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https://github.com/zigzagak/ngx_zookeeper_lua
Nginx zookeeper lua module
https://github.com/zigzagak/ngx_zookeeper_lua
nginx nginx-service-discovery nginx-zookeeper zookeeper
Last synced: about 1 month ago
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Nginx zookeeper lua module
- Host: GitHub
- URL: https://github.com/zigzagak/ngx_zookeeper_lua
- Owner: ZigzagAK
- License: bsd-2-clause
- Created: 2016-11-05T20:03:51.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2024-08-21T08:40:26.000Z (5 months ago)
- Last Synced: 2024-08-21T09:59:40.972Z (5 months ago)
- Topics: nginx, nginx-service-discovery, nginx-zookeeper, zookeeper
- Language: C
- Size: 380 KB
- Stars: 46
- Watchers: 8
- Forks: 12
- Open Issues: 0
-
Metadata Files:
- Readme: README.markdown
- License: LICENSE
Awesome Lists containing this project
README
Name
====
ngx_zookeeper_lua - Lua bindings to interract with Zookeeper.
Build status
============
[](https://travis-ci.org/ZigzagAK/ngx_zookeeper_lua)
Table of Contents
=================
* [Name](#name)
* [Status](#status)
* [Synopsis](#synopsis)
* [Description](#description)
* [Install](#install)
* [Simple UI](#simple-ui)
* [Configuration directives](#configuration-directives)
* [Base methods](#methods)
* [connected](#connected)
* [get](#get)
* [childrens](#childrens)
* [set](#set)
* [create](#create)
* [delete](#delete)
* [delete_recursive](#delete_recursive)
* [tree](#tree)
* [watch](#watch)
* [watch_path](#watch_path)
* [watcher_exists](#watcher_exists)
* [unwatch](#unwatch)
* [Additional API](#additional-api)
* [api.tree](#api-tree)
* [api.import](#api-import)
Status
======
This library is production ready.
Description
===========
This module provides Lua bindings to interract with Zookeeper.
[Back to TOC](#table-of-contents)
Install
=======
Build nginx with Zookeeper support.
All dependencies are downloaded automaticaly.
```
git clone [email protected]:ZigzagAK/ngx_zookeeper_lua.git
cd ngx_zookeeper_lua
./build.sh
```
Archive will be placed in the `install` folder after successful build.
[Back to TOC](#table-of-contents)
Synopsis
========
```nginx
http {
zookeeper 127.0.0.1:2181;
zookeeper_log_level debug;
zookeeper_recv_timeout 5000;
zookeeper_ephemeral_node /services/nginx 127.0.0.1 "nginx";
lua_shared_dict config 64k;
lua_shared_dict zoo_cache 10m;
init_by_lua_block {
ngx.shared.config:set("zoo.cache.on", true)
ngx.shared.config:set("zoo.cache.ttl", 60)
ngx.shared.config:set("zoo.cache.path.ttl", '[' ..
'{ "path" : "/services/.*", "ttl" : 0 }' ..
']')
}
init_worker_by_lua_block {
assert(ngx.timer.at(1, function()
local zoo = require "zoo"
local cjson = require "cjson"
zoo.delete_recursive("/watched1")
zoo.delete_recursive("/watched2")
zoo.create("/watched1")
zoo.create("/watched2")
local function on_event(ctx)
local data = assert(zoo.watch(ctx.path, ctx.watcher_type, on_event, ctx))
ngx.log(ngx.INFO, "on_event: ", ctx.path, "=", cjson.encode(data))
end
on_event {
watcher_type = zoo.WatcherType.DATA,
path = "/watched1"
}
on_event {
watcher_type = zoo.WatcherType.DATA,
path = "/watched2"
}
on_event {
watcher_type = zoo.WatcherType.CHILDREN,
path = "/watched1"
}
on_event {
watcher_type = zoo.WatcherType.CHILDREN,
path = "/watched2"
}
local stop
assert(ngx.timer.at(60, function()
assert(zoo.unwatch("/watched1", zoo.WatcherType.DATA))
assert(zoo.unwatch("/watched1", zoo.WatcherType.CHILDREN))
assert(zoo.unwatch("/watched2", zoo.WatcherType.DATA))
assert(zoo.unwatch("/watched2", zoo.WatcherType.CHILDREN))
ngx.log(ngx.INFO, "unwatch")
stop = ngx.now() + 10
end))
local i = 0
local function change(premature)
if premature or (stop and stop < ngx.now()) then
return
end
pcall(function()
if zoo.connected() then
i = i + 1
assert(zoo.set("/watched1", i))
assert(zoo.set("/watched2", i))
if i % 2 == 1 then
assert(zoo.create("/watched1/1"))
assert(zoo.create("/watched2/1"))
else
assert(zoo.delete("/watched1/1"))
assert(zoo.delete("/watched2/1"))
end
ngx.log(ngx.INFO, "update")
end
end)
assert(ngx.timer.at(1, change))
end
assert(ngx.timer.at(1, change))
end))
}
server {
listen 8000;
zookeeper_register_port /services/nginx/8000 8000 "nginx-8080";
location / {
return 200 '8000';
}
}
server {
listen 8001;
location /a {
zookeeper_ephemeral_node /services/nginx/8001/a 127.0.0.1:8001;
