I am beginner in LUA. I have written the following code in lua file that mysql proxy run with it.
function read_query(packet)
if string.byte(packet) == proxy.COM_QUERY then
local command = string.lower(packet)
if string.find(command, "select") ~= nil and string.find(string.lower(packet), "from") ~= nil then
local socket = require('socket')
local conn, err = socket.connect('localhost', 5050)
print(conn, err)
proxy.response.type = proxy.MYSQLD_PACKET_OK
//proxy.response.resultset get json from web service (url)
proxy.response.resultset = {
fields = {
{ type = proxy.MYSQL_TYPE_INT, name = "id", },
},
rows = {
{ 9001 }
}
}
return proxy.PROXY_SEND_RESULT
end
end
end
I want to connect to the web service on Port 5050 that return the JSON file and save the json that it returns in the proxy.response.resultset.
Another question, How can i add socket module. I paste files like following image
socket module files
but give an error : can not find /socket/core.lua.
local socket = require('socket')
You are using luasocket and it comes as a mix of lua (socket.lua) and binary (socket/core.so) files. You need to set (if it's not set already) to point to .so files; something like this may work: package.cpath=package.cpath..';./?.so'
Related
I am new in ruby on rails and I want to read data from a JSON file from a specified directory, but I constantly get an error in chap3(File name)
Errno::ENOENT in TopController#chap3. No such file or directory # rb_sysopen - links.json.
In the console, I get a message
Failed to load resource: the server responded with a status of 500 (Internal Server Error)
How I can fix that?
Code:
require "json"
class TopController < ApplicationController
def index
#message = "おはようございます！"
end
def chap3
data = File.read('links.json')
datahash = JSON.parse(data)
puts datahash.keys
end
def getName
render plain: "名前は、#{params[:name]}"
end
def database
#members = Member.all
end
end
JSON file:
{ "data": [
{"link1": "http://localhost:3000/chap3/a.html"},
{"link2": "http://localhost:3000/chap3/b.html"},
{"link3": "http://localhost:3000/chap3/c.html"},
{"link4": "http://localhost:3000/chap3/d.html"},
{"link5": "http://localhost:3000/chap3/e.html"},
{"link6": "http://localhost:3000/chap3/f.html"},
{"link7": "http://localhost:3000/chap3/g.html"}]}
I would change these two lines
data = File.read('links.json')
datahash = JSON.parse(data)
in the controller to
datahash = Rails.root.join('app/controllers/links.json').read
Note: I would consider moving this kind of configuration file into the /config folder and creating a simple Ruby class to handle it. Additionally, you might want to consider paths instead of URLs with a host because localhost:3000 might work in the development environment but in production, you will need to return non-localhost URLs anyway.
Rails use the content of file in the controller
#data = File.read("#{Rails.root}/app/controllers/links.json")
I am new to lua and i am trying to make a function that receives documents and outputs a table but I am getting the above error. Why??
io.write("How many documents are we evaluating? \nInput: ")
local total_documents=io.read("*n")
io.read()
local docTable = {}
inputDocument()
function inputDocument()
local input
local file
local inputFile = {filename = nil, contents = nil, wordcount = nil}
repeat
io.write("Please enter document (filename.extension): ")
input = io.read()
file =io.open(input)
if file == nil then
print("File does not exist try again")
end
until(file ~=nil)
inputFile.filename = input
return inputFile
end
You need to define inputDocument before using it:
function inputDocument()
...
end
io.write("How many documents are we evaluating? \nInput: ")
...
inputDocument()
What I have:
GNU/Linux host
nginx is up and running
there is a cron-job scheduled to run immediately after a specific file has been removed (similar to run-crons)
GitHub sends a webhook when someone pushes to a repository
What I want:
I do now want to run either lua or anything comparable to parse GitHub's request and validate it and then delete a file (if the request was valid of course).
Preferably all of this should happen without the hassle to maintain an additional PHP installation as there is currently none, or the need to use fcgiwrap or similar.
