nginx 全局變量及防DDOS攻擊的簡單配置
經常需要配置Nginx ，其中有許多以 $ 開頭的變量，經常需要查閱nginx 所支持的變量。
可能是對 Ngixn資源不熟悉，干脆就直接讀源碼，分析出支持的變量。
Nginx支持的http變量實現在 ngx_http_variables.c 的 ngx_http_core_variables存儲實現：
ngx_http_core_variables
1 static ngx_http_variable_t ngx_http_core_variables[] = {
2
3 { ngx_string("http_host"), NULL, ngx_http_variable_header,
4 offsetof(ngx_http_request_t, headers_in.host), 0, 0 },
5
6 { ngx_string("http_user_agent"), NULL, ngx_http_variable_header,
7 offsetof(ngx_http_request_t, headers_in.user_agent), 0, 0 },
8
9 { ngx_string("http_referer"), NULL, ngx_http_variable_header,
10 offsetof(ngx_http_request_t, headers_in.referer), 0, 0 },
11
12 #if (NGX_HTTP_GZIP)
13 { ngx_string("http_via"), NULL, ngx_http_variable_header,
14 offsetof(ngx_http_request_t, headers_in.via), 0, 0 },
15 #endif
16
17 #if (NGX_HTTP_PROXY || NGX_HTTP_REALIP)
18 { ngx_string("http_x_forwarded_for"), NULL, ngx_http_variable_header,
19 offsetof(ngx_http_request_t, headers_in.x_forwarded_for), 0, 0 },
20 #endif
21
22 { ngx_string("http_cookie"), NULL, ngx_http_variable_headers,
23 offsetof(ngx_http_request_t, headers_in.cookies), 0, 0 },
24
25 { ngx_string("content_length"), NULL, ngx_http_variable_header,
26 offsetof(ngx_http_request_t, headers_in.content_length), 0, 0 },
27
28 { ngx_string("content_type"), NULL, ngx_http_variable_header,
29 offsetof(ngx_http_request_t, headers_in.content_type), 0, 0 },
30
31 { ngx_string("host"), NULL, ngx_http_variable_host, 0, 0, 0 },
32
33 { ngx_string("binary_remote_addr"), NULL,
34 ngx_http_variable_binary_remote_addr, 0, 0, 0 },
35
36 { ngx_string("remote_addr"), NULL, ngx_http_variable_remote_addr, 0, 0, 0 },
37
38 { ngx_string("remote_port"), NULL, ngx_http_variable_remote_port, 0, 0, 0 },
39
40 { ngx_string("server_addr"), NULL, ngx_http_variable_server_addr, 0, 0, 0 },
41
42 { ngx_string("server_port"), NULL, ngx_http_variable_server_port, 0, 0, 0 },
43
44 { ngx_string("server_protocol"), NULL, ngx_http_variable_request,
45 offsetof(ngx_http_request_t, http_protocol), 0, 0 },
46
47 { ngx_string("scheme"), NULL, ngx_http_variable_scheme, 0, 0, 0 },
48
49 { ngx_string("request_uri"), NULL, ngx_http_variable_request,
50 offsetof(ngx_http_request_t, unparsed_uri), 0, 0 },
51
52 { ngx_string("uri"), NULL, ngx_http_variable_request,
53 offsetof(ngx_http_request_t, uri),
54 NGX_HTTP_VAR_NOCACHEABLE, 0 },
55
56 { ngx_string("document_uri"), NULL, ngx_http_variable_request,
57 offsetof(ngx_http_request_t, uri),
58 NGX_HTTP_VAR_NOCACHEABLE, 0 },
59
60 { ngx_string("request"), NULL, ngx_http_variable_request_line, 0, 0, 0 },
61
62 { ngx_string("document_root"), NULL,
63 ngx_http_variable_document_root, 0, NGX_HTTP_VAR_NOCACHEABLE, 0 },
64
65 { ngx_string("realpath_root"), NULL,
66 ngx_http_variable_realpath_root, 0, NGX_HTTP_VAR_NOCACHEABLE, 0 },
67
68 { ngx_string("query_string"), NULL, ngx_http_variable_request,
69 offsetof(ngx_http_request_t, args),
70 NGX_HTTP_VAR_NOCACHEABLE, 0 },
71