return 200 '8001:a';
}
location /b {
zookeeper_ephemeral_node /services/nginx/8001/b 127.0.0.1:8001;
return 200 '8001:b';
}
}
server {
listen 12181;
include mime.types;
default_type application/json;
root html/zoo;
index index.html;
server_name zoo;
location = /get {
content_by_lua_block {
local zoo = require "zoo"
local cjson = require "cjson"
local value, stat, err = zoo.get(ngx.var.arg_znode)
ngx.say(cjson.encode(value and { value = value, stat = stat } or { error = err }))
}
}
location = /childrens {
content_by_lua_block {
local zoo = require "zoo"
local cjson = require "cjson"
local childs, err = zoo.childrens(ngx.var.arg_znode)
ngx.say(cjson.encode(childs and childs or { error = err }))
}
}
location = /set {
content_by_lua_block {
local zoo = require "zoo"
local cjson = require "cjson"
local stat, err = zoo.set(ngx.var.arg_znode, ngx.var.arg_value, ngx.var.arg_version)
ngx.say(cjson.encode(stat and { value = ngx.var.arg_value, stat = stat } or { error = err }))
}
}
location = /create {
content_by_lua_block {
local zoo = require "zoo"
local cjson = require "cjson"
local result, err = zoo.create(ngx.var.arg_znode, ngx.var.arg_value)
ngx.say(cjson.encode(result and { znode = result } or { error = err }))
}
}
location = /delete {
content_by_lua_block {
local zoo = require "zoo"
local cjson = require "cjson"
local ok, err = zoo.delete(ngx.var.arg_znode)
ngx.say(cjson.encode(ok and { znode = "deleted" } or { error = err }))
}
}
location = /tree {
content_by_lua_block {
local api = require "zoo.api"
local cjson = require "cjson"
ngx.say(cjson.encode(api.tree(ngx.var.arg_znode,
ngx.var.arg_stat and ngx.var.arg_stat:match("[1yY]"))))
}
}
location = /import {
content_by_lua_block {
local api = require "zoo.api"
local method = ngx.req.get_method()
if method ~= "POST" and method ~= "PUT" then
ngx.exit(ngx.HTTP_BAD_REQUEST)
end
local content_type = ngx.req.get_headers().content_type
if not content_type or content_type:lower() ~= "application/json" then
ngx.exit(ngx.HTTP_BAD_REQUEST)
end
ngx.req.read_body()
local data = ngx.req.get_body_data()
local ok, err = api.import(ngx.var.arg_znode or "/", data)
if ok then
ngx.say("Imported")
else
ngx.say(err)
end
}
}
}
}
```
**Watch tree**
```nginx
location / {
content_by_lua_block {
local zoo = require "zoo"
local cjson = require "cjson"
local function on_event(ctx, ev)
local data = assert(zoo.watch(ev.path, ev.watcher_type, on_event, ctx))
ngx.log(ngx.INFO, "on_event: ", ev.path, ", type=", ev.watcher_type, " :", cjson.encode(data))
if ev.watcher_type == zoo.WatcherType.CHILDREN then
for _,c in ipairs(data) do
if not zoo.watcher_exists(ev.path .. "/" .. c) then
assert(zoo.watch_path(ev.path .. "/" .. c, on_event, ctx))
end
end
ctx.data[ev.path] = data
end
end
local ctx = { ["/test"] = assert(zoo.childrens("/test")) }
assert(zoo.watch_path("/test", on_event, ctx))
}
}
```
[Back to TOC](#table-of-contents)
Simple UI
========================
UI displays Zookeeper content.
Available on `http://127.0.0.1:4444`
[Back to TOC](#table-of-contents)
Configuration directives
========================
zookeeper
--------------
* **syntax**: `zookeeper `
* **default**: `none`
* **context**: `http`
Configure Zookeeper servers.
zookeeper_log_level
--------------
* **syntax**: `zookeeper_log_level `
* **default**: `error`
* **values**: `error, warn, info, debug`
* **context**: `http`
Configure Zookeeper log level.
zookeeper_recv_timeout
--------------
* **syntax**: `zookeeper_recv_timeout `
* **default**: `10000`
* **values**: `1-60000`
* **context**: `http`
Configure Zookeeper socket recv timeout.
zookeeper_node
--------------
* **syntax**: `zookeeper_node [data]`
* **default**: `none`
* **context**: `http,server,location`
Create persistent Zookeeper node.
zookeeper_ephemeral_node
--------------
* **syntax**: `zookeeper_ephemeral_node [data]`
* **default**: `none`
* **context**: `http,server,location`
Register nginx in Zookeeper ephemeral node.
zookeeper_register_port
--------------
* **syntax**: `zookeeper_register_port [data]`
* **default**: `none`
* **context**: `server`
Register nginx in Zookeeper ephemeral node with host_IPv4:port.
zookeeper_inactive_time
--------------
* **syntax**: `zookeeper_inactive_time `
* **default**: `none`
* **context**: `http`
Disconnect from zookeeper after inactive period.
