Hi agentzh，
我在开发自己的nginx日志模块中遇到一个问题，难以解决，希望得到agentzh指点。模块大体流程见附件（附件中只是一个大体的原型，用于梳理模块流程，真正模块会采用单独io线程异步写磁盘）。描述如下：
http {
...
log_set /tmp/tmp.log info 1M;
...
server {
location /test1 {
alog info "hello";
access_by_lua '
ngx.location.capture("/test2")
';
alog info "alog";
...
}
location /test2 {
alog info "world";
...
}
}
}
原本期望输出：
hello
world
alog
但实际上只输出了：
hello
alog
location /test2 中的日志无法输出。
发现proxy_pass没有这种问题，因为proxy_pass又是一次完整的location请求，但这种内部跳转不知道怎么解决。请问agentzh和各位朋友，我怎么样才能感知到某次访问中，location之间的跳转关系呢？
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#define NGX_ALOG_ERR 0
#define NGX_ALOG_WARN 1
#define NGX_ALOG_INFO 2
#define NGX_ALOG_DEBUG 3
typedef struct {
u_char *start;
u_char *pos;
} ngx_http_alog_buf_t;
typedef struct {
ngx_open_file_t *log_file;
ngx_uint_t log_level;
ngx_uint_t buf_size;
ngx_http_alog_buf_t log_buf;
} ngx_http_alog_main_conf_t;
typedef struct {
ngx_str_t raw_value; /* store raw str value */
ngx_array_t *lengths;
ngx_array_t *values;
} ngx_http_alog_script_t;
typedef struct {
ngx_http_alog_script_t *script; /* nginx variables */
ngx_uint_t level;
unsigned flush:1;
} ngx_http_alog_t;
typedef struct {
ngx_array_t *logs; /* array of ngx_http_alog_t */
} ngx_http_alog_loc_conf_t;
static char *ngx_http_alog_set_log(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static char *ngx_http_alog_write_log(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
static ngx_command_t ngx_http_alog_commands[] = {
{ ngx_string("alog_set"),
NGX_HTTP_MAIN_CONF | NGX_CONF_1MORE,
ngx_http_alog_set_log,
NGX_HTTP_MAIN_CONF_OFFSET,
0,
NULL },
{ ngx_string("alog"),
NGX_HTTP_LOC_CONF | NGX_CONF_2MORE,
ngx_http_alog_write_log,
NGX_HTTP_LOC_CONF_OFFSET,
0,
NULL },
ngx_null_command
};
static ngx_int_t ngx_http_alog_init(ngx_conf_t *cf);
static void *ngx_http_alog_create_main_conf(ngx_conf_t *cf);
static void *ngx_http_alog_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_alog_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child);
static ngx_http_module_t ngx_http_alog_module_ctx = {
NULL, /* preconfiguration */
ngx_http_alog_init, /* postconfiguration */
ngx_http_alog_create_main_conf, /* create main configuration */
NULL, /* init main configuration */
NULL, /* create server configuration */
NULL, /* merge server configuration */
ngx_http_alog_create_loc_conf, /* create location configuration */
ngx_http_alog_merge_loc_conf, /* merge location configuration */
};
static void ngx_http_alog_exit(ngx_cycle_t * cycle);
ngx_module_t ngx_http_alog_module = {
NGX_MODULE_V1,
&ngx_http_alog_module_ctx, /* module context */
ngx_http_alog_commands, /* module directives */
NGX_HTTP_MODULE, /* module type */
NULL, /* init master */
NULL, /* init module */
NULL, /* init process */
NULL, /* init thread */
NULL, /* exit thread */
ngx_http_alog_exit, /* exit process */
ngx_http_alog_exit, /* exit master */
NGX_MODULE_V1_PADDING
};
static ngx_int_t ngx_http_alog_write(ngx_http_request_t *r, u_char *buf, size_t len, unsigned flush);
static ngx_int_t ngx_http_alog_handler(ngx_http_request_t *r)
{
u_char *line, *p;
ngx_str_t *computed_log;
ngx_uint_t l, log_msg_len;
ngx_http_alog_t *log;
ngx_http_alog_main_conf_t *lmcf;
ngx_http_alog_loc_conf_t *llcf;
lmcf = ngx_http_get_module_main_conf(r, ngx_http_alog_module);
llcf = ngx_http_get_module_loc_conf(r, ngx_http_alog_module);
log = llcf->logs->elts;
for (l = 0; l < llcf->logs->nelts; l++) {
/* if current log level less than log_level setting, just skip */
if (log[l].level < lmcf->log_level) {
continue;
}
computed_log = NULL;
if (log[l].script->lengths == NULL) {
computed_log = &(log[l].script->raw_value);
} else {
computed_log = ngx_pcalloc(r->pool, sizeof(ngx_str_t));
if (computed_log == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
if (ngx_http_script_run(r, computed_log, log[l].script->lengths->elts, 0, log[l].script->values->elts) == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
}
if (computed_log == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
log_msg_len = computed_log->len;
