nginx的configure流程

時間 2019-11-29

原文原文鏈接

configure配置

nginx的編譯過程，第一步是configure。咱們使用 --help能夠看到configure的不少配置。linux

configure的過程作的事情其實就是檢測環境，而後根據環境生成Makefile，包含各類參數的c頭文件等（ngx_auto_config.h/ ngx_auto_headers.h）。這個c頭文件包含了全部根據當前環境配置的參數。nginx

configure命令以後多了些什麼？

多了一個Makefile文件

這裏的Makefile文件指的是根目錄下的Makefile, 這個是後面make命令的入口git

多了一個objs文件夾

objs文件夾裏面有這幾個文件：github

autoconf.err

configure過程當中不單單是使用簡單的shell命令來檢測環境，還會生成一些簡單的c程序，而且用編譯器編譯執行，獲取輸出來獲取環境參數。只是這些c程序和編譯後的文件在獲取參數完成以後會刪除，因此咱們實際看不到這個文件的存在。shell

這些shell命令，c程序的一些輸出和錯誤信息都記錄在這個autoconf.err中了，實際上這個文件沒有什麼用。測試

Makefile

這個obj/Makefile纔是本質的構建程序和模塊的過程。全部須要加載的模塊和一些設置都在這邊了。ui

咱們能夠看一下，它使用的編譯器是cc， cc編譯器在linux上就是gcc。 gcc是一個各類不一樣語言的編譯器。gcc表明 the GNU Compiler Collection。好比你的代碼後綴是.c，它會調用c的編譯器還有linker去連接c的庫。atom

nginx_auto_config.h

這個就是configure出來的一個重要成果，本機環境的一些配置，好比int多少位之類的。.net

nginx_auto_headers.h

這個是configure出來的，判斷一些header是否存在。3d

nginx_modules.c

這個文件就告訴咱們了咱們此次編譯nginx到底有多少個模塊。

其中的一些模塊是很重要的，可是咱們也能夠自主選擇。

configure的語法

have + auto/define 語法

have=NGX_SBIN_PATH value="\"$NGX_SBIN_PATH\"" . auto/define

auto/define的定義：

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


cat << END >> $NGX_AUTO_CONFIG_H

#ifndef $have
#define $have  $value
#endif

END

結合起來的意思就是，若是我在參數裏面設置了NGX_SBIN_PATH（有參數能夠設置），那麼我就在ngx_auto_config.h中增長這個宏定義：

#ifndef NGX_SBIN_PATH
#define NGX_SBIN_PATH  "sbin/nginx"
#endif

have + auto/have 語法

cat << END >> $NGX_AUTO_CONFIG_H

#ifndef $have
#define $have  1
#endif

END

意思其實就是auto/define的翻版，只是若是這裏的value是1

好比

have=NGX_HAVE_EPOLL . auto/have

等同

#ifndef NGX_HAVE_EPOLL
#define NGX_HAVE_EPOLL  1
#endif

auto/feature

ngx_feature="GeoIP IPv6 support"
ngx_feature_name="NGX_HAVE_GEOIP_V6"
ngx_feature_run=no
ngx_feature_incs="#include <stdio.h>
                  #include <GeoIP.h>"
#ngx_feature_path=
#ngx_feature_libs=
ngx_feature_test="printf(\"%d\", GEOIP_CITY_EDITION_REV0_V6);"
. auto/feature

上面這個是個feature的模版，它的目的是爲了檢查當前的環境是否包含這個feature, 好比上面的例子就是判斷這個機器環境是否支持GEO IPV6。

還能夠看看下面這個例子：

ngx_feature="GeoIP library in /opt/local/"
ngx_feature_path="/opt/local/include"

if [ $NGX_RPATH = YES ]; then
    ngx_feature_libs="-R/opt/local/lib -L/opt/local/lib -lGeoIP"
else
    ngx_feature_libs="-L/opt/local/lib -lGeoIP"
fi

