lua-resty-upstream-etcd
!!!This module is under heavy development, do not use in production environment.!!!
A lua module for OpenResty, can dynamically update the upstreams from etcd.
DEPENDENCE
- openresty-1.9.7.3 + (balancer_by_lua*)
- lua-resty-http
- cjson
USAGE
Prepare data in etcd:
etcdctl set /v1/testing/services/my_test_service/10.1.1.1:8080 '{"weight": 3}'
etcdctl set /v1/testing/services/my_test_service/10.1.1.2:8080 '{"weight": 4}'
etcdctl set /v1/testing/services/my_test_service/10.1.1.3:8080 '{"weight": 5}'
Value should be a json, now round_robin_with_weight() support the weight for load balancing, works like nginx round-robin.
The default weight is 1, if not set in ETCD, or json parse error and so on.
Init the module:
lua_socket_log_errors off; # recommend
lua_shared_dict dyups 10k; # for global lock and version
init_worker_by_lua_block {
local u = require "dyups"
u.init({
etcd_host = "127.0.0.1",
etcd_port = 2379,
etcd_path = "/v1/testing/services/",
-- The real path of the dump file will be: /tmp/nginx-upstreams_v1_testing_services_
dump_file = "/tmp/nginx-upstreams",
-- Slow-start in N seconds from 0 to configured weight for the newly added peer
slow_start = 10,
dict = ngx.shared.dyups
})
}
Get a server in upstream:
upstream test {
server 127.0.0.1:2222; # fake server
balancer_by_lua_block {
local balancer = require "ngx.balancer"
local u = require "dyups"
local s, err = u.round_robin_server("my_test_service")
if not s then
ngx.log(ngx.ERR, err)
return ngx.exit(500)
end
local ok, err = balancer.set_current_peer(s.host, s.port)
if not ok then
ngx.log(ngx.ERR, "failed to set current peer: " .. err)
return ngx.exit(500)
end
}
}
Functions
dyups.round_robin_server(service_name)
Get a backend server from the server list in a upstream, and using round-robin algorithm.
return a table:
{
host = "127.0.0.1",
port = 1234
}
dyups.all_servers(service_name)
Get all backend servers in a upstream.
return a table:
{
{host= "127.0.0.1", port = 1234},
{host= "127.0.0.2", port = 1234},
{host= "127.0.0.3", port = 1234}
}
So you can realize your own balance algorithms.
dyups.round_robin_with_weight(service_name)
Like round_robin_server, you should use this function instead of round_robin_serverZ().
This support peers weight.
Todo
--- Etcd cluster support.
--- Add more load-balance-alg.
--- Upstream peers weight support.
--- Upstream health check support.
License
I have not thought about it yet.