Merge pull request #3740 from Shopify/session-annotation-reload

Fix ingress updating for session-cookie-* annotation changes

rootfs/etc/nginx/lua/balancer/sticky.lua

@@ -4,24 +4,30 @@ local util = require("util")
 local ck = require("resty.cookie")
 
 local _M = balancer_resty:new({ factory = resty_chash, name = "sticky" })
+local DEFAULT_COOKIE_NAME = "route"
+
+local function get_digest_func(hash)
+  local digest_func = util.md5_digest
+  if hash == "sha1" then
+    digest_func = util.sha1_digest
+  end
+  return digest_func
+end
+
+function _M.cookie_name(self)
+  return self.cookie_session_affinity.name or DEFAULT_COOKIE_NAME
+end
 
 function _M.new(self, backend)
   local nodes = util.get_nodes(backend.endpoints)
-  local digest_func = util.md5_digest
-  if backend["sessionAffinityConfig"]["cookieSessionAffinity"]["hash"] == "sha1" then
-    digest_func = util.sha1_digest
-  end
+  local digest_func = get_digest_func(backend["sessionAffinityConfig"]["cookieSessionAffinity"]["hash"])
 
   local o = {
     instance = self.factory:new(nodes),
-    cookie_name = backend["sessionAffinityConfig"]["cookieSessionAffinity"]["name"] or "route",
-    cookie_expires = backend["sessionAffinityConfig"]["cookieSessionAffinity"]["expires"],
-    cookie_max_age = backend["sessionAffinityConfig"]["cookieSessionAffinity"]["maxage"],
-    cookie_path = backend["sessionAffinityConfig"]["cookieSessionAffinity"]["path"],
-    cookie_locations = backend["sessionAffinityConfig"]["cookieSessionAffinity"]["locations"],
     digest_func = digest_func,
     traffic_shaping_policy = backend.trafficShapingPolicy,
     alternative_backends = backend.alternativeBackends,
+    cookie_session_affinity = backend["sessionAffinityConfig"]["cookieSessionAffinity"]
   }
   setmetatable(o, self)
   self.__index = self
@@ -43,25 +49,25 @@ local function set_cookie(self, value)
     ngx.log(ngx.ERR, err)
   end
 
-  local cookie_path = self.cookie_path
+  local cookie_path = self.cookie_session_affinity.path
   if not cookie_path then
     cookie_path = ngx.var.location_path
   end
 
   local cookie_data = {
-    key = self.cookie_name,
+    key = self:cookie_name(),
     value = value,
     path = cookie_path,
     httponly = true,
     secure = ngx.var.https == "on",
   }
 
-  if self.cookie_expires and self.cookie_expires ~= "" then
-      cookie_data.expires = ngx.cookie_time(ngx.time() + tonumber(self.cookie_expires))
+  if self.cookie_session_affinity.expires and self.cookie_session_affinity.expires ~= "" then
+      cookie_data.expires = ngx.cookie_time(ngx.time() + tonumber(self.cookie_session_affinity.expires))
   end
 
-  if self.cookie_max_age and self.cookie_max_age ~= "" then
-    cookie_data.max_age = tonumber(self.cookie_max_age)
+  if self.cookie_session_affinity.maxage and self.cookie_session_affinity.maxage ~= "" then
+    cookie_data.max_age = tonumber(self.cookie_session_affinity.maxage)
   end
 
   local ok
@@ -78,13 +84,13 @@ function _M.balance(self)
     return
   end
 
-  local key = cookie:get(self.cookie_name)
+  local key = cookie:get(self:cookie_name())
   if not key then
     local random_str = string.format("%s.%s", ngx.now(), ngx.worker.pid())
     key = encrypted_endpoint_string(self, random_str)
 
-    if self.cookie_locations then
-      local locs = self.cookie_locations[ngx.var.host]
+    if self.cookie_session_affinity.locations then
+      local locs = self.cookie_session_affinity.locations[ngx.var.host]
       if locs ~= nil then
         for _, path in pairs(locs) do
           if ngx.var.location_path == path then
@@ -99,4 +105,20 @@ function _M.balance(self)
   return self.instance:find(key)
 end
 
+function _M.sync(self, backend)
+  balancer_resty.sync(self, backend)
+
+  -- Reload the balancer if any of the annotations have changed.
+  local changed = not util.deep_compare(
+    self.cookie_session_affinity,
+    backend.sessionAffinityConfig.cookieSessionAffinity
+  )
+  if not changed then
+    return
+  end
+
+  self.cookie_session_affinity = backend.sessionAffinityConfig.cookieSessionAffinity
+  self.digest_func = get_digest_func(backend.sessionAffinityConfig.cookieSessionAffinity.hash)
+end
+
 return _M

rootfs/etc/nginx/lua/test/balancer/sticky_test.lua

@@ -55,7 +55,7 @@ describe("Sticky", function()
       it("returns an instance containing the corresponding cookie name", function()
         local sticky_balancer_instance = sticky:new(test_backend)
         local test_backend_cookie_name = test_backend.sessionAffinityConfig.cookieSessionAffinity.name
-        assert.equal(sticky_balancer_instance.cookie_name, test_backend_cookie_name)
+        assert.equal(sticky_balancer_instance:cookie_name(), test_backend_cookie_name)
       end)
     end)
 
@@ -65,7 +65,7 @@ describe("Sticky", function()
         temp_backend.sessionAffinityConfig.cookieSessionAffinity.name = nil
         local sticky_balancer_instance = sticky:new(temp_backend)
         local default_cookie_name = "route"
-        assert.equal(sticky_balancer_instance.cookie_name, default_cookie_name)
+        assert.equal(sticky_balancer_instance:cookie_name(), default_cookie_name)
       end)
     end)