Nginx(六):配置解析之location解析
共 69905字,需浏览 140分钟
·
2021-01-24 04:28
nginx成为非常流行的代理服务软件,最根本的原因也许是在于其强悍性能。但还有一些必要的条件,比如功能的完整,配置的易用,能够解决各种各样的实际需求问题,这些是一个好的软件的必备特性。
那么,今天我们就来看看nginx配置的部分原则和解析原理吧。我们只做location部分的细节解析,但其他配置道理基本相通,推一及二即可。
1:nginx配置的基本原则
nginx是支持高度配置化的,那么也许就会涉及许多部分的配置,要如何协调好这些配置,是个问题。比如是否将配置定义一个个独立的文件,或者其他。
然而,nginx使用一个统一的配置文件,管理起了所有的配置工作。即 nginx.conf, 其默认位置是 $NGINX_HOME/nginx.conf, 在这个主配置文件中,又可以包含其他任意多的配置文件,从而达到统一管理的作用。
其默认配置nginx.conf如下:
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
server {
listen 80;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root html;
index index.html index.htm;
}
#error_page 404 /404.html;
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ \.php$ {
# proxy_pass http://127.0.0.1;
#}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ \.php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /\.ht {
# deny all;
#}
}
# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8000;
# listen somename:8080;
# server_name somename alias another.alias;
# location / {
# root html;
# index index.html index.htm;
# }
#}
# HTTPS server
#
#server {
# listen 443 ssl;
# server_name localhost;
# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;
# ssl_session_cache shared:SSL:1m;
# ssl_session_timeout 5m;
# ssl_ciphers HIGH:!aNULL:!MD5;
# ssl_prefer_server_ciphers on;
# location / {
# root html;
# index index.html index.htm;
# }
#}
}
这很明显不是什么标准语言语法,但其同样遵从一定的准则,从而让用户更易于理解配置。如:
1. 每一个细配置项,都使用一个';'作为结束标识;
2. '#' 代表该行被注释(这几乎是linux默认标准);
3. 使用'{}'表示一个配置块,'{}'中代表其子项配置;
4. 使用include可以包含其他文件的配置,相当于将其中的配置项copy到当前位置,该包含路径可以是相对路径也可以是绝对路径;
因此,基本上,你只要按照这个标准来做配置,至少语法 是不会有误了。但是,具体应该如何配置呢?实际上这要依赖于某类操作的具体实现,比如 location 的 配置, user 的配置,都是有各自的含义的。如果想要具体了解各细节配置,则必须要查询官网的配置定义了。请参考: https://docs.nginx.com/nginx/admin-guide/basic-functionality/managing-configuration-files/
总体上来说,nginx有几个顶级配置:
events – 连接类的配置,比如最大连接数配置
http – 重头戏,http模块配置,所有的代理服务http服务都在其子配置下
mail – 邮件配置
stream – TCP、UDP 底层通信协议配置,功能与http模块相仿
一般地我们接接触最多的应该就是http配置了,至于其他功能,没有实践就没有发言权,略去不说。
2. location的配置用例
location的本义是用于定位一个http请求匹配情况,用于确定某个路径的请求应该如何做转换处理。它是属于 http 模块下的 server 模块下的一个选项配置。即 nginx -> http -> server -> location {..} 是其配置体现。它拥有相当多的配置项,因为做反向代理或其他服务器时,往往都可以通过这个配置,将功能完成。
如下几个配置项,可供参考:
http {
upstream backend {
ip_hash;
server backend1.example.com weight=5;
server backend2.example.com;
server 192.0.0.1 backup;
}
server {
root /www/data;
# 路径相等处理,优先级最高
location = / {
#...
}
# 根路径配置,优先级最低
location / {
root /data/www;
}
# 带前缀的配置,优先级其次
location /images/ {
root /data;
}
# 正则匹配的配置,优先级较高
location ~ \.(gif|jpg|png)$ {
root /data/images;
}
# 正则取反配置
location ^~ \.(php)$ {
root /data/other;
}
# 反向代理的配置,将请求转换给后端服务
# 如果backend是一个 upstream 配置,则做为一个负载均衡器使用
location /api1 {
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_pass http://backend;
}
location /api2 {
proxy_pass http://www.abc.com;
}
# 路径重写
location /users/ {
rewrite ^/users/(.*)$ /show?user=$1 break;
}
# 带状态码的返回配置
location /wrong/url {
return 404;
open_file_cache_errors off;
}
location /permanently/moved/url {
return 301 http://www.example.com/moved/here;
}
# 响应内容替换
location / {
sub_filter 'href="http://127.0.0.1:8080/' 'href="https://$host/';
sub_filter 'img src="http://127.0.0.1:8080/' 'img src="https://$host/';
sub_filter_once on;
}
}
}
更多内容可查阅官网: https://docs.nginx.com/nginx/admin-guide/web-server/web-server/
总体上来说,location提供了可以配置如何查找本地文件,以及可以配置如何转发请求到其他服务器的方式。其中,还有很多附加的设置各种需求变量的实现,以辅助我们实现一些正常请求提供的内容。配置比较多,到真正使用时,按需配置即可。一般也是一次配置,永久使用,不会太费事。
3. location配置的解析
nginx有自己的一套配置方法,那么这些配置好了的语句,如何应用到具体的服务上呢?自然是需要先进行解析,然后放置到对应的内存空间变量中,然后在需要的时候进行读取判定,以及转换了。大体思路如此,但如何解析配置却并非易事。因为我们的配置是无数现有配置的任意组合,如何有效的放置到可理解的位置,应该需要单独的数据结构设计,以及解析步骤。实际上,这也相当于是一个简单的编译器或解析器,它需要将文本解析为认识的东西。
下面我们就一起来看看nginx都是如何解析这些配置的吧!(这自然是在启动时完成的工作)
// 首先,nginx会解析启动行命令,这里面可以指定配置文件
// core/nginx.c
static ngx_int_t
ngx_get_options(int argc, char *const *argv)
{
u_char *p;
ngx_int_t i;
for (i = 1; i < argc; i++) {
p = (u_char *) argv[i];
if (*p++ != '-') {
ngx_log_stderr(0, "invalid option: \"%s\"", argv[i]);
return NGX_ERROR;
}
while (*p) {
switch (*p++) {
case '?':
case 'h':
ngx_show_version = 1;
ngx_show_help = 1;
break;
case 'v':
ngx_show_version = 1;
break;
case 'V':
ngx_show_version = 1;
ngx_show_configure = 1;
break;
// -t 测试配置文件有效性
case 't':
ngx_test_config = 1;
break;
case 'T':
ngx_test_config = 1;
ngx_dump_config = 1;
break;
case 'q':
ngx_quiet_mode = 1;
break;
case 'p':
if (*p) {
ngx_prefix = p;
goto next;
}
if (argv[++i]) {
ngx_prefix = (u_char *) argv[i];
goto next;
}
ngx_log_stderr(0, "option \"-p\" requires directory name");
return NGX_ERROR;
// -c nginx.conf 指定nginx配置文件路径
case 'c':
if (*p) {
ngx_conf_file = p;
goto next;
}
if (argv[++i]) {
ngx_conf_file = (u_char *) argv[i];
goto next;
}
ngx_log_stderr(0, "option \"-c\" requires file name");
return NGX_ERROR;
case 'g':
if (*p) {
ngx_conf_params = p;
goto next;
}
if (argv[++i]) {
ngx_conf_params = (u_char *) argv[i];
goto next;
}
ngx_log_stderr(0, "option \"-g\" requires parameter");
return NGX_ERROR;
// -s (stop|quit|reopen|reload) 向现有运行的nginx进程发起控制命令
case 's':
// 紧贴式给出命令: -sstop, -sreload
if (*p) {
ngx_signal = (char *) p;
} else if (argv[++i]) {
ngx_signal = argv[i];
} else {
ngx_log_stderr(0, "option \"-s\" requires parameter");
return NGX_ERROR;
}
if (ngx_strcmp(ngx_signal, "stop") == 0
|| ngx_strcmp(ngx_signal, "quit") == 0
|| ngx_strcmp(ngx_signal, "reopen") == 0
|| ngx_strcmp(ngx_signal, "reload") == 0)
{
ngx_process = NGX_PROCESS_SIGNALLER;
goto next;
}
ngx_log_stderr(0, "invalid option: \"-s %s\"", ngx_signal);
return NGX_ERROR;
default:
ngx_log_stderr(0, "invalid option: \"%c\"", *(p - 1));
return NGX_ERROR;
}
}
next:
continue;
}
return NGX_OK;
}
以上,是对命令行参数的简单解析,解析出来的变量放入到各全局变量中:ngx_show_version|ngx_show_help|ngx_show_configure|ngx_test_config|ngx_dump_config|ngx_quiet_mode|ngx_prefix|ngx_conf_file|ngx_conf_params|ngx_signal.
