sid(sid)
+  local cache_key = kong.db.sessions:cache_key(sid)
+  local session = kong.cache:get(cache_key) or {}
+
+  local res = {}
+  for row in kong.db.session_metadatas:each_for_session({ id = session.id }) do
+    table.insert(res, row)
+  end
+  return res
+end
+
+return session_metadatas

kong/plugins/session/migrations/003_330_to_3100.lua

@@ -0,0 +1,22 @@
+return {
+  postgres = {
+    up = [[
+      CREATE TABLE IF NOT EXISTS session_metadatas(
+        id            uuid,
+        session_id    uuid                    REFERENCES "sessions" ("id") ON DELETE CASCADE,
+        sid           text UNIQUE,
+        subject       text,
+        audience      text,
+        created_at    timestamp WITH TIME ZONE,
+        PRIMARY KEY (id)
+      );
+
+      DO $$
+      BEGIN
+        CREATE INDEX IF NOT EXISTS "session_id_idx" ON "session_metadatas" ("session_id");
+      EXCEPTION WHEN UNDEFINED_COLUMN THEN
+        -- Do nothing, accept existing state
+      END$$;
+    ]],
+  },
+}

kong/plugins/session/migrations/init.lua

@@ -2,4 +2,5 @@ return {
   "000_base_session",
   "001_add_ttl_index",
   "002_320_to_330",
+  "003_330_to_3100",
 }

kong/plugins/session/schema.lua

@@ -212,6 +212,14 @@ return {
               default = "session_logout"
             }
           },
+          {
+            store_metadata = {
+              description =
+              "Whether to also store metadata of sessions, such as collecting data of sessions for a specific audience belonging to a specific subject.",
+              type = "boolean",
+              default = false
+            }
+          },
         },
         shorthand_fields = {
           -- TODO: deprecated forms, to be removed in Kong 4.0

kong/plugins/session/session.lua

@@ -43,6 +43,7 @@ function _M.open_session(conf)
     remember_absolute_timeout = conf.remember_absolute_timeout,
     response_headers          = conf.response_headers,
     request_headers           = conf.request_headers,
+    store_metadata            = conf.store_metadata or false,
   })
 end
 

kong/plugins/session/storage/kong.lua

@@ -38,15 +38,36 @@ local function load_session_from_cache(key)
   return kong.cache:get(cache_key, nil, load_session_from_db, key)
 end
 
+local function insert_session_metadata(metadata, session)
+  if not metadata then
+    return
+  end
 
-local function insert_session(key, value, ttl, current_time, old_key, stale_ttl, remember)
+  local audiences = metadata.audiences
+  local subjects  = metadata.subjects
+  local count     = #audiences
+  for i = 1, count do
+    kong.db.session_metadatas:insert({
+      sid      = session.session_id,
+      audience = audiences[i],
+      subject  = subjects[i],
+      session  = session,
+    })
+  end
+end
+
+local function insert_session(key, value, ttl, current_time, old_key, stale_ttl, metadata, remember)
   DATA.session_id = key
   DATA.data = value
   DATA.expires = current_time + ttl
 
   TTL.ttl = ttl
 
   local insert_ok, insert_err = kong.db.sessions:insert(DATA, TTL)
+  if not insert_err then
+    insert_session_metadata(metadata, insert_ok)
+  end
+
   if not old_key then
     return insert_ok, insert_err
   end
@@ -103,11 +124,11 @@ end
 
 function storage:set(name, key, value, ttl, current_time, old_key, stale_ttl, metadata, remember)
   if get_phase() == "header_filter" then
-    timer_at(0, insert_session_timer, key, value, ttl, current_time, old_key, stale_ttl, remember)
+    timer_at(0, insert_session_timer, key, value, ttl, current_time, old_key, stale_ttl, metadata, remember)
     return true
   end
 
-  return insert_session(key, value, ttl, current_time, old_key, stale_ttl, remember)
+  return insert_session(key, value, ttl, current_time, old_key, stale_ttl, metadata, remember)
 end
 
 

kong/plugins/session/strategies/postgres/session_metadatas.lua

@@ -0,0 +1,14 @@
+local fmt = string.format
+
+local session_metadatas = {}
+
+function session_metadatas:select_by_audience_and_subject(audience, subject)
+  local qs = fmt(
+    "SELECT * FROM session_metadatas WHERE audience = %s AND subject = %s;",
+    kong.db.connector:escape_literal(audience),
+    kong.db.connector:escape_literal(subject))
+
+  return kong.db.connector:query(qs, "read")
+end
+
+return session_metadatas

spec/05-migration/plugins/session/migrations/003_330_to_3100_spec.lua

@@ -0,0 +1,18 @@
+local uh = require "spec/upgrade_helpers"
+
+describe("database migration", function ()
+  if uh.database_type() == "postgres" then
+    uh.all_phases("has created the expected new columns", function()
+      assert.table_has_column("session_metadatas", "id", "uuid")
+      assert.table_has_column("session_metadatas", "session_id", "uuid")
+      assert.table_has_column("session_metadatas", "sid", "text")
+      assert.table_has_column("session_metadatas", "subject", "text")
+      assert.table_has_column("session_metadatas", "audience", "text")
+      assert.table_has_column("session_metadatas", "created_at", "timestamp with time zone", "timestamp")
+    end)
+
+    uh.all_phases("has created the expected indexes", function()
+      assert.table_has_index("session_metadatas", "session_id_idx")
+    end)
+  end
+end)