nginx-otel-nix/src/http_module.cpp
2023-06-13 16:59:02 -07:00

876 lines
22 KiB
C++

extern "C" {
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
}
#include <grpc/support/log.h>
#include <google/protobuf/stubs/logging.h>
#include "str_view.hpp"
#include "trace_context.hpp"
#include "batch_exporter.hpp"
extern ngx_module_t gHttpModule;
namespace {
struct OtelCtx {
TraceContext parent;
TraceContext current;
};
struct MainConf {
ngx_str_t endpoint;
ngx_msec_t interval;
size_t batchSize;
size_t batchCount;
ngx_str_t serviceName;
};
struct SpanAttr {
ngx_str_t name;
ngx_http_complex_value_t value;
};
struct LocationConf {
ngx_http_complex_value_t* trace;
ngx_uint_t traceContext;
ngx_http_complex_value_t* spanName;
ngx_array_t spanAttrs;
};
char* setExporter(ngx_conf_t* cf, ngx_command_t* cmd, void* conf);
char* addSpanAttr(ngx_conf_t* cf, ngx_command_t* cmd, void* conf);
namespace Propagation {
const ngx_uint_t Extract = 1;
const ngx_uint_t Inject = 2;
/*const*/ ngx_conf_enum_t Types[] = {
{ ngx_string("ignore"), 0 },
{ ngx_string("extract"), Extract },
{ ngx_string("inject"), Inject },
{ ngx_string("propagate"), Extract | Inject },
{ ngx_null_string, 0 }
};
}
ngx_command_t gCommands[] = {
{ ngx_string("otel_exporter"),
NGX_HTTP_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_NOARGS,
setExporter,
NGX_HTTP_MAIN_CONF_OFFSET },
{ ngx_string("otel_service_name"),
NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
ngx_conf_set_str_slot,
NGX_HTTP_MAIN_CONF_OFFSET,
offsetof(MainConf, serviceName) },
{ ngx_string("otel_trace"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_http_set_complex_value_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(LocationConf, trace) },
{ ngx_string("otel_trace_context"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_conf_set_enum_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(LocationConf, traceContext),
&Propagation::Types },
{ ngx_string("otel_span_name"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_http_set_complex_value_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(LocationConf, spanName) },
{ ngx_string("otel_span_attr"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
addSpanAttr,
NGX_HTTP_LOC_CONF_OFFSET },
ngx_null_command
};
ngx_command_t gExporterCommands[] = {
{ ngx_string("endpoint"),
NGX_CONF_TAKE1,
ngx_conf_set_str_slot,
0,
offsetof(MainConf, endpoint) },
{ ngx_string("interval"),
NGX_CONF_TAKE1,
ngx_conf_set_msec_slot,
0,
offsetof(MainConf, interval) },
{ ngx_string("batch_size"),
NGX_CONF_TAKE1,
ngx_conf_set_size_slot,
0,
offsetof(MainConf, batchSize) },
{ ngx_string("batch_count"),
NGX_CONF_TAKE1,
ngx_conf_set_size_slot,
0,
offsetof(MainConf, batchCount) },
ngx_null_command
};
std::unique_ptr<BatchExporter> gExporter;
StrView toStrView(ngx_str_t str)
{
return StrView((char*)str.data, str.len);
}
ngx_str_t toNgxStr(StrView str)
{
return ngx_str_t{str.size(), (u_char*)str.data()};
}
LocationConf* getLocationConf(ngx_http_request_t* r)
{
return (LocationConf*)ngx_http_get_module_loc_conf(r, gHttpModule);
}
void cleanupOtelCtx(void* data)
{
}
OtelCtx* getOtelCtx(ngx_http_request_t* r)
{
auto ctx = (OtelCtx*)ngx_http_get_module_ctx(r, gHttpModule);
// restore module context if it was reset by e.g. internal redirect