log_msg_len += NGX_LINEFEED_SIZE;
line = ngx_pcalloc(r->pool, log_msg_len);
if (line == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
p = line;
p = ngx_cpymem(line, computed_log->data, computed_log->len);
ngx_linefeed(p);
if (ngx_http_alog_write(r, line, log_msg_len, log[l].flush) != (ngx_int_t)log_msg_len) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
}
return NGX_OK;
}
static ngx_int_t ngx_http_alog_write(ngx_http_request_t *r, u_char *buf, size_t len, unsigned flush)
{
ngx_http_alog_main_conf_t *lmcf;
size_t write_bytes, retval_len;
lmcf = ngx_http_get_module_main_conf(r, ngx_http_alog_module);
if (lmcf->buf_size == 0) {
retval_len = write(lmcf->log_file->fd, buf, len);
} else {
/* log msg is too long to put into log buffer */
if (len > lmcf->buf_size) {
return 0;
}
/* left space of log buffer can not store current log msg */
if (((lmcf->log_buf.pos - lmcf->log_buf.start) + len) > lmcf->buf_size) {
write_bytes = lmcf->log_buf.pos - lmcf->log_buf.start;
write(lmcf->log_file->fd, lmcf->log_buf.start, write_bytes);
lmcf->log_buf.pos = lmcf->log_buf.start;
}
lmcf->log_buf.pos = ngx_cpymem(lmcf->log_buf.pos, buf, len);
retval_len = len;
if (flush) {
write_bytes = lmcf->log_buf.pos - lmcf->log_buf.start;
retval_len = write(lmcf->log_file->fd, lmcf->log_buf.start, write_bytes);
lmcf->log_buf.pos = lmcf->log_buf.start;
}
}
return retval_len;
}
static void *ngx_http_alog_create_main_conf(ngx_conf_t *cf)
{
ngx_http_alog_main_conf_t *conf;
conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_alog_main_conf_t));
if (conf == NULL) {
return NULL;
}
/*
* set by ngx_pcalloc():
*
* conf->log_file = NULL;
*
* conf->log_buf.start = NULL;
* conf->log_buf.pos = NULL;
*/
conf->log_level = NGX_CONF_UNSET_UINT;
conf->buf_size = NGX_CONF_UNSET_UINT;
return conf;
}
static void *ngx_http_alog_create_loc_conf(ngx_conf_t *cf)
{
ngx_http_alog_loc_conf_t *conf;
conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_alog_loc_conf_t));
if (conf == NULL) {
return NULL;
}
/*
* set by ngx_pcalloc():
*
* conf->logs = NULL;
*/
return conf;
}
static char *ngx_http_alog_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
{
ngx_http_alog_loc_conf_t *conf = child;
if (conf->logs == NULL) {
conf->logs = ngx_array_create(cf->pool, 2, sizeof(ngx_http_alog_t));
if (conf->logs == NULL) {
return NGX_CONF_ERROR;
}
}
return NGX_CONF_OK;
}
static ngx_uint_t alog_parse_log_level(ngx_str_t *s)
{
ngx_uint_t log_level;
if (s->data == NULL || s->len == 0) {
return NGX_CONF_UNSET_UINT;
}
if (ngx_strncasecmp(s->data, (u_char *) "DEBUG", 5) == 0) {
log_level = NGX_ALOG_DEBUG;
} else if (ngx_strncasecmp(s->data, (u_char *) "INFO", 4) == 0) {
log_level = NGX_ALOG_INFO;
} else if (ngx_strncasecmp(s->data, (u_char *) "WARN", 4) == 0 || ngx_strncasecmp(s->data, (u_char *) "WARNING", 7) == 0) {
log_level = NGX_ALOG_WARN;
} else if (ngx_strncasecmp(s->data, (u_char *) "ERR", 3) == 0 || ngx_strncasecmp(s->data, (u_char *) "ERROR", 5) == 0) {
log_level = NGX_ALOG_ERR;
} else {
return NGX_CONF_UNSET_UINT;
}
return log_level;
}
static char *ngx_http_alog_set_log(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_http_alog_main_conf_t *lmcf = conf;
ngx_str_t *value;
if (cf->cmd_type != NGX_HTTP_MAIN_CONF) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "the \"alog_set\" directive can be used only on \"http\" level");
return NGX_CONF_ERROR;
}
if (cf->args->nelts > 4) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid alog_set call, usage: alog_set [file_path] [log_level] [buffer_size]");
return NGX_CONF_ERROR;
}
value = cf->args->elts;
if (value[1].data == NULL || value[1].len == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "alog log file path can not be empty");
return NGX_CONF_ERROR;
}
if (lmcf->log_file != NULL) {
return "is duplicate";
}
lmcf->log_file = ngx_conf_open_file(cf->cycle, &value[1]);
if (lmcf->log_file == NULL) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno, ngx_open_file_n" \"%s\" failed", value[1].data);
return NGX_CONF_ERROR;
}
