Merge pull request #3341 from Shopify/canary_upstream

Add canary annotation and alternative backends for traffic shaping

rootfs/etc/nginx/lua/balancer/chash.lua

@@ -6,7 +6,10 @@ local _M = balancer_resty:new({ factory = resty_chash, name = "chash" })
 
 function _M.new(self, backend)
   local nodes = util.get_nodes(backend.endpoints)
-  local o = { instance = self.factory:new(nodes), hash_by = backend["upstream-hash-by"] }
+  local o = {
+    instance = self.factory:new(nodes),
+    hash_by = backend["upstream-hash-by"],
+  }
   setmetatable(o, self)
   self.__index = self
   return o

rootfs/etc/nginx/lua/balancer/ewma.lua

@@ -102,6 +102,9 @@ function _M.after_balance(_)
 end
 
 function _M.sync(self, backend)
+  self.traffic_shaping_policy = backend.trafficShapingPolicy
+  self.alternative_backends = backend.alternativeBackends
+
   local changed = not util.deep_compare(self.peers, backend.endpoints)
   if not changed then
     return
@@ -115,7 +118,9 @@ function _M.sync(self, backend)
 end
 
 function _M.new(self, backend)
-  local o = { peers = backend.endpoints }
+  local o = {
+    peers = backend.endpoints,
+  }
   setmetatable(o, self)
   self.__index = self
   return o

rootfs/etc/nginx/lua/balancer/resty.lua

@@ -10,6 +10,9 @@ function _M.new(self, o)
 end
 
 function _M.sync(self, backend)
+  self.traffic_shaping_policy = backend.trafficShapingPolicy
+  self.alternative_backends = backend.alternativeBackends
+
   local nodes = util.get_nodes(backend.endpoints)
   local changed = not util.deep_compare(self.instance.nodes, nodes)
   if not changed then

rootfs/etc/nginx/lua/balancer/round_robin.lua

@@ -6,7 +6,9 @@ local _M = balancer_resty:new({ factory = resty_roundrobin, name = "round_robin"
 
 function _M.new(self, backend)
   local nodes = util.get_nodes(backend.endpoints)
-  local o = { instance = self.factory:new(nodes) }
+  local o = {
+    instance = self.factory:new(nodes),
+  }
   setmetatable(o, self)
   self.__index = self
   return o