📦 fffonion / lua-resty-shdict-server

Name ====

lua-resty-shdict-tool - An interface for debugging and serving ngx.shared dictionaries

Table of Contents =================

• Description
• Status
• Synopsis
• API
• Commands

• Basic commands

• AUTH

• SELECT

• PING

• KEYS

• EVAL
• Known Issues
• TODO
• Copyright and License
• See Also

Description ===========

This is a tool to provide a redis-cli-like interface to debug ngx.shared.DICT API.

It can also be used as a mocking Redis server (WIP).

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Status ========

Experimental.

Synopsis ========

Shared dictionaries defined in http and stream subsystems are not shared to each other, thus we need two sets of configurations to debug with either subsystem. Despite from this, this module provide a similar API to use in both subsystems.

http

---

lua_shared_dict dogs 10m;

server {
    listen 80;
    
    location =/cli {
        content_by_lua_block {
            require "resty.core"
            local srv = require("resty.shdict.server")
            local s = srv:new("foobar", nil)
            s:serve()
        }
    }
}

This sets up a simple HTTP server. Use any http client like curl to issue a http request to the location we configured. For example:

$ curl "http://host/cli?dict=dogs&cmd=set%20dog%20wow&password=foobar"
OK

$ curl "http://host/cli?dict=dogs&cmd=get%20dog&password=foobar"
"wow"

stream

---

lua_shared_dict dogs 10m;

server {
    listen 127.0.0.1:18001;
    content_by_lua_block {
        require "resty.core.shdict"
        local srv = require("resty.shdict.server")
        local s = srv:new("foobar", nil)
        s:serve()
    }
}

This sets up a simple TCP server. Use telnet or equivalent tools to connect interactively. For example:

$ telnet 127.0.0.1 18001
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
SELECT dogs
ERR authentication required
AUTH foobar
OK
SELECT dogs
OK
SET dog wow
OK
GET dog
"wow"

Also it supports Redis RESP protocol.

$ redis-cli -h 127.0.0.1 -p 18001
127.0.0.1:18001> get dogs
(error) ERR authentication required
127.0.0.1:18001> auth foobar
OK
127.0.0.1:18001> set dog wow
(error) ERR no shdict selected
127.0.0.1:18001> select dogs
OK
127.0.0.1:18001> set dog wow
OK
127.0.0.1:18001> get dog
wow

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API =======

shdict.server:new(password, shdict)

---

Initialize the server instance with password and pre-selected shared dictionary shdict.

If password is not set, the server is public. If password is set, client must call auth command to authenticate before running other commands. Please take proper security measurements if you're listening to non-local interfaces.

If shdict is not set, client must call select command to select a shared dictionary.

shdict.server:serve(mode)