. auto/feature

feature的代碼就不貼出來了, 具體作了下面幾個事情：

控制檯先輸出checking for
在auto_config.err中輸出checking for
檢查變量$ngx_feature_name是否有設置
若是設置了ngx_feature_path，就設置ngx_feature_inc_path
根據$ngx_feature_test生成測試c文件
編譯生成的測試c文件
執行測試c文件並捕獲輸出到auto_config.err
若是設置了ngx_feature_run, 就把輸出設置爲對應的$ngx_feature_name的值
沒有找到的狀況，在auto_config.err中體現，而且在控制檯顯示 not found
刪除測試c文件及編譯出來的東西

auto/include

ngx_include="inttypes.h";    . auto/include

生成一個簡單的c文件：

cat << END > $NGX_AUTOTEST.c

$NGX_INCLUDE_SYS_PARAM_H
#include <$ngx_include>

int main(void) {
    return 0;
}

END

判斷檢測環境是否有這個頭文件。

auto/module

ngx_module_type=HTTP

if :; then
    ngx_module_name="ngx_http_module \
                     ngx_http_core_module \
                     ngx_http_log_module \
                     ngx_http_upstream_module"
    ngx_module_incs="src/http src/http/modules"
    ngx_module_deps="src/http/ngx_http.h \
                     src/http/ngx_http_request.h \
                     src/http/ngx_http_config.h \
                     src/http/ngx_http_core_module.h \
                     src/http/ngx_http_cache.h \
                     src/http/ngx_http_variables.h \
                     src/http/ngx_http_script.h \
                     src/http/ngx_http_upstream.h \
                     src/http/ngx_http_upstream_round_robin.h"
    ngx_module_srcs="src/http/ngx_http.c \
                     src/http/ngx_http_core_module.c \
                     src/http/ngx_http_special_response.c \
                     src/http/ngx_http_request.c \
                     src/http/ngx_http_parse.c \
                     src/http/modules/ngx_http_log_module.c \
                     src/http/ngx_http_request_body.c \
                     src/http/ngx_http_variables.c \
                     src/http/ngx_http_script.c \
                     src/http/ngx_http_upstream.c \
                     src/http/ngx_http_upstream_round_robin.c"
    ngx_module_libs=
    ngx_module_link=YES