72 { ngx_string("args"),
73 ngx_http_variable_request_set,
74 ngx_http_variable_request,
75 offsetof(ngx_http_request_t, args),
76 NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE, 0 },
77
78 { ngx_string("is_args"), NULL, ngx_http_variable_is_args,
79 0, NGX_HTTP_VAR_NOCACHEABLE, 0 },
80
81 { ngx_string("request_filename"), NULL,
82 ngx_http_variable_request_filename, 0,
83 NGX_HTTP_VAR_NOCACHEABLE, 0 },
84
85 { ngx_string("server_name"), NULL, ngx_http_variable_server_name, 0, 0, 0 },
86
87 { ngx_string("request_method"), NULL,
88 ngx_http_variable_request_method, 0,
89 NGX_HTTP_VAR_NOCACHEABLE, 0 },
90
91 { ngx_string("remote_user"), NULL, ngx_http_variable_remote_user, 0, 0, 0 },
92
93 { ngx_string("body_bytes_sent"), NULL, ngx_http_variable_body_bytes_sent,
94 0, 0, 0 },
95
96 { ngx_string("request_completion"), NULL,
97 ngx_http_variable_request_completion,
98 0, 0, 0 },
99
100 { ngx_string("request_body"), NULL,
101 ngx_http_variable_request_body,
102 0, 0, 0 },
103
104 { ngx_string("request_body_file"), NULL,
105 ngx_http_variable_request_body_file,
106 0, 0, 0 },
107
108 { ngx_string("sent_http_content_type"), NULL,
109 ngx_http_variable_sent_content_type, 0, 0, 0 },
110
111 { ngx_string("sent_http_content_length"), NULL,
112 ngx_http_variable_sent_content_length, 0, 0, 0 },
113
114 { ngx_string("sent_http_location"), NULL,
115 ngx_http_variable_sent_location, 0, 0, 0 },
116
117 { ngx_string("sent_http_last_modified"), NULL,
118 ngx_http_variable_sent_last_modified, 0, 0, 0 },
119
120 { ngx_string("sent_http_connection"), NULL,
121 ngx_http_variable_sent_connection, 0, 0, 0 },
122
123 { ngx_string("sent_http_keep_alive"), NULL,
124 ngx_http_variable_sent_keep_alive, 0, 0, 0 },
125
126 { ngx_string("sent_http_transfer_encoding"), NULL,
127 ngx_http_variable_sent_transfer_encoding, 0, 0, 0 },
128
129 { ngx_string("sent_http_cache_control"), NULL, ngx_http_variable_headers,
130 offsetof(ngx_http_request_t, headers_out.cache_control), 0, 0 },
131
132 { ngx_string("limit_rate"), ngx_http_variable_request_set_size,
133 ngx_http_variable_request_get_size,
134 offsetof(ngx_http_request_t, limit_rate),
135 NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOCACHEABLE, 0 },
136
137 { ngx_string("nginx_version"), NULL, ngx_http_variable_nginx_version,
138 0, 0, 0 },
139
140 { ngx_string("hostname"), NULL, ngx_http_variable_hostname,
141 0, 0, 0 },
142
143 { ngx_string("pid"), NULL, ngx_http_variable_pid,
144 0, 0, 0 },
145
146 { ngx_null_string, NULL, NULL, 0, 0, 0 }
147 };
把這些變量提取下，總結如下：
nginx防DDOS攻擊的簡單配置
nginx本身就有防DDOS攻擊這方面的模塊ngx_http_limit_req_module和ngx_http_limit_conn_module。
一、基本介紹
1.ngx_http_limit_req_module
配置格式及說明：
設置一個緩存區保存不同key的狀態，這里的狀態是指當前的過量請求數。而key是由variable指定的，是一個非空的變量，我們這里使用$binary_remote_addr，表示源IP為key值。
limit_req_zone $variable zone=name:size rate=rate;
指定要進行限制的緩存區和最大的請求到達后有多少個請求放入延遲隊列（其它的直接丟棄）。如果不希望請求
關鍵詞：nginx,DDOS攻擊
閱讀本文后您有什么感想? 已有 人給出評價!
- 1
- 1
- 1
- 1
- 1
- 1