以上,最重要的是两个参数:-c -s, 用于指定配置文件和操作现有nginx进程。当然,对于配置解析,自然最重要的是 -c 命令了。但对于一些没有指定的配置值,则使用系统的默认值。其处理如下:
// core/nginx.c
static ngx_int_t
ngx_process_options(ngx_cycle_t *cycle)
{
u_char *p;
size_t len;
if (ngx_prefix) {
len = ngx_strlen(ngx_prefix);
p = ngx_prefix;
if (len && !ngx_path_separator(p[len - 1])) {
p = ngx_pnalloc(cycle->pool, len + 1);
if (p == NULL) {
return NGX_ERROR;
}
ngx_memcpy(p, ngx_prefix, len);
p[len++] = '/';
}
cycle->conf_prefix.len = len;
cycle->conf_prefix.data = p;
cycle->prefix.len = len;
cycle->prefix.data = p;
} else {
#ifndef NGX_PREFIX
p = ngx_pnalloc(cycle->pool, NGX_MAX_PATH);
if (p == NULL) {
return NGX_ERROR;
}
if (ngx_getcwd(p, NGX_MAX_PATH) == 0) {
ngx_log_stderr(ngx_errno, "[emerg]: " ngx_getcwd_n " failed");
return NGX_ERROR;
}
len = ngx_strlen(p);
p[len++] = '/';
cycle->conf_prefix.len = len;
cycle->conf_prefix.data = p;
cycle->prefix.len = len;
cycle->prefix.data = p;
#else
#ifdef NGX_CONF_PREFIX
// 默认路径前缀: conf/
ngx_str_set(&cycle->conf_prefix, NGX_CONF_PREFIX);
#else
ngx_str_set(&cycle->conf_prefix, NGX_PREFIX);
#endif
ngx_str_set(&cycle->prefix, NGX_PREFIX);
#endif
}
if (ngx_conf_file) {
cycle->conf_file.len = ngx_strlen(ngx_conf_file);
cycle->conf_file.data = ngx_conf_file;
} else {
// 默认配置文件: conf/nginx.conf
ngx_str_set(&cycle->conf_file, NGX_CONF_PATH);
}
if (ngx_conf_full_name(cycle, &cycle->conf_file, 0) != NGX_OK) {
return NGX_ERROR;
}
for (p = cycle->conf_file.data + cycle->conf_file.len - 1;
p > cycle->conf_file.data;
p--)
{
if (ngx_path_separator(*p)) {
cycle->conf_prefix.len = p - cycle->conf_file.data + 1;
cycle->conf_prefix.data = cycle->conf_file.data;
break;
}
}
if (ngx_conf_params) {
cycle->conf_param.len = ngx_strlen(ngx_conf_params);
cycle->conf_param.data = ngx_conf_params;
}
if (ngx_test_config) {
cycle->log->log_level = NGX_LOG_INFO;
}
return NGX_OK;
}
真正的配置文件解析是在初始化cycle的时候处理实现的:
// core/ngx_cycle.c
ngx_cycle_t *
ngx_init_cycle(ngx_cycle_t *old_cycle)
{
void *rv;
char **senv;
ngx_uint_t i, n;
ngx_log_t *log;
ngx_time_t *tp;
ngx_conf_t conf;
ngx_pool_t *pool;
ngx_cycle_t *cycle, **old;
ngx_shm_zone_t *shm_zone, *oshm_zone;
ngx_list_part_t *part, *opart;
ngx_open_file_t *file;
ngx_listening_t *ls, *nls;
ngx_core_conf_t *ccf, *old_ccf;
ngx_core_module_t *module;
char hostname[NGX_MAXHOSTNAMELEN];
ngx_timezone_update();
/* force localtime update with a new timezone */
tp = ngx_timeofday();
tp->sec = 0;
ngx_time_update();
log = old_cycle->log;
pool = ngx_create_pool(NGX_CYCLE_POOL_SIZE, log);
if (pool == NULL) {
return NULL;
}
pool->log = log;
cycle = ngx_pcalloc(pool, sizeof(ngx_cycle_t));
if (cycle == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
cycle->pool = pool;
cycle->log = log;
cycle->old_cycle = old_cycle;
cycle->conf_prefix.len = old_cycle->conf_prefix.len;
cycle->conf_prefix.data = ngx_pstrdup(pool, &old_cycle->conf_prefix);
if (cycle->conf_prefix.data == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
cycle->prefix.len = old_cycle->prefix.len;
cycle->prefix.data = ngx_pstrdup(pool, &old_cycle->prefix);
if (cycle->prefix.data == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
cycle->conf_file.len = old_cycle->conf_file.len;
cycle->conf_file.data = ngx_pnalloc(pool, old_cycle->conf_file.len + 1);
if (cycle->conf_file.data == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
ngx_cpystrn(cycle->conf_file.data, old_cycle->conf_file.data,
old_cycle->conf_file.len + 1);
cycle->conf_param.len = old_cycle->conf_param.len;
cycle->conf_param.data = ngx_pstrdup(pool, &old_cycle->conf_param);
if (cycle->conf_param.data == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
n = old_cycle->paths.nelts ? old_cycle->paths.nelts : 10;
if (ngx_array_init(&cycle->paths, pool, n, sizeof(ngx_path_t *))
!= NGX_OK)
{
ngx_destroy_pool(pool);
return NULL;
}
ngx_memzero(cycle->paths.elts, n * sizeof(ngx_path_t *));
if (ngx_array_init(&cycle->config_dump, pool, 1, sizeof(ngx_conf_dump_t))
!= NGX_OK)
{
ngx_destroy_pool(pool);
return NULL;
}
// 使用红黑树存放配置信息
ngx_rbtree_init(&cycle->config_dump_rbtree, &cycle->config_dump_sentinel,
ngx_str_rbtree_insert_value);
// 默认使用 20 个端口服务
if (old_cycle->open_files.part.nelts) {
n = old_cycle->open_files.part.nelts;
for (part = old_cycle->open_files.part.next; part; part = part->next) {
n += part->nelts;
}
} else {
n = 20;
}
// 每个监听端口使用一个 open_files 表示
if (ngx_list_init(&cycle->open_files, pool, n, sizeof(ngx_open_file_t))
!= NGX_OK)
{
ngx_destroy_pool(pool);
return NULL;
}
if (old_cycle->shared_memory.part.nelts) {
n = old_cycle->shared_memory.part.nelts;
for (part = old_cycle->shared_memory.part.next; part; part = part->next)
{
n += part->nelts;
}
} else {
n = 1;
}
if (ngx_list_init(&cycle->shared_memory, pool, n, sizeof(ngx_shm_zone_t))
!= NGX_OK)
{
ngx_destroy_pool(pool);
return NULL;
}
n = old_cycle->listening.nelts ? old_cycle->listening.nelts : 10;
if (ngx_array_init(&cycle->listening, pool, n, sizeof(ngx_listening_t))
!= NGX_OK)
{
ngx_destroy_pool(pool);
return NULL;
}
ngx_memzero(cycle->listening.elts, n * sizeof(ngx_listening_t));
ngx_queue_init(&cycle->reusable_connections_queue);
cycle->conf_ctx = ngx_pcalloc(pool, ngx_max_module * sizeof(void *));
if (cycle->conf_ctx == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
// 获取当前机器的hostname
if (gethostname(hostname, NGX_MAXHOSTNAMELEN) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "gethostname() failed");
ngx_destroy_pool(pool);
return NULL;
}
/* on Linux gethostname() silently truncates name that does not fit */
hostname[NGX_MAXHOSTNAMELEN - 1] = '\0';
cycle->hostname.len = ngx_strlen(hostname);
cycle->hostname.data = ngx_pnalloc(pool, cycle->hostname.len);
if (cycle->hostname.data == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
ngx_strlow(cycle->hostname.data, (u_char *) hostname, cycle->hostname.len);
// 创建module内存空间
if (ngx_cycle_modules(cycle) != NGX_OK) {
ngx_destroy_pool(pool);
return NULL;
}
// 让各模块依次进行配置
for (i = 0; cycle->modules[i]; i++) {
// NGINX_CORE_MODULE 可以进行配置文件处理
// 即几套顶级模块, http,events,mail,...
