Closing #1255

kong/cli/services/serf.lua

@@ -75,6 +75,12 @@ echo $COMMAND | ]]..luajit_path..[[
     return false, res
   end
 
+  -- Create the unique identifier if it doesn't exist
+  local _, err = cluster_utils.create_node_identifier(self._configuration)
+  if err then
+    return false, err
+  end
+
   return true
 end
 
@@ -112,7 +118,7 @@ function Serf:_autojoin(current_node_name)
       return false, tostring(err)
     else
       if #nodes == 0 then
-        logger:warn("Cannot auto-join the cluster because no nodes were found")
+        logger:info("No other Kong nodes were found in the cluster")
       else
         -- Sort by newest to oldest (although by TTL would be a better sort)
         table.sort(nodes, function(a, b)
@@ -144,7 +150,7 @@ function Serf:_add_node()
     return false, err
   end
 
-  local name = cluster_utils.get_node_name(self._configuration)
+  local name = cluster_utils.get_node_identifier(self._configuration)
   local addr
   for _, member in ipairs(members) do
     if member.name == name then
@@ -178,7 +184,7 @@ function Serf:start()
     return nil, err
   end
 
-  local node_name = cluster_utils.get_node_name(self._configuration)
+  local node_name = cluster_utils.get_node_identifier(self._configuration)
 
   -- Prepare arguments
   local cmd_args = {
@@ -269,7 +275,7 @@ function Serf:stop()
     -- Remove the node from the datastore.
     -- This is useful when this is the only node running in the cluster.
     self._dao_factory.nodes:delete({
-      name = cluster_utils.get_node_name(self._configuration)
+      name = cluster_utils.get_node_identifier(self._configuration)
     })
 
     -- Finally stop Serf

kong/core/cluster.lua

@@ -43,7 +43,7 @@ local function async_autojoin(premature)
         ngx.log(ngx.ERR, tostring(err))
       elseif #members < 2 then
         -- Trigger auto-join
-        local _, err = singletons.serf:_autojoin(cluster_utils.get_node_name(singletons.configuration))
+        local _, err = singletons.serf:_autojoin(cluster_utils.get_node_identifier(singletons.configuration))
         if err then
           ngx.log(ngx.ERR, tostring(err))
         end
@@ -73,7 +73,7 @@ local function send_keepalive(premature)
   local elapsed = lock:lock("keepalive")
   if elapsed and elapsed == 0 then
     -- Send keepalive
-    local node_name = cluster_utils.get_node_name(singletons.configuration)
+    local node_name = cluster_utils.get_node_identifier(singletons.configuration)
     local nodes, err = singletons.dao.nodes:find_all {name = node_name}
     if err then
       ngx.log(ngx.ERR, tostring(err))

kong/tools/cluster.lua

@@ -1,9 +1,30 @@
+local IO = require "kong.tools.io"
 local utils = require "kong.tools.utils"
+local singletons = require "kong.singletons"
 
 local _M = {}
 
-function _M.get_node_name(conf)
-  return utils.get_hostname().."_"..conf.cluster_listen
+local IDENTIFIER = "serf.id"
+
+function _M.get_node_identifier(conf)
+  local id = singletons.serf_id
+  if not id then
+    id = IO.read_file(IO.path:join(conf.nginx_working_dir, IDENTIFIER))
+    singletons.serf_id = id
+  end
+  return id
+end
+
+function _M.create_node_identifier(conf)
+  local path = IO.path:join(conf.nginx_working_dir, IDENTIFIER)
+  if not IO.file_exists(path) then
+    local id = utils.get_hostname().."_"..conf.cluster_listen.."_"..utils.random_string()
+    local _, err = IO.write_to_file(path, id)
+    if err then
+      return false, err
+    end
+  end
+  return true
 end
 
 return _M