w3cschool-OpenResty 最佳实践Library
https://www.w3cschool.cn/openresty1/
OpenResty LRR 访问有授权验证的 Redis
2、不重启Redis设置密码：
在配置文件中配置requirepass的密码（当redis重启时密码依然有效）。
redis 127.0.0.1:6379> config set requirepass test123
查询密码：
redis 127.0.0.1:6379> config get requirepass
(error) ERR operation not permitted
密码验证：
redis 127.0.0.1:6379> auth test123
OK
再次查询：
redis 127.0.0.1:6379> config get requirepass
1) "requirepass"
2) "test123"
PS：如果配置文件中没添加密码 那么redis重启后，密码失效；
对于有授权验证的 Redis，正确的认证方法，请参考下面例子：
server {
location /test {
content_by_lua_block {
local redis = require "resty.redis"
local red = redis:new()
red:set_timeout(1000) -- 1 sec
local ok, err = red:connect("127.0.0.1", 6379)
if not ok then
ngx.say("failed to connect: ", err)
return
end
-- 请注意这里 auth 的调用过程
local count
count, err = red:get_reused_times()
if 0 == count then
ok, err = red:auth("password")
if not ok then
ngx.say("failed to auth: ", err)
return
end
elseif err then
ngx.say("failed to get reused times: ", err)
return
end
ok, err = red:set("dog", "an animal")
if not ok then
ngx.say("failed to set dog: ", err)
return
end
ngx.say("set result: ", ok)
-- 连接池大小是100个，并且设置最大的空闲时间是 10 秒
local ok, err = red:set_keepalive(10000, 100)
if not ok then
ngx.say("failed to set keepalive: ", err)
return
end
}
}
}
这里解释一下 tcpsock:getreusedtimes() 方法，如果当前连接不是从内建连接池中获取的，该方法总是返回 0 ，也就是说，该连接还没有被使用过。如果连接来自连接池，那么返回值永远都是非零。所以这个方法可以用来确认当前连接是否来自池子。
对于 Redis 授权，实际上只需要建立连接后，首次认证一下，后面只需直接使用即可。换句话说，从连接池中获取的连接都是经过授权认证的，只有新创建的连接才需要进行授权认证。所以大家就看到了 count, err = red:get_reused_times() 这段代码，并有了下面 if 0 == count then 的判断逻辑。
OpenResty Redis 接口的二次封装
先看一下官方的调用示例代码：
local redis = require "resty.redis"
local red = redis:new()
red:set_timeout(1000) -- 1 sec
local ok, err = red:connect("127.0.0.1", 6379)
if not ok then
ngx.say("failed to connect: ", err)
return
end
ok, err = red:set("dog", "an animal")
if not ok then
ngx.say("failed to set dog: ", err)
return
end
ngx.say("set result: ", ok)
-- put it into the connection pool of size 100,
-- with 10 seconds max idle time
local ok, err = red:set_keepalive(10000, 100)
if not ok then
ngx.say("failed to set keepalive: ", err)
return
end
这是一个标准的 Redis 接口调用，如果你的代码中 Redis 被调用频率不高，那么这段代码不会有任何问题。但如果你的项目重度依赖 Redis，工程中有大量的代码在重复创建连接-->数据操作-->关闭连接（或放到连接池）这个完整的链路调用完毕，甚至还要考虑不同的 return 情况做不同处理，就很快发现代码中有大量的重复。
Lua 是不支持面向对象的。很多人用尽各种招术利用元表来模拟。可是，Lua 的发明者似乎不想看到这样的情形，因为他们把取长度的 __len 方法以及析构函数 __gc 留给了 C API，纯 Lua 只能望洋兴叹。
我们期望的代码应该是这样的：
local red = redis:new()
local ok, err = red:set("dog", "an animal")
if not ok then
ngx.say("failed to set dog: ", err)
return
end
ngx.say("set result: ", ok)
local res, err = red:get("dog")
if not res then
ngx.say("failed to get dog: ", err)
return
end
if res == ngx.null then
ngx.say("dog not found.")