if (cycle->modules[i]->type != NGX_CORE_MODULE) {
continue;
}
module = cycle->modules[i]->ctx;
// 调用各模块的 create_conf 实现配置加载
// 其中,以为的http模块会进行解析,其实却没有
if (module->create_conf) {
rv = module->create_conf(cycle);
if (rv == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
cycle->conf_ctx[cycle->modules[i]->index] = rv;
}
}
senv = environ;
ngx_memzero(&conf, sizeof(ngx_conf_t));
/* STUB: init array ? */
conf.args = ngx_array_create(pool, 10, sizeof(ngx_str_t));
if (conf.args == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
conf.temp_pool = ngx_create_pool(NGX_CYCLE_POOL_SIZE, log);
if (conf.temp_pool == NULL) {
ngx_destroy_pool(pool);
return NULL;
}
conf.ctx = cycle->conf_ctx;
conf.cycle = cycle;
conf.pool = pool;
conf.log = log;
conf.module_type = NGX_CORE_MODULE;
conf.cmd_type = NGX_MAIN_CONF;
#if 0
log->log_level = NGX_LOG_DEBUG_ALL;
#endif
if (ngx_conf_param(&conf) != NGX_CONF_OK) {
environ = senv;
ngx_destroy_cycle_pools(&conf);
return NULL;
}
if (ngx_conf_parse(&conf, &cycle->conf_file) != NGX_CONF_OK) {
environ = senv;
ngx_destroy_cycle_pools(&conf);
return NULL;
}
if (ngx_test_config && !ngx_quiet_mode) {
ngx_log_stderr(0, "the configuration file %s syntax is ok",
cycle->conf_file.data);
}
for (i = 0; cycle->modules[i]; i++) {
if (cycle->modules[i]->type != NGX_CORE_MODULE) {
continue;
}
module = cycle->modules[i]->ctx;
if (module->init_conf) {
if (module->init_conf(cycle,
cycle->conf_ctx[cycle->modules[i]->index])
== NGX_CONF_ERROR)
{
environ = senv;
ngx_destroy_cycle_pools(&conf);
return NULL;
}
}
}
if (ngx_process == NGX_PROCESS_SIGNALLER) {
return cycle;
}
ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
if (ngx_test_config) {
if (ngx_create_pidfile(&ccf->pid, log) != NGX_OK) {
goto failed;
}
} else if (!ngx_is_init_cycle(old_cycle)) {
/*
* we do not create the pid file in the first ngx_init_cycle() call
* because we need to write the demonized process pid
*/
old_ccf = (ngx_core_conf_t *) ngx_get_conf(old_cycle->conf_ctx,
ngx_core_module);
if (ccf->pid.len != old_ccf->pid.len
|| ngx_strcmp(ccf->pid.data, old_ccf->pid.data) != 0)
{
/* new pid file name */
if (ngx_create_pidfile(&ccf->pid, log) != NGX_OK) {
goto failed;
}
ngx_delete_pidfile(old_cycle);
}
}
if (ngx_test_lockfile(cycle->lock_file.data, log) != NGX_OK) {
goto failed;
}
if (ngx_create_paths(cycle, ccf->user) != NGX_OK) {
goto failed;
}
if (ngx_log_open_default(cycle) != NGX_OK) {
goto failed;
}
/* open the new files */
part = &cycle->open_files.part;
file = part->elts;
for (i = 0; /* void */ ; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
file = part->elts;
i = 0;
}
if (file[i].name.len == 0) {
continue;
}
file[i].fd = ngx_open_file(file[i].name.data,
NGX_FILE_APPEND,
NGX_FILE_CREATE_OR_OPEN,
NGX_FILE_DEFAULT_ACCESS);
ngx_log_debug3(NGX_LOG_DEBUG_CORE, log, 0,
"log: %p %d \"%s\"",
&file[i], file[i].fd, file[i].name.data);
if (file[i].fd == NGX_INVALID_FILE) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
ngx_open_file_n " \"%s\" failed",
file[i].name.data);
goto failed;
}
#if !(NGX_WIN32)
if (fcntl(file[i].fd, F_SETFD, FD_CLOEXEC) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
"fcntl(FD_CLOEXEC) \"%s\" failed",
file[i].name.data);
goto failed;
}
#endif
}
cycle->log = &cycle->new_log;
pool->log = &cycle->new_log;
/* create shared memory */
part = &cycle->shared_memory.part;
shm_zone = part->elts;
for (i = 0; /* void */ ; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
shm_zone = part->elts;
i = 0;
}
if (shm_zone[i].shm.size == 0) {
ngx_log_error(NGX_LOG_EMERG, log, 0,
"zero size shared memory zone \"%V\"",
&shm_zone[i].shm.name);
goto failed;
}
shm_zone[i].shm.log = cycle->log;
opart = &old_cycle->shared_memory.part;
oshm_zone = opart->elts;
for (n = 0; /* void */ ; n++) {
if (n >= opart->nelts) {
if (opart->next == NULL) {
break;
}
opart = opart->next;
oshm_zone = opart->elts;
n = 0;
}
if (shm_zone[i].shm.name.len != oshm_zone[n].shm.name.len) {
continue;
}
if (ngx_strncmp(shm_zone[i].shm.name.data,
oshm_zone[n].shm.name.data,
shm_zone[i].shm.name.len)
!= 0)
{
continue;
}
if (shm_zone[i].tag == oshm_zone[n].tag
&& shm_zone[i].shm.size == oshm_zone[n].shm.size
&& !shm_zone[i].noreuse)
{
shm_zone[i].shm.addr = oshm_zone[n].shm.addr;
#if (NGX_WIN32)
shm_zone[i].shm.handle = oshm_zone[n].shm.handle;
#endif
if (shm_zone[i].init(&shm_zone[i], oshm_zone[n].data)
!= NGX_OK)
{
goto failed;
}
goto shm_zone_found;
}
break;
}
if (ngx_shm_alloc(&shm_zone[i].shm) != NGX_OK) {
goto failed;
}
if (ngx_init_zone_pool(cycle, &shm_zone[i]) != NGX_OK) {
goto failed;
}
if (shm_zone[i].init(&shm_zone[i], NULL) != NGX_OK) {
goto failed;
}
shm_zone_found:
continue;
}
/* handle the listening sockets */
if (old_cycle->listening.nelts) {
ls = old_cycle->listening.elts;
for (i = 0; i < old_cycle->listening.nelts; i++) {
ls[i].remain = 0;
}
nls = cycle->listening.elts;
for (n = 0; n < cycle->listening.nelts; n++) {
for (i = 0; i < old_cycle->listening.nelts; i++) {
if (ls[i].ignore) {
continue;
}
if (ls[i].remain) {
continue;
}
if (ls[i].type != nls[n].type) {
continue;
}
if (ngx_cmp_sockaddr(nls[n].sockaddr, nls[n].socklen,
ls[i].sockaddr, ls[i].socklen, 1)
== NGX_OK)
{
nls[n].fd = ls[i].fd;
nls[n].inherited = ls[i].inherited;
nls[n].previous = &ls[i];
ls[i].remain = 1;
if (ls[i].backlog != nls[n].backlog) {
nls[n].listen = 1;
}
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
/*
* FreeBSD, except the most recent versions,
* could not remove accept filter
*/
nls[n].deferred_accept = ls[i].deferred_accept;
if (ls[i].accept_filter && nls[n].accept_filter) {
if (ngx_strcmp(ls[i].accept_filter,
nls[n].accept_filter)
!= 0)
{
nls[n].delete_deferred = 1;
nls[n].add_deferred = 1;
}
} else if (ls[i].accept_filter) {
nls[n].delete_deferred = 1;
} else if (nls[n].accept_filter) {
nls[n].add_deferred = 1;
}
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
if (ls[i].deferred_accept && !nls[n].deferred_accept) {
nls[n].delete_deferred = 1;
} else if (ls[i].deferred_accept != nls[n].deferred_accept)
{
nls[n].add_deferred = 1;
}
#endif
#if (NGX_HAVE_REUSEPORT)
if (nls[n].reuseport && !ls[i].reuseport) {
nls[n].add_reuseport = 1;
}
#endif
break;
}
}