Template:
On the nginx side I have something equivalent to
location /deploy {
# execute lua (or equivalent) here
}
To read json body of GH webhook you nead use JSON4Lua lib, and to validate HMAC signature use luacrypto.
Preconfigure
Install required modules
$ sudo luarocks install JSON4Lua
$ sudo luarocks install luacrypto
In Nginx define location for deploy
location /deploy {
client_body_buffer_size 3M;
client_max_body_size 3M;
content_by_lua_file /path/to/handler.lua;
}
The max_body_size and body_buffer_size should be equal to prevent error
request body in temp file not supported
https://github.com/openresty/lua-nginx-module/issues/521
Process webhook
Get request payload data and check is correct
ngx.req.read_body()
local data = ngx.req.get_body_data()
if not data then
ngx.log(ngx.ERR, "failed to get request body")
return ngx.exit (ngx.HTTP_BAD_REQUEST)
end
Verify GH signature with use luacrypto
local function verify_signature (hub_sign, data)
local sign = 'sha1=' .. crypto.hmac.digest('sha1', data, secret)
-- this is simple comparison, but it's better to use a constant time comparison
return hub_sign == sign
end
-- validate GH signature
if not verify_signature(headers['X-Hub-Signature'], data) then
ngx.log(ngx.ERR, "wrong webhook signature")
return ngx.exit (ngx.HTTP_FORBIDDEN)
end
Parse data as json and check is master branch, for deploy
data = json.decode(data)
-- on master branch
if data['ref'] ~= branch then
ngx.say("Skip branch ", data['ref'])
return ngx.exit (ngx.HTTP_OK)
end
If all correct, call deploy function
local function deploy ()
-- run command for deploy
local handle = io.popen("cd /path/to/repo && sudo -u username git pull")
local result = handle:read("*a")
handle:close()
ngx.say (result)
return ngx.exit (ngx.HTTP_OK)
end
Example
Example constant time string compare
local function const_eq (a, b)
-- Check is string equals, constant time exec
getmetatable('').__index = function (str, i)
return string.sub(str, i, i)
end
local diff = string.len(a) == string.len(b)
for i = 1, math.min(string.len(a), string.len(b)) do
diff = (a[i] == b[i]) and diff
end
return diff
end
A complete example of how I use it in github gist https://gist.github.com/Samael500/5dbdf6d55838f841a08eb7847ad1c926
This solution does not implement verification for GitHub's hooks and assumes you have the lua extension and the cjson module installed:
location = /location {
default_type 'text/plain';
content_by_lua_block {
local cjson = require "cjson.safe"
ngx.req.read_body()
local data = ngx.req.get_body_data()
if
data
then
local obj = cjson.decode(data)
if
# checksum checking should go here
(obj and obj.repository and obj.repository.full_name) == "user/reponame"
then
local file = io.open("<your file>","w")
if
file
then
file:close()
ngx.say("success")
else
ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
end
else
ngx.exit(ngx.HTTP_UNAUTHORIZED)
end
else
ngx.exit(ngx.HTTP_NOT_ALLOWED)
end
}
}
I compiled Bind 9 from source (see below) and set up Bind9 with MySQL DLZ.
I keep getting an error when I attempt to fetch anything from the server about buffer overflow. I've googled many times but can not find anything on how to fix this error.