return
end
ngx.say("dog: ", res)
期望它自身具备以下几个特征：
- new、connect 函数合体，使用时只负责申请，尽量少关心什么时候具体连接、释放；
- 默认 Redis 数据库连接地址，但是允许自定义；
- 每次 Redis 使用完毕，自动释放 Redis 连接到连接池供其他请求复用；
- 要支持 Redis 的重要优化手段 pipeline；
不卖关子，只要干货，我们最后是这样干的，可以这里看到 gist代码
-- file name: resty/redis_iresty.lua
local redis_c = require "resty.redis"
local ok, new_tab = pcall(require, "table.new")
if not ok or type(new_tab) ~= "function" then
new_tab = function (narr, nrec) return {} end
end
local _M = new_tab(0, 155)
_M._VERSION = '0.01'
local commands = {
"append", "auth", "bgrewriteaof",
"bgsave", "bitcount", "bitop",
"blpop", "brpop",
"brpoplpush", "client", "config",
"dbsize",
"debug", "decr", "decrby",
"del", "discard", "dump",
"echo",
"eval", "exec", "exists",
"expire", "expireat", "flushall",
"flushdb", "get", "getbit",
"getrange", "getset", "hdel",
"hexists", "hget", "hgetall",
"hincrby", "hincrbyfloat", "hkeys",
"hlen",
"hmget", "hmset", "hscan",
"hset",
"hsetnx", "hvals", "incr",
"incrby", "incrbyfloat", "info",
"keys",
"lastsave", "lindex", "linsert",
"llen", "lpop", "lpush",
"lpushx", "lrange", "lrem",
"lset", "ltrim", "mget",
"migrate",
"monitor", "move", "mset",
"msetnx", "multi", "object",
"persist", "pexpire", "pexpireat",
"ping", "psetex", "psubscribe",
"pttl",
"publish", --[[ "punsubscribe", ]] "pubsub",
"quit",
"randomkey", "rename", "renamenx",
"restore",
"rpop", "rpoplpush", "rpush",
"rpushx", "sadd", "save",
"scan", "scard", "script",
"sdiff", "sdiffstore",
"select", "set", "setbit",
"setex", "setnx", "setrange",
"shutdown", "sinter", "sinterstore",
"sismember", "slaveof", "slowlog",
"smembers", "smove", "sort",
"spop", "srandmember", "srem",
"sscan",
"strlen", --[[ "subscribe", ]] "sunion",
"sunionstore", "sync", "time",
"ttl",
"type", --[[ "unsubscribe", ]] "unwatch",
"watch", "zadd", "zcard",
"zcount", "zincrby", "zinterstore",
"zrange", "zrangebyscore", "zrank",
"zrem", "zremrangebyrank", "zremrangebyscore",
"zrevrange", "zrevrangebyscore", "zrevrank",
"zscan",
"zscore", "zunionstore", "evalsha"
}
local mt = { __index = _M }
local function is_redis_null( res )
if type(res) == "table" then
for k,v in pairs(res) do
if v ~= ngx.null then
return false
end
end
return true
elseif res == ngx.null then
return true
elseif res == nil then
return true
end
return false
end
-- change connect address as you need
function _M.connect_mod( self, redis )
redis:set_timeout(self.timeout)
return redis:connect("127.0.0.1", 6379)
end
function _M.set_keepalive_mod( redis )
-- put it into the connection pool of size 100, with 60 seconds max idle time
return redis:set_keepalive(60000, 1000)
end
function _M.init_pipeline( self )
self._reqs = {}
end
function _M.commit_pipeline( self )
local reqs = self._reqs
if nil == reqs or 0 == #reqs then
return {}, "no pipeline"
else
self._reqs = nil
end
local redis, err = redis_c:new()
if not redis then
return nil, err
end
local ok, err = self:connect_mod(redis)
if not ok then
return {}, err
end
redis:init_pipeline()
for _, vals in ipairs(reqs) do
local fun = redis[vals[1]]
table.remove(vals , 1)
fun(redis, unpack(vals))
end
local results, err = redis:commit_pipeline()
if not results or err then
return {}, err
end
if is_redis_null(results)