if (ctx == NULL && (r->internal || r->filter_finalize)) {
for (auto cln = r->pool->cleanup; cln; cln = cln->next) {
if (cln->handler == cleanupOtelCtx) {
ctx = (OtelCtx*)cln->data;
ngx_http_set_ctx(r, ctx, gHttpModule);
break;
}
}
}
return ctx;
}
OtelCtx* createOtelCtx(ngx_http_request_t* r)
{
static_assert(std::is_trivially_destructible<OtelCtx>::value, "");
auto storage = ngx_pool_cleanup_add(r->pool, sizeof(OtelCtx));
if (storage == NULL) {
return NULL;
}
storage->handler = cleanupOtelCtx;
auto ctx = new (storage->data) OtelCtx{};
ngx_http_set_ctx(r, ctx, gHttpModule);
return ctx;
}
ngx_table_elt_t* findHeader(ngx_list_t* list, ngx_uint_t hash, StrView key)
{
auto part = &list->part;
auto elts = (ngx_table_elt_t*)part->elts;
for (ngx_uint_t i = 0; /* void */; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
elts = (ngx_table_elt_t*)part->elts;
i = 0;
}
if (elts[i].hash != hash || elts[i].key.len != key.size() ||
ngx_memcmp(elts[i].lowcase_key, key.data(), key.size()) != 0) {
continue;
}
return &elts[i];
}
return NULL;
}
StrView getHeader(ngx_http_request_t* r, StrView name)
{
auto hash = ngx_hash_key((u_char*)name.data(), name.size());
auto header = findHeader(&r->headers_in.headers, hash, name);
return header ? toStrView(header->value) : StrView{};
}
ngx_int_t updateRequestHeader(ngx_http_request_t* r, ngx_table_elt_t* header)
{
auto cmcf = (ngx_http_core_main_conf_t*)
ngx_http_get_module_main_conf(r, ngx_http_core_module);
auto hh = (ngx_http_header_t*)ngx_hash_find(&cmcf->headers_in_hash,
header->hash, header->lowcase_key, header->key.len);
return hh ? hh->handler(r, header, hh->offset) : NGX_OK;
}
ngx_int_t setHeader(ngx_http_request_t* r, StrView name, StrView value)
{
auto hash = ngx_hash_key((u_char*)name.data(), name.size());
auto header = findHeader(&r->headers_in.headers, hash, name);
if (header == NULL) {
if (value.empty()) {
return NGX_OK;
}
header = (ngx_table_elt_t*)ngx_list_push(&r->headers_in.headers);
if (header == NULL) {
return NGX_ERROR;
}
header->hash = hash;
header->key = toNgxStr(name);
header->lowcase_key = header->key.data;
header->next = NULL;
}
header->value = toNgxStr(value);
return updateRequestHeader(r, header);
}
TraceContext extract(ngx_http_request_t* r)
{
auto parent = getHeader(r, "traceparent");
auto state = getHeader(r, "tracestate");
return TraceContext::parse(parent, state);
}
ngx_int_t inject(ngx_http_request_t* r, const TraceContext& tc)
{
auto buf = (char*)ngx_pnalloc(r->pool, TraceContext::Size);
if (buf == NULL) {
return NGX_ERROR;
}
TraceContext::serialize(tc, buf);
auto rc = setHeader(r, "traceparent", {buf, TraceContext::Size});
if (rc != NGX_OK) {
return rc;
}
return setHeader(r, "tracestate", tc.state);
}
OtelCtx* ensureOtelCtx(ngx_http_request_t* r)
{
auto ctx = getOtelCtx(r);
if (ctx) {
return ctx;
}
ctx = createOtelCtx(r);
if (!ctx) {
return NULL;
}
auto lcf = getLocationConf(r);
if (lcf->traceContext & Propagation::Extract) {
ctx->parent = extract(r);
}
ctx->current = TraceContext::generate(false, ctx->parent);
return ctx;
}
ngx_int_t onRequestStart(ngx_http_request_t* r)
{
// don't let internal redirects to override sampling decision
if (r->internal) {
return NGX_DECLINED;
}
