一、冲突的配置指令以谁为准？
1、配置块的嵌套
main
http {
upstream { … }
split_clients {…}
map {…}
geo {…}
server {
if () {…}
location {
limit_except {…}
}
location {
location {
}
}
}
server {
}
}
2、指令的Context
Syntax: log_format name [escape=default|json|none] string ...; Default: log_format combined "..."; Context: http Syntax: access_log path [format [buffer=size] [gzip[=level]] [flush=time] [if=condition]]; access_log off; Default: access_log logs/access.log combined; Context: http, server, location, if in location, limit_excep
3、值指令：存储配置项的值（可以合并）
root access_log gzip
4、动作类指令：指定行为（不可以合并）
rewrite proxy_pass
生效阶段
server_rewrite 阶段 rewrite 阶段 content 阶段
5、存储值的指令集成规则：向上覆盖
server {
listen 8080;
root /home/geek/nginx/html;
access_log logs/geek.access.log main;
location /test {
root /home/geek/nginx/test;
access_log logs/access.test.log main;
}
location /dlib {
alias dlib/;
}
location / {
}
}
子配置不存在时，直接使用父配置块；子配置存在时，直接覆盖父配置块
二、HTTP模块合并配置的实现
1、指令在哪个块下生效？
就是11个阶段的那个阶段
2、指令允许出现在那些块下？
{ ngx_string("valid_referers"),
NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
......
3、在server块内生效、从http向server合并指令：
• char *(*merge_srv_conf)(ngx_conf_t *cf, void *prev, void *conf);
任何一个nginx模块中都有一个结构体叫：ngx_module_t 这个结构体提供的所有配置指令都在
ngx_module_t ngx_http_referer_module = {
NGX_MODULE_V1,
&ngx_http_referer_module_ctx, /* module context */
ngx_http_referer_commands, /* module directives */
NGX_HTTP_MODULE, /* module type */
NULL, /* init master */
NULL, /* init module */
NULL, /* init process */
NULL, /* init thread */
NULL, /* exit thread */
NULL, /* exit process */
NULL, /* exit master */
NGX_MODULE_V1_PADDING
};
这个结构体提供的所有配置指令都在都在ngx_command_t的数组中每一个元素就是一条指令
static ngx_command_t ngx_http_referer_commands[] = {
{ ngx_string("valid_referers"),
NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
ngx_http_valid_referers,
NGX_HTTP_LOC_CONF_OFFSET,
0,
NULL },
{ ngx_string("referer_hash_max_size"),
NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_referer_conf_t, referer_hash_max_size),
NULL },
{ ngx_string("referer_hash_bucket_size"),
NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_referer_conf_t, referer_hash_bucket_size),
NULL },
ngx_null_command
};
定义了8个可回调方法
static ngx_http_module_t ngx_http_referer_module_ctx = {
ngx_http_referer_add_variables, /* preconfiguration */
NULL, /* postconfiguration */
NULL, /* create main configuration */
NULL, /* init main configuration */
NULL, /* create server configuration */
NULL, /* merge server configuration */
ngx_http_referer_create_conf, /* create location configuration */
ngx_http_referer_merge_conf /* merge location configuration */
};
4、配置缓存在内存
• char *(*merge_loc_conf)(ngx_conf_t *cf, void *prev, void *conf);
重点看合并函数
static char *
ngx_http_referer_merge_conf(ngx_conf_t *cf, void *parent, void *child)
{
ngx_http_referer_conf_t *prev = parent;
ngx_http_referer_conf_t *conf = child;
ngx_uint_t n;
ngx_hash_init_t hash;
ngx_http_server_name_t *sn;
ngx_http_core_srv_conf_t *cscf;
if (conf->keys == NULL) {
conf->hash = prev->hash;
#if (NGX_PCRE)
ngx_conf_merge_ptr_value(conf->regex, prev->regex, NULL);
ngx_conf_merge_ptr_value(conf->server_name_regex,
prev->server_name_regex, NULL);
#endif
ngx_conf_merge_value(conf->no_referer, prev->no_referer, 0);
ngx_conf_merge_value(conf->blocked_referer, prev->blocked_referer, 0);
ngx_conf_merge_uint_value(conf->referer_hash_max_size,
prev->referer_hash_max_size, 2048);
ngx_conf_merge_uint_value(conf->referer_hash_bucket_size,
prev->referer_hash_bucket_size, 64);
return NGX_CONF_OK;
}
if (conf->server_names == 1) {
cscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_core_module);
sn = cscf->server_names.elts;
for (n = 0; n < cscf->server_names.nelts; n++) {
#if (NGX_PCRE)
if (sn[n].regex) {