if (nls[n].fd == (ngx_socket_t) -1) {
nls[n].open = 1;
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
if (nls[n].accept_filter) {
nls[n].add_deferred = 1;
}
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
if (nls[n].deferred_accept) {
nls[n].add_deferred = 1;
}
#endif
}
}
} else {
ls = cycle->listening.elts;
for (i = 0; i < cycle->listening.nelts; i++) {
ls[i].open = 1;
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
if (ls[i].accept_filter) {
ls[i].add_deferred = 1;
}
#endif
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
if (ls[i].deferred_accept) {
ls[i].add_deferred = 1;
}
#endif
}
}
if (ngx_open_listening_sockets(cycle) != NGX_OK) {
goto failed;
}
if (!ngx_test_config) {
ngx_configure_listening_sockets(cycle);
}
/* commit the new cycle configuration */
if (!ngx_use_stderr) {
(void) ngx_log_redirect_stderr(cycle);
}
pool->log = cycle->log;
if (ngx_init_modules(cycle) != NGX_OK) {
/* fatal */
exit(1);
}
/* close and delete stuff that lefts from an old cycle */
/* free the unnecessary shared memory */
opart = &old_cycle->shared_memory.part;
oshm_zone = opart->elts;
for (i = 0; /* void */ ; i++) {
if (i >= opart->nelts) {
if (opart->next == NULL) {
goto old_shm_zone_done;
}
opart = opart->next;
oshm_zone = opart->elts;
i = 0;
}
part = &cycle->shared_memory.part;
shm_zone = part->elts;
for (n = 0; /* void */ ; n++) {
if (n >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
shm_zone = part->elts;
n = 0;
}
if (oshm_zone[i].shm.name.len != shm_zone[n].shm.name.len) {
continue;
}
if (ngx_strncmp(oshm_zone[i].shm.name.data,
shm_zone[n].shm.name.data,
oshm_zone[i].shm.name.len)
!= 0)
{
continue;
}
if (oshm_zone[i].tag == shm_zone[n].tag
&& oshm_zone[i].shm.size == shm_zone[n].shm.size
&& !oshm_zone[i].noreuse)
{
goto live_shm_zone;
}
break;
}
ngx_shm_free(&oshm_zone[i].shm);
live_shm_zone:
continue;
}
old_shm_zone_done:
/* close the unnecessary listening sockets */
ls = old_cycle->listening.elts;
for (i = 0; i < old_cycle->listening.nelts; i++) {
if (ls[i].remain || ls[i].fd == (ngx_socket_t) -1) {
continue;
}
if (ngx_close_socket(ls[i].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_close_socket_n " listening socket on %V failed",
&ls[i].addr_text);
}
#if (NGX_HAVE_UNIX_DOMAIN)
if (ls[i].sockaddr->sa_family == AF_UNIX) {
u_char *name;
name = ls[i].addr_text.data + sizeof("unix:") - 1;
ngx_log_error(NGX_LOG_WARN, cycle->log, 0,
"deleting socket %s", name);
if (ngx_delete_file(name) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
ngx_delete_file_n " %s failed", name);
}
}
#endif
}
/* close the unnecessary open files */
part = &old_cycle->open_files.part;
file = part->elts;
for (i = 0; /* void */ ; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
file = part->elts;
i = 0;
}
if (file[i].fd == NGX_INVALID_FILE || file[i].fd == ngx_stderr) {
continue;
}
if (ngx_close_file(file[i].fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
ngx_close_file_n " \"%s\" failed",
file[i].name.data);
}
}
ngx_destroy_pool(conf.temp_pool);
if (ngx_process == NGX_PROCESS_MASTER || ngx_is_init_cycle(old_cycle)) {
ngx_destroy_pool(old_cycle->pool);
cycle->old_cycle = NULL;
return cycle;
}
if (ngx_temp_pool == NULL) {
ngx_temp_pool = ngx_create_pool(128, cycle->log);
if (ngx_temp_pool == NULL) {
ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
"could not create ngx_temp_pool");
exit(1);
}
n = 10;
if (ngx_array_init(&ngx_old_cycles, ngx_temp_pool, n,
sizeof(ngx_cycle_t *))
!= NGX_OK)
{
exit(1);
}
ngx_memzero(ngx_old_cycles.elts, n * sizeof(ngx_cycle_t *));
ngx_cleaner_event.handler = ngx_clean_old_cycles;
ngx_cleaner_event.log = cycle->log;
ngx_cleaner_event.data = &dumb;
dumb.fd = (ngx_socket_t) -1;
}
ngx_temp_pool->log = cycle->log;
old = ngx_array_push(&ngx_old_cycles);
if (old == NULL) {
exit(1);
}
*old = old_cycle;
if (!ngx_cleaner_event.timer_set) {
ngx_add_timer(&ngx_cleaner_event, 30000);
ngx_cleaner_event.timer_set = 1;
}
return cycle;
failed:
if (!ngx_is_init_cycle(old_cycle)) {
old_ccf = (ngx_core_conf_t *) ngx_get_conf(old_cycle->conf_ctx,
ngx_core_module);
if (old_ccf->environment) {
environ = old_ccf->environment;
}
}
/* rollback the new cycle configuration */
part = &cycle->open_files.part;
file = part->elts;
for (i = 0; /* void */ ; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
file = part->elts;
i = 0;
}
if (file[i].fd == NGX_INVALID_FILE || file[i].fd == ngx_stderr) {
continue;
}
if (ngx_close_file(file[i].fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
ngx_close_file_n " \"%s\" failed",
file[i].name.data);
}
}
/* free the newly created shared memory */
part = &cycle->shared_memory.part;
shm_zone = part->elts;
for (i = 0; /* void */ ; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
shm_zone = part->elts;
i = 0;
}
if (shm_zone[i].shm.addr == NULL) {
continue;
}
opart = &old_cycle->shared_memory.part;
oshm_zone = opart->elts;
for (n = 0; /* void */ ; n++) {
if (n >= opart->nelts) {
if (opart->next == NULL) {
break;
}
opart = opart->next;
oshm_zone = opart->elts;
n = 0;
}
if (shm_zone[i].shm.name.len != oshm_zone[n].shm.name.len) {
continue;
}
if (ngx_strncmp(shm_zone[i].shm.name.data,
oshm_zone[n].shm.name.data,
shm_zone[i].shm.name.len)
!= 0)
{
continue;
}
if (shm_zone[i].tag == oshm_zone[n].tag
&& shm_zone[i].shm.size == oshm_zone[n].shm.size
&& !shm_zone[i].noreuse)
{
goto old_shm_zone_found;
}
break;
}
ngx_shm_free(&shm_zone[i].shm);
old_shm_zone_found:
continue;
}
if (ngx_test_config) {
ngx_destroy_cycle_pools(&conf);
return NULL;
}
ls = cycle->listening.elts;
for (i = 0; i < cycle->listening.nelts; i++) {
if (ls[i].fd == (ngx_socket_t) -1 || !ls[i].open) {
continue;
}
if (ngx_close_socket(ls[i].fd) == -1) {
ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
ngx_close_socket_n " %V failed",
&ls[i].addr_text);
}
}
ngx_destroy_cycle_pools(&conf);
return NULL;
}
nginx中设置了几个初始化的点,create_conf, init_conf, 供各模块实现各自的解析逻辑,以及使用一个全局的解析 ngx_conf_parse() 实现文件解析。
那么 http 作为独立的模块,其是否参与配置解析呢?我们看下其模块的配置即可:
// http 模块的配置简略
// http/ngx_http.c
static ngx_core_module_t ngx_http_module_ctx = {
ngx_string("http"),
// 不做 create_conf 处理
NULL,
NULL
};
ngx_module_t ngx_http_module = {
NGX_MODULE_V1,
