OpenResty--------核心執行階段篇

前言

前兩篇分別介紹了OpenResty核心概念和，優勢與架構等信息，進行本篇之前建議至少觀看一遍。

• OpenResty--------企業級理論實踐篇
• OpenResty--------企業級入門實踐篇

背景

之前篇章介紹了OpenResty是基於Nginx爲基礎核心的開發平臺，
本篇將繼續介紹基礎平臺(Nginx)的主要特性。

特性

執行階段

OpenResty將應用分爲４個大階段，11個小階段，如下圖所示。

• 初始化階段: master進程啓動預加載／生成worker進程預加載
• 轉發/訪問階段：url轉發，權限判斷
• 內容處理/生成階段: 內容生成
• 日誌階段: 日誌記錄

開發中常用的7階段

• set_by_lua*: 流程分支處理判斷變量初始化
• rewrite_by_lua*: 轉發、重定向、緩存等功能(例如特定請求代理到外網)
• access_by_lua*: IP 准入、接口權限等情況集中處理(例如配合 iptable 完成簡單防火牆)
• content_by_lua*: 內容生成
• header_filter_by_lua*: 響應頭部過濾處理(例如添加頭部信息)
• body_filter_by_lua*: 響應體過濾處理(例如完成應答內容統一成大寫)
• log_by_lua*: 會話完成後本地異步完成日誌記錄(日誌可以記錄在本地，還可以同步到其他機器)

測試[常用的7階段]

環境

[root@localhost ~]# cat /etc/redhat-release 
CentOS Linux release 7.4.1708 (Core) 
[root@localhost ~]# uname -r
3.10.0-693.el7.x86_64

OpenResty版本

[root@localhost ~]# /usr/local/openresty/bin/openresty -v
nginx version: openresty/1.13.6.2

創建測試項目目錄

[root@localhost ~]# mkdir -vp openresty-phase-test/{conf,logs}
mkdir: created directory ‘openresty-phase-test’
mkdir: created directory ‘openresty-phase-test/conf’
mkdir: created directory ‘openresty-phase-test/logs’

編寫配置文件

通過ngx.log輸出錯誤級別日誌至文件中

[root@localhost ~]# cat openresty-phase-test/conf/nginx.conf 
worker_processes 1; # 設置worker數量
error_log logs/error.log; # 指定錯誤日誌文件路徑
events {
    worker_connections 1024; # 單個worker進程最大允許同時建立外部連接的數量
}

http {
    server {
        listen 9999; # 設置監聽端口, 注意系統其它服務是否已佔用該端口

        location / {
            set_by_lua_block $a {
                ngx.log(ngx.ERR, "my is set_by_lua_block phase")
            }

            rewrite_by_lua_block {
                ngx.log(ngx.ERR, "my is rewrite_by_lua_block phase")
            }

            access_by_lua_block {
                ngx.log(ngx.ERR, "my is access_by_lua_block phase")
            }

            content_by_lua_block {
                ngx.log(ngx.ERR, "my is content_by_lua_block phase")
            }

            header_filter_by_lua_block {
                ngx.log(ngx.ERR, "my is header_filter_by_lua_block phase")
            }

            body_filter_by_lua_block {
                ngx.log(ngx.ERR, "my is body_filter_by_lua_block phase")
            }

            log_by_lua_block {
                ngx.log(ngx.ERR, "my is log_by_lua_block phase")
            }
        }  
    }
}

通過openresty運行應用

[root@localhost ~]# /usr/local/openresty/bin/openresty -p openresty-phase-test

查看錯誤日誌文件內容

[root@localhost ~]# cat openresty-phase-test/logs/error.log 
[root@localhost ~]#

此時錯誤日誌文件內容爲空

通過curl工具發起測試請求[本地，端口爲配置文件中的9999]

[root@localhost ~]# curl 127.0.0.1:9999                      

查看錯誤日誌文件內容

2019/08/02 05:34:22 [error] 1092#0: *1 [lua] set_by_lua:2: my is set_by_lua_block phase, client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "127.0.0.1:9999"
2019/08/02 05:34:22 [error] 1092#0: *1 [lua] rewrite_by_lua(nginx.conf:18):2: my is rewrite_by_lua_block phase, client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "127.0.0.1:9999"
2019/08/02 05:34:22 [error] 1092#0: *1 [lua] access_by_lua(nginx.conf:22):2: my is access_by_lua_block phase, client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "127.0.0.1:9999"
2019/08/02 05:34:22 [error] 1092#0: *1 [lua] content_by_lua(nginx.conf:27):2: my is content_by_lua_block phase, client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "127.0.0.1:9999"
2019/08/02 05:34:22 [error] 1092#0: *1 [lua] header_filter_by_lua:2: my is header_filter_by_lua_block phase, client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "127.0.0.1:9999"
2019/08/02 05:34:22 [error] 1092#0: *1 [lua] body_filter_by_lua:2: my is body_filter_by_lua_block phase, client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "127.0.0.1:9999"
2019/08/02 05:34:22 [error] 1092#0: *1 [lua] log_by_lua(nginx.conf:39):2: my is log_by_lua_block phase while logging request, client: 127.0.0.1, server: , request: "GET / HTTP/1.1", host: "127.0.0.1:9999"

可以看到安排階段順序進行輸出