Configure options:
root#anacrusis:/opt/bind9/bind-9.9.1-P3# named -V BIND 9.9.1-P3 built
with '--prefix=/opt/bind9' '--mandir=/opt/bind9/man'
'--infodir=/opt/bind9/info' '--sysconfdir=/opt/bind9/config'
'--localstatedir=/opt/bind9/var' '--enable-threads'
'--enable-largefile' '--with-libtool' '--enable-shared'
'--enable-static' '--with-openssl=/usr' '--with-gssapi=/usr'
'--with-gnu-ld' '--with-dlz-postgres=no' '--with-dlz-mysql=yes'
'--with-dlz-bdb=no' '--with-dlz-filesystem=yes' '--with-dlz-stub=yes'
'--with-dlz-ldap=yes' '--enable-ipv6' 'CFLAGS=-fno-strict-aliasing
-DDIG_SIGCHASE -O2' 'LDFLAGS=-Wl,-Bsymbolic-functions' 'CPPFLAGS=' using OpenSSL version: OpenSSL 1.0.1 14 Mar 2012 using libxml2
version: 2.7.8
This is the error I get when I dig example.com (with debug):
Query String: select ttl, type, mx_priority, case when
lower(type)='txt' then concat('"', data, '"')
else data end from dns_records where zone = 'example.com' and host = '#'
17-Sep-2012 01:09:33.610 dns_rdata_fromtext: buffer-0x7f5bfca73360:1:
unexpected end of input 17-Sep-2012 01:09:33.610 dns_sdlz_putrr
returned error. Error code was: unexpected end of input 17-Sep-2012
01:09:33.610 Query String: select ttl, type, mx_priority, case when
lower(type)='txt' then concat('"', data, '"')
else data end from dns_records where zone = 'example.com' and host = '*'
17-Sep-2012 01:09:33.610 query.c:2579: fatal error: 17-Sep-2012
01:09:33.610 RUNTIME_CHECK(result == 0) failed 17-Sep-2012
01:09:33.610 exiting (due to fatal error in library)
Named.conf
options {
directory "/opt/bind9/";
allow-query-cache { none; };
allow-query { any; };
recursion no;
};
dlz "Mysql zone" {
database "mysql
{host=localhost dbname=system ssl=false user=root pass=*password*}
{select zone from dns_records where zone = '$zone$'}
{select ttl, type, mx_priority, case when lower(type)='txt' then concat('\"', data, '\"')
else data end from dns_records where zone = '$zone$' and host = '$record$'}
{}
{}
{}
{}";
};
Do you run named single-threaded (with "-n 1" parameter)? If not, named will crash in various places when working on more than one query in parallel, since the MySQL DLZ module is not thread safe.
Manually log into the DB and run the query. See what it comes up with. The error says it's got an unexpected end of input, meaning it was expecting to get something and it never got it. So the first thing is to see if it you can get it manually. Maybe the mysqld isn't running. Maybe the user isn't defined or password is set wrong or permissions are not granted on that table. These could all account for the error.
Assuming all this works then you have two options: Enable more logging in your named.conf so you have more data to work with on what's happeningRemove and reinstall BIND, ensuring that all hashes match on all libraries and that all dependancies are in place.
I have gotten Bind with DLZ working on CentOS 7. I do not get the error that is effecting you.
I realize this is an older post but I thought I would share my conf files , and configure options.
I am using Bind 9.11.0
configure
./configure --prefix=/usr --sysconfdir=/etc/bind --localstatedir=/var --mandir=/usr/share/man --infodir=/usr/share/info --enable-threads --enable-largefile --with-libtool --enable-shared --enable-static --with-openssl=/usr --with-gssapi=/usr --with-gnu-ld --with-dlz-postgres=no --with-dlz-mysql=yes --with-dlz-bdb=no --with-dlz-filesystem=yes --with-dlz-stub=yes --enable-ipv6
named.conf
// This is the primary configuration file for the BIND DNS server named.
//
// Please read /usr/share/doc/bind9/README.Debian.gz for information on the
// structure of BIND configuration files in Debian, *BEFORE* you customize
// this configuration file.
//
// If you are just adding zones, please do that in /etc/bind/named.conf.local
#auskommentiert !!!
