static char *
ngx_stream_proxy_pass(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
ngx_stream_proxy_srv_conf_t *pscf = conf;
ngx_url_t u;
ngx_str_t *value, *url;
ngx_stream_core_srv_conf_t *cscf;
if (pscf->upstream) {
return "is duplicate";
}
cscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_core_module);
cscf->handler = ngx_stream_proxy_handler;
value = cf->args->elts;
url = &value[1];
ngx_memzero(&u, sizeof(ngx_url_t));
u.url = *url;
u.no_resolve = 1;
pscf->upstream = ngx_stream_upstream_add(cf, &u, 0);
if (pscf->upstream == NULL) {
return NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
static char *
ngx_stream_upm_parse(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
u_short port;
ngx_int_t add = 0;
ngx_url_t *u;
ngx_str_t *value, *url;
ngx_stream_upm_main_conf_t *ummcf = conf;
if (ummcf->upstream) {
return "is duplicate";
}
if (cf->args->nelts != 2) {
return "With Invalid command args";
}
value = cf->args->elts;
url = &value[1];
ummcf->um_url = ngx_pcalloc(cf->pool, sizeof(ngx_url_t));
if (ummcf->um_url == NULL) {
return NGX_CONF_ERROR;
}
u = ummcf->um_url;
if (ngx_strncasecmp(url->data, (u_char *)"http://", 7) == 0) {
add = 7;
port = 80;
} else {
return "Invalid args, only support http://";
}
u->url.len = url->len - add;
u->url.data = url->data + add;
u->default_port = port;
u->uri_part = 1;
u->no_resolve = 1;
ummcf->upstream = ngx_stream_upstream_add(cf, u, 0);
if (ummcf->upstream == NULL) {
return NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
static char *
ngx_stream_upstream(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
{
char *rv;
void *mconf;
ngx_str_t *value;
ngx_url_t u;
ngx_uint_t m;
ngx_conf_t pcf;
ngx_stream_module_t *module;
ngx_stream_conf_ctx_t *ctx, *stream_ctx;
ngx_stream_upstream_srv_conf_t *uscf;
ngx_memzero(&u, sizeof(ngx_url_t));
value = cf->args->elts;
u.host = value[1];
u.no_resolve = 1;
u.no_port = 1;
uscf = ngx_stream_upstream_add(cf, &u, NGX_STREAM_UPSTREAM_CREATE
|NGX_STREAM_UPSTREAM_WEIGHT
|NGX_STREAM_UPSTREAM_MAX_FAILS
|NGX_STREAM_UPSTREAM_FAIL_TIMEOUT
|NGX_STREAM_UPSTREAM_DOWN
|NGX_STREAM_UPSTREAM_BACKUP);
if (uscf == NULL) {
return NGX_CONF_ERROR;
}
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_stream_conf_ctx_t));
if (ctx == NULL) {
return NGX_CONF_ERROR;
}
stream_ctx = cf->ctx;
ctx->main_conf = stream_ctx->main_conf;
/* the upstream{}'s srv_conf */
ctx->srv_conf = ngx_pcalloc(cf->pool,
sizeof(void *) * ngx_stream_max_module);
if (ctx->srv_conf == NULL) {
return NGX_CONF_ERROR;
}
ctx->srv_conf[ngx_stream_upstream_module.ctx_index] = uscf;
uscf->srv_conf = ctx->srv_conf;
for (m = 0; ngx_modules[m]; m++) {
if (ngx_modules[m]->type != NGX_STREAM_MODULE) {
continue;
}
module = ngx_modules[m]->ctx;
if (module->create_srv_conf) {
mconf = module->create_srv_conf(cf);
if (mconf == NULL) {
return NGX_CONF_ERROR;
}
ctx->srv_conf[ngx_modules[m]->ctx_index] = mconf;
}
}
uscf->servers = ngx_array_create(cf->pool, 4,
sizeof(ngx_stream_upstream_server_t));
if (uscf->servers == NULL) {
return NGX_CONF_ERROR;
}
/* parse inside upstream{} */
pcf = *cf;
cf->ctx = ctx;