    . auto/module

這個auto/module會對每個模塊設置一些模塊須要的變量，好比模塊的源碼地址，模塊依賴的lib庫等。

控制檯輸出：

checking for OS
 + Linux 3.10.0-514.16.1.el7.x86_64 x86_64
checking for C compiler ... found
 + using GNU C compiler
 + gcc version: 4.4.7 20120313 (Red Hat 4.4.7-18) (GCC)
checking for gcc -pipe switch ... found
checking for -Wl,-E switch ... found
checking for gcc builtin atomic operations ... found
checking for C99 variadic macros ... found
checking for gcc variadic macros ... found
checking for gcc builtin 64 bit byteswap ... found
checking for unistd.h ... found
checking for inttypes.h ... found
checking for limits.h ... found
checking for sys/filio.h ... not found
checking for sys/param.h ... found
checking for sys/mount.h ... found
checking for sys/statvfs.h ... found
checking for crypt.h ... found
checking for Linux specific features
checking for epoll ... found
checking for EPOLLRDHUP ... found
checking for EPOLLEXCLUSIVE ... not found
checking for O_PATH ... not found
checking for sendfile() ... found
checking for sendfile64() ... found
checking for sys/prctl.h ... found
checking for prctl(PR_SET_DUMPABLE) ... found
checking for prctl(PR_SET_KEEPCAPS) ... found
checking for capabilities ... found
checking for crypt_r() ... found
checking for sys/vfs.h ... found
checking for nobody group ... found
checking for poll() ... found
checking for /dev/poll ... not found
checking for kqueue ... not found
checking for crypt() ... not found
checking for crypt() in libcrypt ... found
checking for F_READAHEAD ... not found
checking for posix_fadvise() ... found
checking for O_DIRECT ... found
checking for F_NOCACHE ... not found
checking for directio() ... not found
checking for statfs() ... found
checking for statvfs() ... found
checking for dlopen() ... not found
checking for dlopen() in libdl ... found
checking for sched_yield() ... found
checking for sched_setaffinity() ... found
checking for SO_SETFIB ... not found
checking for SO_REUSEPORT ... found
checking for SO_ACCEPTFILTER ... not found
checking for SO_BINDANY ... not found
checking for IP_TRANSPARENT ... found
checking for IP_BINDANY ... not found
checking for IP_BIND_ADDRESS_NO_PORT ... not found
checking for IP_RECVDSTADDR ... not found
checking for IP_SENDSRCADDR ... not found
checking for IP_PKTINFO ... found
checking for IPV6_RECVPKTINFO ... found
checking for TCP_DEFER_ACCEPT ... found
checking for TCP_KEEPIDLE ... found
checking for TCP_FASTOPEN ... not found
checking for TCP_INFO ... found
checking for accept4() ... found
checking for eventfd() ... found
checking for int size ... 4 bytes
checking for long size ... 8 bytes
checking for long long size ... 8 bytes
checking for void * size ... 8 bytes
checking for uint32_t ... found
checking for uint64_t ... found
checking for sig_atomic_t ... found
checking for sig_atomic_t size ... 4 bytes
checking for socklen_t ... found
checking for in_addr_t ... found
checking for in_port_t ... found
checking for rlim_t ... found
checking for uintptr_t ... uintptr_t found
checking for system byte ordering ... little endian
checking for size_t size ... 8 bytes
checking for off_t size ... 8 bytes
checking for time_t size ... 8 bytes
checking for AF_INET6 ... found
checking for setproctitle() ... not found
checking for pread() ... found
checking for pwrite() ... found
checking for pwritev() ... found
checking for sys_nerr ... found
checking for localtime_r() ... found
checking for clock_gettime(CLOCK_MONOTONIC) ... not found
checking for clock_gettime(CLOCK_MONOTONIC) in librt ... found
checking for posix_memalign() ... found
checking for memalign() ... found
checking for mmap(MAP_ANON|MAP_SHARED) ... found
checking for mmap("/dev/zero", MAP_SHARED) ... found
checking for System V shared memory ... found
checking for POSIX semaphores ... not found
checking for POSIX semaphores in libpthread ... found
checking for struct msghdr.msg_control ... found
checking for ioctl(FIONBIO) ... found
checking for struct tm.tm_gmtoff ... found
checking for struct dirent.d_namlen ... not found
checking for struct dirent.d_type ... found
checking for sysconf(_SC_NPROCESSORS_ONLN) ... found
checking for sysconf(_SC_LEVEL1_DCACHE_LINESIZE) ... found
checking for openat(), fstatat() ... found
checking for getaddrinfo() ... found
checking for zlib library ... found
creating objs/Makefile

Configuration summary
  + PCRE library is not used
  + OpenSSL library is not used
  + using system zlib library

  nginx path prefix: "/usr/local/nginx"
  nginx binary file: "/usr/local/nginx/sbin/nginx"
  nginx modules path: "/usr/local/nginx/modules"
  nginx configuration prefix: "/usr/local/nginx/conf"
  nginx configuration file: "/usr/local/nginx/conf/nginx.conf"
  nginx pid file: "/usr/local/nginx/logs/nginx.pid"
  nginx error log file: "/usr/local/nginx/logs/error.log"
  nginx http access log file: "/usr/local/nginx/logs/access.log"
  nginx http client request body temporary files: "client_body_temp"
  nginx http proxy temporary files: "proxy_temp"
  nginx http fastcgi temporary files: "fastcgi_temp"
  nginx http uwsgi temporary files: "uwsgi_temp"
  nginx http scgi temporary files: "scgi_temp

咱們其實能夠對着 xmind 的流程和 configure 這個程序來看就很清晰了

https://github.com/its-tech/nginx-1.14.0-research/blob/master/configure

再加上前面幾個configure語法就能看懂了。