[Back to TOC](#table-of-contents)
Methods
=======
connected
---------
**syntax:** `connected = zoo.connected()`
**context:** **_by_lua**
Return status of Zookeeper connection.
Returns true or false.
get
---
**syntax:** `value, stat, err = zoo.get(znode, nocache)`
**context:** **_by_lua**
Get value of the `znode` and znode information.
`stat`: { czxid, mzxid, ctime, mtime, version, cversion, aversion, ephemeralOwner, dataLength, numChildren, pzxid }
`nocache=true`: bypass cache.
Returns value on success, or nil and a string describing an error otherwise.
childrens
---------
**syntax:** `childs, err = zoo.childrens(znode, nocache)`
**context:** **_by_lua**
Get child znode's names of the `znode`.
`nocache=true`: bypass cache.
Returns table with znode's names on success, or nil and a string describing an error otherwise.
set
---
**syntax:** `result, err = zoo.set(znode, value, version)`
**context:** **_by_lua**
Set value of the `znode`. Version may be nil (no version check). `value` may be a table (converted to json on store).
Returns znode information on success, or nil and a string describing an error otherwise.
create
------
**syntax:** `result, err = zoo.create(znode, value, mode)`
**context:** **_by_lua**
Create the `znode` with initial `value`.
`mode`: flags.ZOO_EPHEMERAL, flags.ZOO_SEQUENCE
Returns new `znode` path on success, or nil and a string describing an error otherwise.
delete
------
**syntax:** `ok, err = zoo.delete(znode)`
**context:** **_by_lua**
Delete the `znode`.
Returns true on success, or false and a string describing an error otherwise.
[Back to TOC](#table-of-contents)
delete_recursive
----------------
**syntax:** `ok, err = zoo.delete_recursive(znode)`
**context:** **_by_lua**
Delete the `znode` with all childs.
Returns true on success, or false and a string describing an error otherwise.
[Back to TOC](#table-of-contents)
tree
----
**syntax:** `data, err = zoo.tree(znode, need_stat)`
**context:** **_by_lua**
Returns subtree of znode, or false and a string describing an error otherwise
watch
----------------
**syntax:** `data, err = zoo.watch(znode, watch_type, callback, ctx)`
**context:** **_by_lua**
Get value or childrens and setup wather for `znode`.
watcher_type MUST be one of `zoo.WatcherType.CHILDREN, zoo.WatcherType.DATA`.
Returns value/childrens on success, or nil and a string describing an error otherwise.
See [Synopsis](#synopsis) for details.
[Back to TOC](#table-of-contents)
watch_path
----------------
**syntax:** `tree, err = zoo.watch_path(znode, callback, ctx)`
**context:** **_by_lua**
Get full tree and setup watchers whole tree.
Return tree on success, or nil and a string describing an error otherwise.
See [Synopsis](#synopsis) for details.
[Back to TOC](#table-of-contents)
watcher_exists
----------------
**syntax:** `flag = zoo.watcher_exists(znode, watch_type)`
**context:** **_by_lua**
Check for watcher exists for `znode`.
watcher_type MUST be one of `zoo.WatcherType.CHILDREN, zoo.WatcherType.DATA` or MAY be nil.
Returns true or false.
See [Synopsis](#synopsis) for details.
[Back to TOC](#table-of-contents)
unwatch
----------------
**syntax:** `data, err = zoo.unwatch(znode, watch_type)`
**context:** **_by_lua**
Remove watcher for `znode`.
watcher_type MUST be one of `zoo.WatcherType.CHILDREN, zoo.WatcherType.DATA`.
Returns true on success, or nil and a string describing an error otherwise.
See [Synopsis](#synopsis) for details.
[Back to TOC](#table-of-contents)
Additional API
==============
`local api = require "zoo.api"`
api tree
--------
**syntax:** `r = api.tree(znode, need_stat)`
**context:** **_by_lua**
Returns subtree of znode, or false and a string describing an error otherwise
api import
----------
**syntax:** `r = api.import(root, json)`
**context:** **_by_lua**
Import znodes from json (format - api.tree). Overwrite existing values.
Returns true on success, or false and a string describing an error otherwise.