&ngx_http_module_ctx, /* module context */
ngx_http_commands, /* module directives */
NGX_CORE_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
};
真正的解析工作在 ngx_conf_file.c 文件中进行, 有ngx_conf_param(), ngx_conf_parse() 完成具体的解析。
// core/ngx_conf_file.c
char *
ngx_conf_param(ngx_conf_t *cf)
{
char *rv;
ngx_str_t *param;
ngx_buf_t b;
ngx_conf_file_t conf_file;
param = &cf->cycle->conf_param;
if (param->len == 0) {
return NGX_CONF_OK;
}
ngx_memzero(&conf_file, sizeof(ngx_conf_file_t));
ngx_memzero(&b, sizeof(ngx_buf_t));
b.start = param->data;
b.pos = param->data;
b.last = param->data + param->len;
b.end = b.last;
b.temporary = 1;
conf_file.file.fd = NGX_INVALID_FILE;
conf_file.file.name.data = NULL;
conf_file.line = 0;
cf->conf_file = &conf_file;
cf->conf_file->buffer = &b;
// 解析param信息,不解析配置文件
rv = ngx_conf_parse(cf, NULL);
cf->conf_file = NULL;
return rv;
}
char *
ngx_conf_parse(ngx_conf_t *cf, ngx_str_t *filename)
{
char *rv;
ngx_fd_t fd;
ngx_int_t rc;
ngx_buf_t buf;
ngx_conf_file_t *prev, conf_file;
enum {
parse_file = 0,
parse_block,
parse_param
} type;
#if (NGX_SUPPRESS_WARN)
fd = NGX_INVALID_FILE;
prev = NULL;
#endif
// 如果给定配置文件,则解析
if (filename) {
/* open configuration file */
// 打开配置文件
fd = ngx_open_file(filename->data, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);
if (fd == NGX_INVALID_FILE) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
ngx_open_file_n " \"%s\" failed",
filename->data);
return NGX_CONF_ERROR;
}
prev = cf->conf_file;
cf->conf_file = &conf_file;
if (ngx_fd_info(fd, &cf->conf_file->file.info) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_EMERG, cf->log, ngx_errno,
ngx_fd_info_n " \"%s\" failed", filename->data);
}
cf->conf_file->buffer = &buf;
// NGX_CONF_BUFFER=1024
buf.start = ngx_alloc(NGX_CONF_BUFFER, cf->log);
if (buf.start == NULL) {
goto failed;
}
buf.pos = buf.start;
buf.last = buf.start;
buf.end = buf.last + NGX_CONF_BUFFER;
buf.temporary = 1; // 初始化配置文件信息
cf->conf_file->file.fd = fd;
cf->conf_file->file.name.len = filename->len;
cf->conf_file->file.name.data = filename->data;
cf->conf_file->file.offset = 0;
cf->conf_file->file.log = cf->log;
cf->conf_file->line = 1;
type = parse_file;
if (ngx_dump_config
#if (NGX_DEBUG)
|| 1
#endif
)
{
if (ngx_conf_add_dump(cf, filename) != NGX_OK) {
goto failed;
}
} else {
cf->conf_file->dump = NULL;
}
} else if (cf->conf_file->file.fd != NGX_INVALID_FILE) {
type = parse_block;
} else {
type = parse_param;
}
// 此处实现真正的解析操作
for ( ;; ) {
// 重要1: 读取出一个个地token信息, 以pos, start等变量做标识起始
rc = ngx_conf_read_token(cf);
/*
* ngx_conf_read_token() may return
*
* NGX_ERROR there is error
* NGX_OK the token terminated by ";" was found
* NGX_CONF_BLOCK_START the token terminated by "{" was found
* NGX_CONF_BLOCK_DONE the "}" was found
* NGX_CONF_FILE_DONE the configuration file is done
*/
if (rc == NGX_ERROR) {
goto done;
}
if (rc == NGX_CONF_BLOCK_DONE) {
if (type != parse_block) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unexpected \"}\"");
goto failed;
}
goto done;
}
if (rc == NGX_CONF_FILE_DONE) {
if (type == parse_block) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected end of file, expecting \"}\"");
goto failed;
}
goto done;
}
if (rc == NGX_CONF_BLOCK_START) {
if (type == parse_param) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"block directives are not supported "
"in -g option");
goto failed;
}
}
/* rc == NGX_OK || rc == NGX_CONF_BLOCK_START */
if (cf->handler) {
/*
* the custom handler, i.e., that is used in the http's
* "types { ... }" directive
*/
if (rc == NGX_CONF_BLOCK_START) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unexpected \"{\"");
goto failed;
}
rv = (*cf->handler)(cf, NULL, cf->handler_conf);
if (rv == NGX_CONF_OK) {
continue;
}
if (rv == NGX_CONF_ERROR) {
goto failed;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s", rv);
goto failed;
}
// 重要2: 将解析出的变量进行细致处理
rc = ngx_conf_handler(cf, rc);
if (rc == NGX_ERROR) {
goto failed;
}
}
failed:
rc = NGX_ERROR;
done:
if (filename) {
if (cf->conf_file->buffer->start) {
ngx_free(cf->conf_file->buffer->start);
}
if (ngx_close_file(fd) == NGX_FILE_ERROR) {
ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
ngx_close_file_n " %s failed",
filename->data);
rc = NGX_ERROR;
}
cf->conf_file = prev;
}
if (rc == NGX_ERROR) {
return NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
// 读取一个个地 token 信息
static ngx_int_t
ngx_conf_read_token(ngx_conf_t *cf)
{
u_char *start, ch, *src, *dst;
off_t file_size;
size_t len;
ssize_t n, size;
ngx_uint_t found, need_space, last_space, sharp_comment, variable;
ngx_uint_t quoted, s_quoted, d_quoted, start_line;
ngx_str_t *word;
ngx_buf_t *b, *dump;
found = 0;
need_space = 0;
last_space = 1;
sharp_comment = 0;
variable = 0;
quoted = 0;
s_quoted = 0;
d_quoted = 0;
cf->args->nelts = 0;
b = cf->conf_file->buffer;
dump = cf->conf_file->dump;
start = b->pos;
start_line = cf->conf_file->line;
file_size = ngx_file_size(&cf->conf_file->file.info);
for ( ;; ) {
// last默认是最大buffer,pos默认为0,所以以下逻辑不一定走
if (b->pos >= b->last) {
if (cf->conf_file->file.offset >= file_size) {
if (cf->args->nelts > 0 || !last_space) {
if (cf->conf_file->file.fd == NGX_INVALID_FILE) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected end of parameter, "
"expecting \";\"");
return NGX_ERROR;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected end of file, "
"expecting \";\" or \"}\"");
return NGX_ERROR;
}
return NGX_CONF_FILE_DONE;
}
// 默认两值相等,len为0
len = b->pos - start;
if (len == NGX_CONF_BUFFER) {
cf->conf_file->line = start_line;
if (d_quoted) {
ch = '"';
} else if (s_quoted) {
ch = '\'';
} else {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"too long parameter \"%*s...\" started",
10, start);
return NGX_ERROR;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"too long parameter, probably "
"missing terminating \"%c\" character", ch);
return NGX_ERROR;
}
if (len) {
ngx_memmove(b->start, start, len);
}
// 计算剩余大小
size = (ssize_t) (file_size - cf->conf_file->file.offset);
// 如果剩余大小超出当前缓冲的大小,则只能取当前缓冲剩余大小
if (size > b->end - (b->start + len)) {
size = b->end - (b->start + len);
}
// 从配置文件中读取size大小的数据出来,放到buf中备用,相当于尽量一次全部读取