#include "/etc/bind/named.conf.options";
#include "/etc/bind/named.conf.local";
#include "/etc/bind/named.conf.default-zones";
key "rndc-key" {
// how was key encoded
algorithm hmac-md5;
// what is the pass-phrase for the key
secret "noway";
};
#options {
#default-key "rndc-key";
#default-server 127.0.0.1;
#default-port 953;
#};
controls {
inet * port 953 allow { any; } keys { "rndc-key"; };
#inet * port 53 allow { any; } keys { "rndc-key"; };
};
logging {
channel query.log {
file "/var/log/query.log";
// Set the severity to dynamic to see all the debug messages.
severity dynamic;
};
category queries { query.log; };
};
dlz "Mysql zone" {
database "mysql
{host=172.16.254.100 port=3306 dbname=dyn_server_db user=db_user pass=db_password}
{SELECT zone FROM dyn_dns_records WHERE zone = '$zone$'}
{SELECT ttl, type, mx_priority, IF(type = 'TXT', CONCAT('\"',data,'\"'), data) AS data
FROM dyn_dns_records
WHERE zone = '$zone$' AND host = '$record$' AND type <> 'SOA' AND type <> 'NS'}
{SELECT ttl, type, data, primary_ns, resp_person, serial, refresh, retry, expire, minimum
FROM dyn_dns_records
WHERE zone = '$zone$' AND (type = 'SOA' OR type='NS')}
{SELECT ttl, type, host, mx_priority, IF(type = 'TXT', CONCAT('\"',data,'\"'), data) AS data, resp_person, serial, refresh, retry, expire, minimum
FROM dyn_dns_records
WHERE zone = '$zone$' AND type <> 'SOA' AND type <> 'NS'}
{SELECT zone FROM xfr_table where zone='$zone$' AND client = '$client$'}";
};
hi i have found a tutorial on how to use post json in lua.
here is the code :
http = require("socket.http")
crypto = require("crypto")
ltn12 = require("ltn12")
url = require("socket.url")
local json = require("json")
local commands_json =
{
["message"] = "Hello",
}
print (commands_json)
local json = {}
json.api_key = "6_192116334"
json.ver = 1
json.commands_json = json.encode(commands_json)
json.commands_hash = crypto.digest(crypto.md5, json.commands_json .. 'hkjhkjhkjh')
local post = "api=" .. url.escape(Json.Encode(json))
local response = {}
local r, c, h = http.request {
url = "http://127.0.0.1/?page=api",
method = "POST",
headers = {
["content-length"] = #post,
["Content-Type"] = "application/x-www-form-urlencoded"
},
source = ltn12.source.string(post),
sink = ltn12.sink.table(response)
}
local path = system.pathForFile("r.txt", system.DocumentsDirectory)
local file = io.open (path, "w")
file:write (Json.Encode(json) .. "\n")
file:write (post .. "\n")
file:write (response[1] .. "\n")
io.close (file)
json = Json.Decode(table.concat(response,''))
native.showAlert("hey", json.commands[1].tot_nbr_rows)
now i got these error:
Windows simulator build date: Dec 9 2011 # 14:01:29
Copyright (C) 2009-2011 A n s c a , I n c .
Version: 2.0.0
Build: 2011.704
table: 0346D6D0
Runtime error
...nistrator\my documents\corona projects\json\main.lua:17: attempt to c
all field 'encode' (a nil value)
stack traceback:
[C]: in function 'encode'
...nistrator\my documents\corona projects\json\main.lua:17: in main chun
k
Runtime error: ...nistrator\my documents\corona projects\json\main.lua:17: attem
pt to call field 'encode' (a nil value)
stack traceback:
[C]: in function 'encode'
...nistrator\my documents\corona projects\json\main.lua:17: in main chun
k
i don't know why i got the error from encode.
can anyone can help me about my case?
thanks in advance ...
This includes the Json code provided externally, likely with an encode function:
local json = require("json")
This throws away your old json variable and replaces it with an empty table:
local json = {}
And this tries to call json.encode which is now undefined since you redefined json as an empty table above:
json.commands_json = json.encode(commands_json)
The solution is to pick a different variable name.