if (ngx_http_add_regex_server_name(cf, conf, sn[n].regex)
!= NGX_OK)
{
return NGX_CONF_ERROR;
}
continue;
}
#endif
if (ngx_http_add_referer(cf, conf->keys, &sn[n].name, NULL)
!= NGX_OK)
{
return NGX_CONF_ERROR;
}
}
}
if ((conf->no_referer == 1 || conf->blocked_referer == 1)
&& conf->keys->keys.nelts == 0
&& conf->keys->dns_wc_head.nelts == 0
&& conf->keys->dns_wc_tail.nelts == 0)
{
ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
"the "none" or "blocked" referers are specified "
"in the "valid_referers" directive "
"without any valid referer");
return NGX_CONF_ERROR;
}
ngx_conf_merge_uint_value(conf->referer_hash_max_size,
prev->referer_hash_max_size, 2048);
ngx_conf_merge_uint_value(conf->referer_hash_bucket_size,
prev->referer_hash_bucket_size, 64);
conf->referer_hash_bucket_size = ngx_align(conf->referer_hash_bucket_size,
ngx_cacheline_size);
hash.key = ngx_hash_key_lc;
hash.max_size = conf->referer_hash_max_size;
hash.bucket_size = conf->referer_hash_bucket_size;
hash.name = "referer_hash";
hash.pool = cf->pool;
三、Listen 指令
语法解析
Syntax:
listen address[:port] [default_server] [ssl] [http2 | spdy] [proxy_protocol] [setfib=number] [fastopen=number] [backlog=number] [rcvbuf=size] [sndbuf=size] [accept_filter=filter] [deferred] [bind] [ipv6only=on|off] [reuseport] [so_keepalive=on|off|[keepidle]:[keepintvl]:[keepcnt]]; listen port [default_server] [ssl] [http2 | spdy] [proxy_protocol] [setfib=number] [fastopen=number] [backlog=number] [rcvbuf=size] [sndbuf=size] [accept_filter=filter] [deferred] [bind] [ipv6only=on|off] [reuseport] [so_keepalive=on|off|[keepidle]:[keepintvl]:[keepcnt]]; listen unix:path [default_server] [ssl] [http2 | spdy] [proxy_protocol] [backlog=number] [rcvbuf=size] [sndbuf=size] [accept_filter=filter] [deferred] [bind] [so_keepalive=on|off|[keepidle]:[keepintvl]:[keepcnt]];
Default: listen *:80 | *:8000; Context: server
示例
listen unix:/var/run/nginx.sock; listen 127.0.0.1:8000; listen 127.0.0.1; listen 8000; listen *:8000; listen localhost:8000 bind; listen [::]:8000 ipv6only=on; listen [::1];
四、接收请求事件模块
1、图解过程
2、过程中的疑难点
两种内存池
分配连接内存池：connection_pool_size:512 请求内存池
如果60s没收到请求就超时：client_header_timeout: 60s
把用户的data读取到我的用户态、这样就要分配内存：client_header_buffer_size:1k；这个很大并不合适、如果超过1k会有什么变化？
五、接收请求http模块
1、图解接收过程
2、过程中的疑难点
1、请求内存池会分配多大？
基本是连接内存池的8倍、因为请求的上下文存在业务、如果分配的太小的话会不停的扩充会影响性能
2、分配大内存：
解决了什么问题：解决有一些url太长了、最大会是多大？
并不是分配32k、先分配一个8k，把刚刚的内容拷贝到我们的第一部分、剩下的7k再去接收剩下的url如果还没有接收完、按照以上迭代、最多分配32k
large_client_header_buffers:4 8k
3、什么叫表示URL?
nginx会有很多变量、这些变量它并不是复制一份、而是c语言的指针指向我们接收的请求行、所以nginx的性能才如此强大
这里的large_client_header_buffers:4 8k和解析请求是复用的也就是解析请求用了16k 那么head就只剩下16k
3、过大的请求头部
Syntax: client_header_buffer_size size; Default: client_header_buffer_size 1k; Context: http, server Syntax: large_client_header_buffers number size; Default: large_client_header_buffers 4 8k; Context: http, serve
六、正则表达式
1、元字符
2、重复
3、正则表达式【和（）】
：取消原字符的特殊含义
原始url：/admin/website/article/35/change/uploads/party/5.jpg 转换后的：/static/uploads/party/5.jpg
（）分组与取值
匹配原始url的正则表达式： /^/admin/website/article/(d+)/change/uploads/(w+)/(w+).(png|jpg|gif|jpeg|bmp)$/ rewrite^/admin/website/solution/(d+)/change/uploads/(.*).(png|jpg|gif|jpeg|bmp)$/static/uploads/$2/$3.$4 last;
4、正则表达式的验证pcre2test
安装
wget file:///C:/Users/lah/Downloads/pcre2-10.35.tar.gz tar xf pcre2-10.35.tar.gz cd pcre2-10.35 ./configure --enable-utf8 make && make install echo $?
测试验证：
[root@ceph-client ~]# pcre2test PCRE2 version 10.35 2020-05-09 re> /^/admin/website/article/(d+)/change/uploads/(w+)/(w+).(png|jpg|gif|jpeg|b mp)$/ > data> /admin/website/article/35/change/uploads/party/5.jpg 0: /admin/website/article/35/change/uploads/party/5.jpg 1: 35 2: party 3: 5 4: jpg
注意事项：
1、在nginx中使用不需要添加/但是在pcre2test中需要加
2、不能带点、所以这里的.我用了转义符号
.(png|jpg|gif|jpeg|bmp)$/