n = ngx_read_file(&cf->conf_file->file, b->start + len, size,
cf->conf_file->file.offset);
if (n == NGX_ERROR) {
return NGX_ERROR;
}
if (n != size) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
ngx_read_file_n " returned "
"only %z bytes instead of %z",
n, size);
return NGX_ERROR;
}
// 交换各偏移信息
b->pos = b->start + len;
b->last = b->pos + n;
start = b->start;
if (dump) {
dump->last = ngx_cpymem(dump->last, b->pos, size);
}
}
// 从文件中读出一个字符用以判定,即如果假设文件已读取完,则相当于一个个字符取出判定
ch = *b->pos++;
// 遇到换行,line++,注释标识重置
if (ch == LF) {
cf->conf_file->line++;
if (sharp_comment) {
sharp_comment = 0;
}
}
// 如果注释标识有效,则忽略当前段的字符,直到标识被清除
if (sharp_comment) {
continue;
}
// 引号闭合处理
if (quoted) {
quoted = 0;
continue;
}
// 判断是否有新的语句开始,类似空格都可以
if (need_space) {
if (ch == ' ' || ch == '\t' || ch == CR || ch == LF) {
last_space = 1;
need_space = 0;
continue;
}
// 遇到分号,当前解析结束,即得到一个独立语句,如 root /www;
if (ch == ';') {
return NGX_OK;
}
// 遇到块也结束当前解析,交由子处理器处理
if (ch == '{') {
return NGX_CONF_BLOCK_START;
}
if (ch == ')') {
last_space = 1;
need_space = 0;
} else {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected \"%c\"", ch);
return NGX_ERROR;
}
}
if (last_space) {
// 新语句开始,行号暂存
start = b->pos - 1;
start_line = cf->conf_file->line;
// 忽略空格类字符
if (ch == ' ' || ch == '\t' || ch == CR || ch == LF) {
continue;
}
switch (ch) {
case ';':
case '{':
if (cf->args->nelts == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected \"%c\"", ch);
return NGX_ERROR;
}
// 语句结束,nelts 到底是啥?
if (ch == '{') {
return NGX_CONF_BLOCK_START;
}
return NGX_OK;
case '}':
if (cf->args->nelts != 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unexpected \"}\"");
return NGX_ERROR;
}
return NGX_CONF_BLOCK_DONE;
case '#':
sharp_comment = 1;
continue;
case '\\': // 转义符
quoted = 1;
last_space = 0;
continue;
case '"':
start++;
d_quoted = 1;
last_space = 0;
continue;
case '\'':
start++;
s_quoted = 1;
last_space = 0;
continue;
case '$': // 变量解析
variable = 1;
last_space = 0;
continue;
default:
last_space = 0;
}
} else {
// ${xxx} 变量
if (ch == '{' && variable) {
continue;
}
variable = 0;
if (ch == '\\') {
quoted = 1;
continue;
}
if (ch == '$') {
variable = 1;
continue;
}
// 引号处理
if (d_quoted) {
if (ch == '"') {
d_quoted = 0;
need_space = 1;
found = 1;
}
} else if (s_quoted) {
if (ch == '\'') {
s_quoted = 0;
need_space = 1;
found = 1;
}
} else if (ch == ' ' || ch == '\t' || ch == CR || ch == LF
|| ch == ';' || ch == '{')
{
last_space = 1;
found = 1; // 完整解析一个语句
}
if (found) {
word = ngx_array_push(cf->args);
if (word == NULL) {
return NGX_ERROR;
}
word->data = ngx_pnalloc(cf->pool, b->pos - 1 - start + 1);
if (word->data == NULL) {
return NGX_ERROR;
}
// 将解析出的语句赋值到 args 中
for (dst = word->data, src = start, len = 0;
src < b->pos - 1;
len++)
{
if (*src == '\\') {
switch (src[1]) {
case '"':
case '\'':
case '\\':
// 去除转义标识
src++;
break;
case 't':
// 翻译转义
*dst++ = '\t';
src += 2;
continue;
case 'r':
*dst++ = '\r';
src += 2;
continue;
case 'n':
*dst++ = '\n';
src += 2;
continue;
}
}
*dst++ = *src++;
}
*dst = '\0';
word->len = len;
if (ch == ';') {
return NGX_OK;
}
if (ch == '{') {
return NGX_CONF_BLOCK_START;
}
found = 0;
}
}
}
}
大体原理是:读取一个个token,然后进行依次翻译,分小语句,大block,... 类型依次处理。将解析的结果放入cf->args中。其解析结果如 location ~ /api/.*go { ,如 listen 80 81;
还差一个细节,就是读取到token之后,又是如何传递给各模块的呢?实际就是上面的重点2:ngx_conf_handler() 处理。
static ngx_int_t
ngx_conf_handler(ngx_conf_t *cf, ngx_int_t last)
{
char *rv;
void *conf, **confp;
ngx_uint_t i, found;
ngx_str_t *name;
ngx_command_t *cmd;
// 获取最后存入的配置变量名
name = cf->args->elts;
found = 0;
// 遍历模块的 commands 列表,依次调用进行处理, 比如 root /www 处理
// location /api {..} 处理
for (i = 0; cf->cycle->modules[i]; i++) {
cmd = cf->cycle->modules[i]->commands;
if (cmd == NULL) {
continue;
}
for ( /* void */ ; cmd->name.len; cmd++) {
// 名字不同必然不负责解析
if (name->len != cmd->name.len) {
continue;
}
if (ngx_strcmp(name->data, cmd->name.data) != 0) {
continue;
}
found = 1;
// 配置模块处理
if (cf->cycle->modules[i]->type != NGX_CONF_MODULE
&& cf->cycle->modules[i]->type != cf->module_type)
{
continue;
}
/* is the directive's location right ? */
// 变量类型判定
if (!(cmd->type & cf->cmd_type)) {
continue;
}
if (!(cmd->type & NGX_CONF_BLOCK) && last != NGX_OK) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"directive \"%s\" is not terminated by \";\"",
name->data);
return NGX_ERROR;
}
if ((cmd->type & NGX_CONF_BLOCK) && last != NGX_CONF_BLOCK_START) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"directive \"%s\" has no opening \"{\"",
name->data);
return NGX_ERROR;
}
/* is the directive's argument count right ? */
// 参数个数匹配
if (!(cmd->type & NGX_CONF_ANY)) {
if (cmd->type & NGX_CONF_FLAG) {
if (cf->args->nelts != 2) {
goto invalid;
}
} else if (cmd->type & NGX_CONF_1MORE) {
if (cf->args->nelts < 2) {
goto invalid;
}
} else if (cmd->type & NGX_CONF_2MORE) {
if (cf->args->nelts < 3) {
goto invalid;
}
} else if (cf->args->nelts > NGX_CONF_MAX_ARGS) {
goto invalid;
} else if (!(cmd->type & argument_number[cf->args->nelts - 1]))
{
goto invalid;
}
}
/* set up the directive's configuration context */
conf = NULL;
// 找不同的配置级别位置存储(这指针用得6啊)
if (cmd->type & NGX_DIRECT_CONF) {
conf = ((void **) cf->ctx)[cf->cycle->modules[i]->index];
} else if (cmd->type & NGX_MAIN_CONF) {
conf = &(((void **) cf->ctx)[cf->cycle->modules[i]->index]);
} else if (cf->ctx) {
confp = *(void **) ((char *) cf->ctx + cmd->conf);
if (confp) {
conf = confp[cf->cycle->modules[i]->ctx_index];
}
}
// 调用各命令的set方法,处理配置语义
// 实际上就涉及到内嵌套解析问题了
// 同样不会很简单哦
rv = cmd->set(cf, cmd, conf);
if (rv == NGX_CONF_OK) {
return NGX_OK;
}
if (rv == NGX_CONF_ERROR) {
return NGX_ERROR;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"\"%s\" directive %s", name->data, rv);
return NGX_ERROR;
}
}
// 配置使用错误
if (found) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"\"%s\" directive is not allowed here", name->data);
return NGX_ERROR;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unknown directive \"%s\"", name->data);
return NGX_ERROR;
invalid:
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid number of arguments in \"%s\" directive",
name->data);
return NGX_ERROR;
}
将解析出的配置信息接入到各子模块之后,才算是真正意义上的解析成功,也才能被各子模块使用。
下面我们再来看个样例,子模块如何解析配置,http location ....
