pulling table with redis on lua - nginx

Question

I'm running LUA on Nginx. I decided to fetch some variables via Redis. I am using a table on lua. It is like this;
local ip_blacklist = {
"1.1.1.1",
"1.1.1.2",
}
I'm printing on Nginx;
1.1.1.1
1.1.1.2
I want to keep the values here on Redis and not on Lua. My redis : http://prntscr.com/10sv3ln
My Lua command;
local ip = red:hmget("iplist", "ip_blacklist")
I'm printing on Nginx;
{"1.1.1.1","1.1.1.2",}
Its data does not come as a table and functions do not work. How can I call this data like local ip_blacklist?

Answer 1

https://redis.io/topics/data-types
Redis Hashes are maps between string fields and string values
You cannot store a Lua table as a hash value directly. As I understand, you have stored a literal string {"1.1.1.1","1.1.1.2",} using RedisInsight, but it doesn't work that way.
You can use JSON for serialization:
server {
location / {
content_by_lua_block {
local redis = require('resty.redis')
local json = require('cjson.safe')
local red = redis:new()
red:connect('127.0.0.1', 6379)
-- set a string with a JSON array as a hash value; you can use RedisInsight for this step
red:hset('iplist', 'ip_blacklist', '["1.1.1.1", "1.1.1.2"]')
-- read a hash value as a string (a serialized JSON array)
local ip_blacklist_json = red:hget('iplist', 'ip_blacklist')
-- decode the JSON array to a Lua table
local ip_blacklist = json.decode(ip_blacklist_json)
ngx.say(type(ip_blacklist))
for _, ip in ipairs(ip_blacklist) do
ngx.say(ip)
end
}
}
}
Output:
table
1.1.1.1
1.1.1.2