bool sampled = false;
auto lcf = getLocationConf(r);
if (lcf->trace != NULL) {
ngx_str_t trace;
if (ngx_http_complex_value(r, lcf->trace, &trace) != NGX_OK) {
return NGX_ERROR;
}
sampled = toStrView(trace) == "on" || toStrView(trace) == "1";
}
if (!lcf->traceContext && !sampled) {
return NGX_DECLINED;
}
auto ctx = ensureOtelCtx(r);
if (!ctx) {
return NGX_ERROR;
}
ctx->current.sampled = sampled;
ngx_int_t rc = NGX_OK;
if (lcf->traceContext & Propagation::Inject) {
rc = inject(r, ctx->current);
}
return rc == NGX_OK ? NGX_DECLINED : rc;
}
StrView getServerName(ngx_http_request_t* r)
{
auto cscf = (ngx_http_core_srv_conf_t*)
ngx_http_get_module_srv_conf(r, ngx_http_core_module);
auto name = cscf->server_name;
if (name.len == 0) {
name = r->headers_in.server;
}
return toStrView(name);
}
void addDefaultAttrs(BatchExporter::Span& span, ngx_http_request_t* r)
{
// based on trace semantic conventions for HTTP from 1.16.0 OTel spec
span.add("http.method", toStrView(r->method_name));
span.add("http.target", toStrView(r->unparsed_uri));
auto clcf = (ngx_http_core_loc_conf_t*)
ngx_http_get_module_loc_conf(r, ngx_http_core_module);
if (clcf->name.len) {
span.add("http.route", toStrView(clcf->name));
}
span.add("http.scheme", r->connection->ssl ? "https" : "http");
auto protocol = toStrView(r->http_protocol);
if (protocol.size() > 5) { // "HTTP/"
span.add("http.flavor", protocol.substr(5));
}
if (r->headers_in.user_agent) {
span.add("http.user_agent", toStrView(r->headers_in.user_agent->value));
}
auto received = r->headers_in.content_length_n;
span.add("http.request_content_length", received > 0 ? received : 0);
auto sent = r->connection->sent - (off_t)r->header_size;
span.add("http.response_content_length", sent > 0 ? sent : 0);
auto status = r->err_status ? r->err_status : r->headers_out.status;
if (status) {
span.add("http.status_code", status);
if (status >= 500) {
span.setError();
}
}
span.add("net.host.name", getServerName(r));
if (ngx_connection_local_sockaddr(r->connection, NULL, 0) == NGX_OK) {
auto port = ngx_inet_get_port(r->connection->local_sockaddr);
auto defaultPort = r->connection->ssl ? 443 : 80;
if (port != defaultPort) {
span.add("net.host.port", port);
}
}
span.add("net.sock.peer.addr", toStrView(r->connection->addr_text));
span.add("net.sock.peer.port", ngx_inet_get_port(r->connection->sockaddr));
}
StrView getSpanName(ngx_http_request_t* r)
{
auto lcf = getLocationConf(r);
if (lcf->spanName) {
ngx_str_t result;
if (ngx_http_complex_value(r, lcf->spanName, &result) != NGX_OK) {
throw std::runtime_error("failed to compute complex value");
}
return toStrView(result);
} else {
auto clcf = (ngx_http_core_loc_conf_t*)
ngx_http_get_module_loc_conf(r, ngx_http_core_module);
return toStrView(clcf->name);
}
}
void addCustomAttrs(BatchExporter::Span& span, ngx_http_request_t* r)
{
auto lcf = getLocationConf(r);
auto attrs = (SpanAttr*)lcf->spanAttrs.elts;
for (ngx_uint_t i = 0; i < lcf->spanAttrs.nelts; i++) {
ngx_str_t value;
if (ngx_http_complex_value(r, &attrs[i].value, &value) != NGX_OK) {
throw std::runtime_error("failed to compute complex value");
}
StrView name = toStrView(attrs[i].name);
if (startsWith(name, "http.request.header.") ||
startsWith(name, "http.response.header."))