listen 80; 的解析比较简单些,有兴趣可查看:
static char *
ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_http_core_srv_conf_t *cscf = conf;
ngx_str_t *value, size;
ngx_url_t u;
ngx_uint_t n;
ngx_http_listen_opt_t lsopt;
cscf->listen = 1;
value = cf->args->elts;
ngx_memzero(&u, sizeof(ngx_url_t));
u.url = value[1];
u.listen = 1;
u.default_port = 80;
if (ngx_parse_url(cf->pool, &u) != NGX_OK) {
if (u.err) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"%s in \"%V\" of the \"listen\" directive",
u.err, &u.url);
}
return NGX_CONF_ERROR;
}
ngx_memzero(&lsopt, sizeof(ngx_http_listen_opt_t));
lsopt.backlog = NGX_LISTEN_BACKLOG;
lsopt.rcvbuf = -1;
lsopt.sndbuf = -1;
#if (NGX_HAVE_SETFIB)
lsopt.setfib = -1;
#endif
#if (NGX_HAVE_TCP_FASTOPEN)
lsopt.fastopen = -1;
#endif
#if (NGX_HAVE_INET6)
lsopt.ipv6only = 1;
#endif
// 更多参数解析,见官方文档说明
for (n = 2; n < cf->args->nelts; n++) {
if (ngx_strcmp(value[n].data, "default_server") == 0
|| ngx_strcmp(value[n].data, "default") == 0)
{
lsopt.default_server = 1;
continue;
}
if (ngx_strcmp(value[n].data, "bind") == 0) {
lsopt.set = 1;
lsopt.bind = 1;
continue;
}
#if (NGX_HAVE_SETFIB)
if (ngx_strncmp(value[n].data, "setfib=", 7) == 0) {
lsopt.setfib = ngx_atoi(value[n].data + 7, value[n].len - 7);
lsopt.set = 1;
lsopt.bind = 1;
if (lsopt.setfib == NGX_ERROR) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid setfib \"%V\"", &value[n]);
return NGX_CONF_ERROR;
}
continue;
}
#endif
#if (NGX_HAVE_TCP_FASTOPEN)
if (ngx_strncmp(value[n].data, "fastopen=", 9) == 0) {
lsopt.fastopen = ngx_atoi(value[n].data + 9, value[n].len - 9);
lsopt.set = 1;
lsopt.bind = 1;
if (lsopt.fastopen == NGX_ERROR) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid fastopen \"%V\"", &value[n]);
return NGX_CONF_ERROR;
}
continue;
}
#endif
if (ngx_strncmp(value[n].data, "backlog=", 8) == 0) {
lsopt.backlog = ngx_atoi(value[n].data + 8, value[n].len - 8);
lsopt.set = 1;
lsopt.bind = 1;
if (lsopt.backlog == NGX_ERROR || lsopt.backlog == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid backlog \"%V\"", &value[n]);
return NGX_CONF_ERROR;
}
continue;
}
if (ngx_strncmp(value[n].data, "rcvbuf=", 7) == 0) {
size.len = value[n].len - 7;
size.data = value[n].data + 7;
lsopt.rcvbuf = ngx_parse_size(&size);
lsopt.set = 1;
lsopt.bind = 1;
if (lsopt.rcvbuf == NGX_ERROR) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid rcvbuf \"%V\"", &value[n]);
return NGX_CONF_ERROR;
}
continue;
}
if (ngx_strncmp(value[n].data, "sndbuf=", 7) == 0) {
size.len = value[n].len - 7;
size.data = value[n].data + 7;
lsopt.sndbuf = ngx_parse_size(&size);
lsopt.set = 1;
lsopt.bind = 1;
if (lsopt.sndbuf == NGX_ERROR) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid sndbuf \"%V\"", &value[n]);
return NGX_CONF_ERROR;
}
continue;
}
if (ngx_strncmp(value[n].data, "accept_filter=", 14) == 0) {
#if (NGX_HAVE_DEFERRED_ACCEPT && defined SO_ACCEPTFILTER)
lsopt.accept_filter = (char *) &value[n].data[14];
lsopt.set = 1;
lsopt.bind = 1;
#else
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"accept filters \"%V\" are not supported "
"on this platform, ignored",
&value[n]);
#endif
continue;
}
if (ngx_strcmp(value[n].data, "deferred") == 0) {
#if (NGX_HAVE_DEFERRED_ACCEPT && defined TCP_DEFER_ACCEPT)
lsopt.deferred_accept = 1;
lsopt.set = 1;
lsopt.bind = 1;
#else
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"the deferred accept is not supported "
"on this platform, ignored");
#endif
continue;
}
if (ngx_strncmp(value[n].data, "ipv6only=o", 10) == 0) {
#if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
if (ngx_strcmp(&value[n].data[10], "n") == 0) {
lsopt.ipv6only = 1;
} else if (ngx_strcmp(&value[n].data[10], "ff") == 0) {
lsopt.ipv6only = 0;
} else {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid ipv6only flags \"%s\"",
&value[n].data[9]);
return NGX_CONF_ERROR;
}
lsopt.set = 1;
lsopt.bind = 1;
continue;
#else
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"ipv6only is not supported "
"on this platform");
return NGX_CONF_ERROR;
#endif
}
if (ngx_strcmp(value[n].data, "reuseport") == 0) {
#if (NGX_HAVE_REUSEPORT)
lsopt.reuseport = 1;
lsopt.set = 1;
lsopt.bind = 1;
#else
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"reuseport is not supported "
"on this platform, ignored");
#endif
continue;
}
if (ngx_strcmp(value[n].data, "ssl") == 0) {
#if (NGX_HTTP_SSL)
lsopt.ssl = 1;
continue;
#else
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"the \"ssl\" parameter requires "
"ngx_http_ssl_module");
return NGX_CONF_ERROR;
#endif
}
if (ngx_strcmp(value[n].data, "http2") == 0) {
#if (NGX_HTTP_V2)
lsopt.http2 = 1;
continue;
#else
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"the \"http2\" parameter requires "
"ngx_http_v2_module");
return NGX_CONF_ERROR;
#endif
}
if (ngx_strcmp(value[n].data, "spdy") == 0) {
ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
"invalid parameter \"spdy\": "
"ngx_http_spdy_module was superseded "
"by ngx_http_v2_module");
continue;
}
if (ngx_strncmp(value[n].data, "so_keepalive=", 13) == 0) {
if (ngx_strcmp(&value[n].data[13], "on") == 0) {
lsopt.so_keepalive = 1;
} else if (ngx_strcmp(&value[n].data[13], "off") == 0) {
lsopt.so_keepalive = 2;
} else {
#if (NGX_HAVE_KEEPALIVE_TUNABLE)
u_char *p, *end;
ngx_str_t s;
end = value[n].data + value[n].len;
s.data = value[n].data + 13;
p = ngx_strlchr(s.data, end, ':');
if (p == NULL) {
p = end;
}
if (p > s.data) {
s.len = p - s.data;
lsopt.tcp_keepidle = ngx_parse_time(&s, 1);
if (lsopt.tcp_keepidle == (time_t) NGX_ERROR) {
goto invalid_so_keepalive;
}
}
s.data = (p < end) ? (p + 1) : end;
p = ngx_strlchr(s.data, end, ':');
if (p == NULL) {
p = end;
}