cf->cmd_type = NGX_STREAM_UPS_CONF;
rv = ngx_conf_parse(cf, NULL);
*cf = pcf;
if (rv != NGX_CONF_OK) {
return rv;
}
if (uscf->servers->nelts == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"no servers are inside upstream");
return NGX_CONF_ERROR;
}
return rv;
}
// 解析upstream{}块，它相当于server{}块，级别相同
// 创建一个upstream{}块的配置信息
// 检查是否有同名的upstream{}，如有则报错
// 加入main conf里的upstreams数组，之后就可以在这里找到所有的upstream{}
// 创建数组，存储upstream{}里的服务器信息
// 要求至少有一个server指定上游服务器，否则出错
static char *
ngx_stream_upstream(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
{
char *rv;
void *mconf;
ngx_str_t *value;
ngx_url_t u;
ngx_uint_t m;
ngx_conf_t pcf;
ngx_stream_module_t *module;
ngx_stream_conf_ctx_t *ctx, *stream_ctx;
ngx_stream_upstream_srv_conf_t *uscf;
ngx_memzero(&u, sizeof(ngx_url_t));
value = cf->args->elts;
// 指令的第一个参数是upstream块的名字
u.host = value[1];
u.no_resolve = 1;
u.no_port = 1;
// 创建或者获取一个upstream{}块的配置信息
// 获取时flags==0
// 检查是否有同名的upstream{}，如果是创建时有则报错
// 加入main conf里的upstreams数组，之后就可以在这里找到所有的upstream{}
uscf = ngx_stream_upstream_add(cf, &u, NGX_STREAM_UPSTREAM_CREATE
|NGX_STREAM_UPSTREAM_WEIGHT
|NGX_STREAM_UPSTREAM_MAX_FAILS
|NGX_STREAM_UPSTREAM_FAIL_TIMEOUT
|NGX_STREAM_UPSTREAM_DOWN
|NGX_STREAM_UPSTREAM_BACKUP);
if (uscf == NULL) {
return NGX_CONF_ERROR;
}
// tcp流处理的配置结构体
// 与http不同的是没有location，只有两级
// 在cycle->conf_ctx里存储的是stream{}级别的配置
ctx = ngx_pcalloc(cf->pool, sizeof(ngx_stream_conf_ctx_t));
if (ctx == NULL) {
return NGX_CONF_ERROR;
}
// 保存stream{}的配置上下文
// 也就是stream{}里的ngx_stream_conf_ctx_t
stream_ctx = cf->ctx;
// main_conf直接指向stream{}的main_conf
ctx->main_conf = stream_ctx->main_conf;
/* the upstream{}'s srv_conf */
// 分配存储srv_conf的数组，数量是ngx_stream_max_module
ctx->srv_conf = ngx_pcalloc(cf->pool,
sizeof(void *) * ngx_stream_max_module);
if (ctx->srv_conf == NULL) {
return NGX_CONF_ERROR;
}
// 存储本配置块的配置
// ngx_stream_upstream_module相当于ngx_stream_core_module
// 同时在main conf的servers数组里也有
ctx->srv_conf[ngx_stream_upstream_module.ctx_index] = uscf;
// 保存本upstream{}的配置数组
uscf->srv_conf = ctx->srv_conf;
// 遍历模块数组，调用每个stream模块create_srv_conf，创建配置结构体
// 但实际上除了负载均衡模块，其他模块不会在这里出现，没有意义
for (m = 0; cf->cycle->modules[m]; m++) {
if (cf->cycle->modules[m]->type != NGX_STREAM_MODULE) {
continue;
}
module = cf->cycle->modules[m]->ctx;
if (module->create_srv_conf) {
mconf = module->create_srv_conf(cf);
if (mconf == NULL) {
return NGX_CONF_ERROR;
}
ctx->srv_conf[cf->cycle->modules[m]->ctx_index] = mconf;
}
}
// 创建数组，准备存储upstream{}里的服务器信息
uscf->servers = ngx_array_create(cf->pool, 4,
sizeof(ngx_stream_upstream_server_t));
if (uscf->servers == NULL) {
return NGX_CONF_ERROR;
}
/* parse inside upstream{} */
// 暂存当前的解析上下文
pcf = *cf;
// 设置upstream模块的新解析上下文
// 使用刚才刚创建的配置结构体存储模块的配置信息
cf->ctx = ctx;
cf->cmd_type = NGX_STREAM_UPS_CONF;
// 递归解析事件相关模块
// 里面主要是server指令和负载均衡算法指令
rv = ngx_conf_parse(cf, NULL);
// 恢复之前保存的解析上下文
*cf = pcf;
if (rv != NGX_CONF_OK) {
return rv;
}
// 要求至少有一个server指定上游服务器，否则出错
if (uscf->servers->nelts == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"no servers are inside upstream");
return NGX_CONF_ERROR;
}
return rv;
}
