print method in lua script/redis is not working - docker

Question

I am trying to execute the following script and getting the below error. Redis is running in docker
Exception in thread "main" org.redisson.client.RedisException: ERR
user_script:1: Script attempted to access nonexistent global variable
'print' script: 6f736423f082e141036b833d1f86b5a36a494611, on
#user_script:1..
I get the same error when I execute using redis CLI
127.0.0.1:6379> eval "print("Comparison is_made b/w minimum_value out of two is: ")" 0 (error) ERR user_script:1: Script attempted to
access nonexistent global variable 'print' script:
8598b7f0db450c711d3a9e73a296e331bd1ef945, on #user_script:1.
127.0.0.1:6379>
Java code. I am using Redison lib to connect to Redis and execute script.
String script = "local rate = redis.call('hget', KEYS[1], 'rate');"
+ "local interval = redis.call('hget', KEYS[1], 'interval');"
+ "local type = redis.call('hget', KEYS[1], 'type');"
+ "assert(rate ~= false and interval ~= false and type ~= false, 'RateLimiter is not initialized')"
+ "local valueName = KEYS[2];"
+ "local permitsName = KEYS[4];"
+ "if type == '1' then "
+ "valueName = KEYS[3];"
+ "permitsName = KEYS[5];"
+ "end;"
+"print(\"rate\"..rate) ;"
+"print(\"interval\"..interval) ;"
+"print(\"type\"..type); "
+ "assert(tonumber(rate) >= tonumber(ARGV[1]), 'Requested permits amount could not exceed defined rate'); "
+ "local currentValue = redis.call('get', valueName); "
+ "local res;"
+ "if currentValue ~= false then "
+ "local expiredValues = redis.call('zrangebyscore', permitsName, 0, tonumber(ARGV[2]) - interval); "
+ "local released = 0; "
+ "for i, v in ipairs(expiredValues) do "
+ "local random, permits = struct.unpack('Bc0I', v);"
+ "released = released + permits;"
+ "end; "
+ "if released > 0 then "
+ "redis.call('zremrangebyscore', permitsName, 0, tonumber(ARGV[2]) - interval); "
+ "if tonumber(currentValue) + released > tonumber(rate) then "
+ "currentValue = tonumber(rate) - redis.call('zcard', permitsName); "
+ "else "
+ "currentValue = tonumber(currentValue) + released; "
+ "end; "
+ "redis.call('set', valueName, currentValue);"
+ "end;"
+ "if tonumber(currentValue) < tonumber(ARGV[1]) then "
+ "local firstValue = redis.call('zrange', permitsName, 0, 0, 'withscores'); "
+ "res = 3 + interval - (tonumber(ARGV[2]) - tonumber(firstValue[2]));"
+ "else "
+ "redis.call('zadd', permitsName, ARGV[2], struct.pack('Bc0I', string.len(ARGV[3]), ARGV[3], ARGV[1])); "
+ "redis.call('decrby', valueName, ARGV[1]); "
+ "res = nil; "
+ "end; "
+ "else "
+ "redis.call('set', valueName, rate); "
+ "redis.call('zadd', permitsName, ARGV[2], struct.pack('Bc0I', string.len(ARGV[3]), ARGV[3], ARGV[1])); "
+ "redis.call('decrby', valueName, ARGV[1]); "
+ "res = nil; "
+ "end;"
+ "local ttl = redis.call('pttl', KEYS[1]); "
+ "if ttl > 0 then "
+ "redis.call('pexpire', valueName, ttl); "
+ "redis.call('pexpire', permitsName, ttl); "
+ "end; "
+ "return res;";
RedissonClient client = null;
try {
client = Redisson.create();
client.getRateLimiter("user1:endpoint1").setRate(
RateType.PER_CLIENT, 5, 1, RateIntervalUnit.SECONDS);
String sha1 = client.getScript().scriptLoad(script);
List<Object> keys =
Arrays.asList("user1:endpoint1", "{user1:endpoint1}:value",
"{user1:endpoint1}:value:febbb04d-6365-4cb8-b32b-8d90800cd4e6",
"{user1:endpoint1}:permits", "{user1:endpoint1}:permits:febbb04d-6365-4cb8-b32b-8d90800cd4e6");
byte[] random = new byte[8];
ThreadLocalRandom.current().nextBytes(random);
Object args[] = {1, System.currentTimeMillis(), random};
boolean res = client.getScript().evalSha(READ_WRITE, sha1, RScript.ReturnType.BOOLEAN, keys, 1,
System.currentTimeMillis(), random);
System.out.println(res);
}finally {
if(client != null && !client.isShutdown()){
client.shutdown();
}
}
checked the Lua print on the same line thread but io.write also is giving same error.

Answer 1

As in the comments wrote return() seems* the only way.
Example for redis-cli (set redis DB and use it in Lua)
(Collect Data and return as one string)
set LuaV 'local txt = "" for k, v in pairs(redis) do txt = txt .. tostring(k) .. " => " .. tostring(v) .. " | " end return(txt)'
Now the eval
eval "local f = redis.call('GET', KEYS[1]) return(loadstring(f))()" 1 LuaV
...shows whats in table: redis
(One long String no \n possible)
Exception: eval 'redis.log(2, _VERSION)' 0 gives out without ending the script but only on the server.
Than \n will work when you do...
set LuaV 'local txt = "" for k, v in pairs(redis) do txt = txt .. tostring(k) .. " => " .. tostring(v) .. "\n" end return(txt)'
...and the eval
eval 'local f = redis.call("GET", KEYS[1]) f = loadstring(f)() redis.log(2, f)' 1 LuaV