if (p > s.data) {
s.len = p - s.data;
lsopt.tcp_keepintvl = ngx_parse_time(&s, 1);
if (lsopt.tcp_keepintvl == (time_t) NGX_ERROR) {
goto invalid_so_keepalive;
}
}
s.data = (p < end) ? (p + 1) : end;
if (s.data < end) {
s.len = end - s.data;
lsopt.tcp_keepcnt = ngx_atoi(s.data, s.len);
if (lsopt.tcp_keepcnt == NGX_ERROR) {
goto invalid_so_keepalive;
}
}
if (lsopt.tcp_keepidle == 0 && lsopt.tcp_keepintvl == 0
&& lsopt.tcp_keepcnt == 0)
{
goto invalid_so_keepalive;
}
lsopt.so_keepalive = 1;
#else
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"the \"so_keepalive\" parameter accepts "
"only \"on\" or \"off\" on this platform");
return NGX_CONF_ERROR;
#endif
}
lsopt.set = 1;
lsopt.bind = 1;
continue;
#if (NGX_HAVE_KEEPALIVE_TUNABLE)
invalid_so_keepalive:
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid so_keepalive value: \"%s\"",
&value[n].data[13]);
return NGX_CONF_ERROR;
#endif
}
if (ngx_strcmp(value[n].data, "proxy_protocol") == 0) {
lsopt.proxy_protocol = 1;
continue;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid parameter \"%V\"", &value[n]);
return NGX_CONF_ERROR;
}
// 将监听端口加入列表
for (n = 0; n < u.naddrs; n++) {
lsopt.sockaddr = u.addrs[n].sockaddr;
lsopt.socklen = u.addrs[n].socklen;
lsopt.addr_text = u.addrs[n].name;
lsopt.wildcard = ngx_inet_wildcard(lsopt.sockaddr);
if (ngx_http_add_listen(cf, cscf, &lsopt) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
return NGX_CONF_OK;
}
location 的解析则肯定会复杂很多,因为它是一个块级的配置,内部将会有很多复杂的配置,想想这必然又涉及到递归解析了。
// location /xx {..} 的解析
static char *
ngx_http_core_location(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
{
char *rv;
u_char *mod;
size_t len;
ngx_str_t *value, *name;
ngx_uint_t i;
ngx_conf_t save;
ngx_http_module_t *module;
ngx_http_conf_ctx_t *ctx, *pctx;
ngx_http_core_loc_conf_t *clcf, *pclcf;
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t));
if (ctx == NULL) {
return NGX_CONF_ERROR;
}
pctx = cf->ctx;
ctx->main_conf = pctx->main_conf;
ctx->srv_conf = pctx->srv_conf;
ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module);
if (ctx->loc_conf == NULL) {
return NGX_CONF_ERROR;
}
// 嵌套解析
for (i = 0; cf->cycle->modules[i]; i++) {
if (cf->cycle->modules[i]->type != NGX_HTTP_MODULE) {
continue;
}
module = cf->cycle->modules[i]->ctx;
if (module->create_loc_conf) {
// 将解析的值放入 ctx 中,备用
ctx->loc_conf[cf->cycle->modules[i]->ctx_index] =
module->create_loc_conf(cf);
if (ctx->loc_conf[cf->cycle->modules[i]->ctx_index] == NULL) {
return NGX_CONF_ERROR;
}
}
}
clcf = ctx->loc_conf[ngx_http_core_module.ctx_index];
clcf->loc_conf = ctx->loc_conf;
value = cf->args->elts;
if (cf->args->nelts == 3) {
len = value[1].len;
mod = value[1].data;
name = &value[2];
// 疏松写法
// uri 模式匹配
if (len == 1 && mod[0] == '=') {
clcf->name = *name;
clcf->exact_match = 1;
} else if (len == 2 && mod[0] == '^' && mod[1] == '~') {
clcf->name = *name;
clcf->noregex = 1;
} else if (len == 1 && mod[0] == '~') {
if (ngx_http_core_regex_location(cf, clcf, name, 0) != NGX_OK) {
return NGX_CONF_ERROR;
}
} else if (len == 2 && mod[0] == '~' && mod[1] == '*') {
if (ngx_http_core_regex_location(cf, clcf, name, 1) != NGX_OK) {
return NGX_CONF_ERROR;
}
} else {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid location modifier \"%V\"", &value[1]);
return NGX_CONF_ERROR;
}
} else {
name = &value[1];
// 紧密写法
if (name->data[0] == '=') {
clcf->name.len = name->len - 1;
clcf->name.data = name->data + 1;
clcf->exact_match = 1;
} else if (name->data[0] == '^' && name->data[1] == '~') {
clcf->name.len = name->len - 2;
clcf->name.data = name->data + 2;
clcf->noregex = 1;
} else if (name->data[0] == '~') {
name->len--;
name->data++;
if (name->data[0] == '*') {
name->len--;
name->data++;
if (ngx_http_core_regex_location(cf, clcf, name, 1) != NGX_OK) {
return NGX_CONF_ERROR;
}
} else {
if (ngx_http_core_regex_location(cf, clcf, name, 0) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
} else {
clcf->name = *name;
if (name->data[0] == '@') {
clcf->named = 1;
}
}
}
pclcf = pctx->loc_conf[ngx_http_core_module.ctx_index];
if (cf->cmd_type == NGX_HTTP_LOC_CONF) {
/* nested location */
#if 0
clcf->prev_location = pclcf;
#endif
if (pclcf->exact_match) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"location \"%V\" cannot be inside "
"the exact location \"%V\"",
&clcf->name, &pclcf->name);
return NGX_CONF_ERROR;
}
if (pclcf->named) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"location \"%V\" cannot be inside "
"the named location \"%V\"",
&clcf->name, &pclcf->name);
return NGX_CONF_ERROR;
}
if (clcf->named) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"named location \"%V\" can be "
"on the server level only",
&clcf->name);
return NGX_CONF_ERROR;
}
len = pclcf->name.len;
#if (NGX_PCRE)
if (clcf->regex == NULL
&& ngx_filename_cmp(clcf->name.data, pclcf->name.data, len) != 0)
#else
if (ngx_filename_cmp(clcf->name.data, pclcf->name.data, len) != 0)
#endif
{
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"location \"%V\" is outside location \"%V\"",
&clcf->name, &pclcf->name);
return NGX_CONF_ERROR;
}
}
// 添加到location列表中,备用
if (ngx_http_add_location(cf, &pclcf->locations, clcf) != NGX_OK) {
return NGX_CONF_ERROR;
}
save = *cf;
cf->ctx = ctx;
cf->cmd_type = NGX_HTTP_LOC_CONF;
// 递归解析
rv = ngx_conf_parse(cf, NULL);
*cf = save;
return rv;
}
同样,它会遍历其http模块下有哪些可以解析的命令,然后交其处理,然后再处理自身的逻辑。从而完成整个块的配置解析。
4. location配置的应用
上一节已经解析出location的各项配置了,那么它是如何运用到实际中呢?实际上,就是在需要的时候,从相应配置变量中取出来使用判定即可。
腾讯、阿里、滴滴后台面试题汇总总结 — (含答案)
面试:史上最全多线程面试题 !
最新阿里内推Java后端面试题
JVM难学?那是因为你没认真看完这篇文章
关注作者微信公众号 —《JAVA烂猪皮》
了解更多java后端架构知识以及最新面试宝典
看完本文记得给作者点赞+在看哦~~~大家的支持,是作者源源不断出文的动力
作者:等你归去来
出处:https://www.cnblogs.com/yougewe/p/14289846.html