---

Start the server with handler named mode. To run handler servestreamredis, use: %%CODEBLOCK5%% If *mode* is not defined, default handler for each subsystem is used. For http the default handler is servehttpplain. For stream the default handler is servestreamredis. shdict.server:serve_http_plain() -------------------------------- This handler accept a single HTTP request from client and send the response back in plain text. shdict.server:serve_http_json() ------------------------------- This handler accept a single HTTP request from client and send the response back in json encoded text. shdict.server:serve_http(output_filter) --------------------------------------- This handler accept a single HTTP request from client and send the response formatted by outputfilter. If outputfilter is not defined, **output_plain** is used and this handler is equivalent to servehttpplain. outputfilter is a function that takes a table as argument and returns a string. User can define their own filter and genereate desirable output. shdict.server:serve_stream_redis() ---------------------------------- This handler accept TCP connection in inline or Redis protocol. A plain text TCP client like telnet or nc or a Redis-compatible client or library can be used to connect to the server. [Back to TOC](#table-of-contents) Commands ======= Basic commands ------------- Methods from ngx.shared.DICT API are supported. * [ngx.shared.DICT](https://github.com/openresty/lua-nginx-module#ngxshareddict) * [ngx.shared.DICT.get](https://github.com/openresty/lua-nginx-module#ngxshareddictget) * [ngx.shared.DICT.get_stale](https://github.com/openresty/lua-nginx-module#ngxshareddictget_stale) * [ngx.shared.DICT.set](https://github.com/openresty/lua-nginx-module#ngxshareddictset) * [ngx.shared.DICT.safe_set](https://github.com/openresty/lua-nginx-module#ngxshareddictsafe_set) * [ngx.shared.DICT.add](https://github.com/openresty/lua-nginx-module#ngxshareddictadd) * [ngx.shared.DICT.safe_add](https://github.com/openresty/lua-nginx-module#ngxshareddictsafe_add) * [ngx.shared.DICT.replace](https://github.com/openresty/lua-nginx-module#ngxshareddictreplace) * [ngx.shared.DICT.delete](https://github.com/openresty/lua-nginx-module#ngxshareddictdelete) * [ngx.shared.DICT.incr](https://github.com/openresty/lua-nginx-module#ngxshareddictincr) * [ngx.shared.DICT.lpush](https://github.com/openresty/lua-nginx-module#ngxshareddictlpush) * [ngx.shared.DICT.rpush](https://github.com/openresty/lua-nginx-module#ngxshareddictrpush) * [ngx.shared.DICT.lpop](https://github.com/openresty/lua-nginx-module#ngxshareddictlpop) * [ngx.shared.DICT.rpop](https://github.com/openresty/lua-nginx-module#ngxshareddictrpop) * [ngx.shared.DICT.llen](https://github.com/openresty/lua-nginx-module#ngxshareddictllen) * [ngx.shared.DICT.ttl](https://github.com/openresty/lua-nginx-module#ngxshareddictttl) * [ngx.shared.DICT.expire](https://github.com/openresty/lua-nginx-module#ngxshareddictexpire) * [ngx.shared.DICT.flush_all](https://github.com/openresty/lua-nginx-module#ngxshareddictflush_all) * [ngx.shared.DICT.flush_expired](https://github.com/openresty/lua-nginx-module#ngxshareddictflush_expired) * [ngx.shared.DICT.get_keys](https://github.com/openresty/lua-nginx-module#ngxshareddictget_keys) * [ngx.shared.DICT.capacity](https://github.com/openresty/lua-nginx-module#ngxshareddictcapacity) * [ngx.shared.DICT.free_space](https://github.com/openresty/lua-nginx-module#ngxshareddictfree_space) Some of the commands like ttl and capacity require the resty.core being installed. To use these commands, put require('resty.core') for http subsystem and require('resty.core.shdict') for stream subsystem. Methods names are **case-insensitive**. Arguments are seperated by spaces. For example: - To set a value **wow** with key **dog**, use SET dog wow or sEt dog wow. - To set a value **wow !** with key **dog**, use SET dog "wow !". - To set a value **"wow" !** with key **dog**, use SET dog "\"wow\" !". Some commands are mapped to redis-flavoured commands if resty.shdict.redis-commands is included. - del as an alias of delete - flushall as an alias of flushall AUTH ---- Authenticate to the server. %%CODEBLOCK6%% Returns **OK** if *password* is valid. SELECT ------ Select a shared dictionary. %%CODEBLOCK7%% Returns **OK** if *shdict* is found. PING ---- Test connection to the server. %%CODEBLOCK8%% KEYS ---- This command requires the resty.shdict.redis-commands module. The time complexity is **O(3n)**. This command is for debug only, please do not use in production code to search for keys. Returns all keys matching *pattern* in a list. The *pattern* is a glob-style pattern. %%CODEBLOCK9%% Returns a list of all keys found. EVAL ---- This command requires the resty.shdict.redis-commands module. Run a Lua script on the server. The syntax is same with Redis [EVAL](https://redis.io/commands/eval). %%CODEBLOCK10%% For security reasons, only the following APIs are available: - ngx. APIs except for ngx.shared and ngx.re - shdict.call and shdict.pcall - zone as the current shdict instance Also an alias from shdict.call to redis.call is created for convenience. [Back to TOC](#table-of-contents) Known Issues ==== - The library will use resty.core if it's installed, the behaviour will be slightly different from the C implementation. For example, missing arguments will be filled by nil when using resty.core, issuing SET a is equivalent to SET a nil in this situation. - For performance issues, inline protocol (HTTP inline or Redis inline) only accept four arguments at most. EVAL` may fail with Invalid argument(s) for this reason. To solve this, always use other protocols (like Redis RESP protocol) to call these commands.

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TODO ====

• Add INFO command.

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Copyright and License =====================

This module is licensed under the BSD license.

Copyright (C) 2018, by fffonion .

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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See Also ========

• openresty/lua-nginx-module

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