lmcf->log_level = NGX_ALOG_INFO; /* defalut log level */
if (cf->args->nelts >= 3) {
lmcf->log_level = alog_parse_log_level(&value[2]);
if (lmcf->log_level == NGX_CONF_UNSET_UINT) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid alog level \"%s\" failed", value[2].data);
return NGX_CONF_ERROR;
}
}
lmcf->buf_size = 0; /* default not use buffer */
if (cf->args->nelts == 4) {
ssize_t size = ngx_parse_size(&value[3]);
if (size == NGX_ERROR) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid alog buffer size \"%V\"", &value[3]);
return NGX_CONF_ERROR;
}
lmcf->buf_size = size;
if (size != 0) {
lmcf->log_buf.start = ngx_pcalloc(cf->pool, size);
if (lmcf->log_buf.start == NULL) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "alloc alog log buffer fail");
return NGX_CONF_ERROR;
}
lmcf->log_buf.pos = lmcf->log_buf.start;
}
}
return NGX_CONF_OK;
}
static char *ngx_http_alog_write_log(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_http_alog_main_conf_t *lmcf;
ngx_http_alog_loc_conf_t *llcf;
ngx_str_t *value;
ngx_http_alog_t *log;
ngx_uint_t log_level;
unsigned flush;
ngx_http_script_compile_t sc;
ngx_uint_t n;
lmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_alog_module);
llcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_alog_module);
if (cf->cmd_type != NGX_HTTP_LOC_CONF) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "the \"alog\" directive can be used only on \"location\" level");
return NGX_CONF_ERROR;
}
if (cf->args->nelts > 4) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid alog call, usage: alog [log_level] [log_msg] [flush]");
return NGX_CONF_ERROR;
}
if (lmcf->log_file == NULL) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "the \"alog_set\" directive is missing. You should call it in http before using alog");
return NGX_CONF_ERROR;
}
value = cf->args->elts;
log_level = alog_parse_log_level(&value[1]);
if (log_level == NGX_CONF_UNSET_UINT) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid alog level \"%s\" failed", value[1].data);
return NGX_CONF_ERROR;
}
flush = 0;
if (cf->args->nelts == 4) {
if (ngx_strncasecmp(value[3].data, (u_char *) "FLUSH", 4) == 0) {
flush = 1;
} else {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid alog flush flag value, use \"flush\" only");
return NGX_CONF_ERROR;
}
}
if (log_level < lmcf->log_level) {
return NGX_CONF_OK;
}
if (llcf->logs == NULL) {
llcf->logs = ngx_array_create(cf->pool, 2, sizeof(ngx_http_alog_t));
if (llcf->logs == NULL) {
return NGX_CONF_ERROR;
}
}
log = ngx_array_push(llcf->logs);
if (log == NULL) {
return NGX_CONF_ERROR;
}
log->level = log_level;
log->flush = flush;
log->script = ngx_pcalloc(cf->pool, sizeof(ngx_http_alog_script_t));
if (log->script == NULL) {
return NGX_CONF_ERROR;
}
/* store raw str value of arg */
log->script->raw_value = value[2];
n = ngx_http_script_variables_count(&value[2]);
if (n > 0) {
ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));
sc.cf = cf;
sc.source = &(log->script->raw_value);
sc.lengths = &(log->script->lengths);
sc.values = &(log->script->values);
sc.variables = n;
sc.complete_lengths = 1;
sc.complete_values = 1;
if (ngx_http_script_compile(&sc) != NGX_OK) {
return NGX_CONF_ERROR;
}
}
return NGX_CONF_OK;
}
static ngx_int_t ngx_http_alog_init(ngx_conf_t *cf)
{
ngx_http_core_main_conf_t *cmcf;
ngx_http_handler_pt *h;
cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
h = ngx_array_push(&cmcf->phases[NGX_HTTP_LOG_PHASE].handlers);
if (h == NULL) {
return NGX_ERROR;
}
*h = ngx_http_alog_handler;
return NGX_OK;
}
static void ngx_http_alog_exit(ngx_cycle_t * cycle)
{
ngx_http_alog_main_conf_t *lmcf;
size_t write_bytes;
lmcf = (ngx_http_alog_main_conf_t *) ngx_http_cycle_get_module_main_conf(cycle, ngx_http_alog_module);
if (lmcf == NULL) {
return;
}
if (lmcf->buf_size != 0 && lmcf->log_buf.pos != lmcf->log_buf.start) {
write_bytes = lmcf->log_buf.pos - lmcf->log_buf.start;
write(lmcf->log_file->fd, lmcf->log_buf.start, write_bytes);
lmcf->log_buf.pos = lmcf->log_buf.start;
}
}
/*
* vim: ts=8 sw=8 expandtab fenc=utf-8
*/