{
//TODO: remove this once headers are supported natively
span.addArray(name, toStrView(value));
} else {
span.add(name, toStrView(value));
}
}
}
ngx_int_t onRequestEnd(ngx_http_request_t* r)
{
auto ctx = getOtelCtx(r);
if (!ctx || !ctx->current.sampled) {
return NGX_DECLINED;
}
auto now = ngx_timeofday();
auto toNanoSec = [](time_t sec, ngx_msec_t msec) -> uint64_t {
return (sec * 1000 + msec) * 1000000;
};
try {
BatchExporter::SpanInfo info{
getSpanName(r), ctx->current, ctx->parent.spanId,
toNanoSec(r->start_sec, r->start_msec),
toNanoSec(now->sec, now->msec)};
bool ok = gExporter->add(info, [r](BatchExporter::Span& span) {
addDefaultAttrs(span, r);
addCustomAttrs(span, r);
});
if (!ok) {
static size_t dropped = 0;
static time_t lastLog = 0;
++dropped;
if (lastLog != ngx_time()) {
lastLog = ngx_time();
ngx_log_error(NGX_LOG_NOTICE, r->connection->log, 0,
"OTel dropped records: %uz", dropped);
}
}
} catch (const std::exception& e) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"OTel failed to add span: %s", e.what());
return NGX_ERROR;
}
return NGX_DECLINED;
}
void grpcLogHandler(gpr_log_func_args* args)
{
ngx_uint_t level = args->severity == GPR_LOG_SEVERITY_ERROR ? NGX_LOG_ERR :
args->severity == GPR_LOG_SEVERITY_INFO ? NGX_LOG_INFO :
/*GPR_LOG_SEVERITY_DEBUG*/ NGX_LOG_DEBUG;
ngx_log_error(level, ngx_cycle->log, 0, "OTel/grpc: %s", args->message);
}
void protobufLogHandler(google::protobuf::LogLevel logLevel,
const char* filename, int line, const std::string& msg)
{
using namespace google::protobuf;
ngx_uint_t level = logLevel == LOGLEVEL_FATAL ? NGX_LOG_EMERG :
logLevel == LOGLEVEL_ERROR ? NGX_LOG_ERR :
logLevel == LOGLEVEL_WARNING ? NGX_LOG_WARN :
/*LOGLEVEL_INFO*/ NGX_LOG_INFO;
ngx_log_error(level, ngx_cycle->log, 0, "OTel/protobuf: %s", msg.c_str());
}
ngx_int_t initModule(ngx_conf_t* cf)
{
auto cmcf = (ngx_http_core_main_conf_t*)ngx_http_conf_get_module_main_conf(
cf, ngx_http_core_module);
auto h = (ngx_http_handler_pt*)ngx_array_push(
&cmcf->phases[NGX_HTTP_REWRITE_PHASE].handlers);
if (h == NULL) {
return NGX_ERROR;
}
*h = onRequestStart;
h = (ngx_http_handler_pt*)ngx_array_push(
&cmcf->phases[NGX_HTTP_LOG_PHASE].handlers);
if (h == NULL) {
return NGX_ERROR;
}
*h = onRequestEnd;
gpr_set_log_function(grpcLogHandler);
google::protobuf::SetLogHandler(protobufLogHandler);
return NGX_OK;
}
ngx_int_t initWorkerProcess(ngx_cycle_t* cycle)
{
auto mcf = (MainConf*)ngx_http_cycle_get_module_main_conf(
cycle, gHttpModule);
// no 'http' or 'otel_exporter' blocks
if (mcf == NULL || mcf->endpoint.len == 0) {
return NGX_OK;
}
try {
gExporter.reset(new BatchExporter(
toStrView(mcf->endpoint),
mcf->batchSize,
mcf->batchCount,
toStrView(mcf->serviceName)));
} catch (const std::exception& e) {
ngx_log_error(NGX_LOG_CRIT, cycle->log, 0,
"OTel worker init error: %s", e.what());
return NGX_ERROR;
}
static ngx_connection_t dummy;
static ngx_event_t flushEvent;
flushEvent.data = &dummy;
flushEvent.log = cycle->log;
flushEvent.cancelable = 1;
flushEvent.handler = [](ngx_event_t* ev) {
try {
gExporter->flush();
} catch (const std::exception& e) {
ngx_log_error(NGX_LOG_CRIT, ev->log, 0,
"OTel flush error: %s", e.what());
}
auto mcf = (MainConf*)ngx_http_cycle_get_module_main_conf(
ngx_cycle, gHttpModule);
ngx_add_timer(ev, mcf->interval);
};
ngx_add_timer(&flushEvent, mcf->interval);
return NGX_OK;
}
void exitWorkerProcess(ngx_cycle_t* cycle)
{
if (!gExporter) {
return;
}
try {
gExporter->flush();
} catch (const std::exception& e) {
ngx_log_error(NGX_LOG_CRIT, cycle->log, 0,
"OTel flush error: %s", e.what());
}
gExporter.reset();
}
char* setExporter(ngx_conf_t* cf, ngx_command_t* cmd, void* conf)
{
auto mcf = (MainConf*)conf;
if (mcf->endpoint.len) {
return (char*)"is duplicate";
}
auto cfCopy = *cf;
cfCopy.handler = [](ngx_conf_t* cf, ngx_command_t*, void*) {
auto name = (ngx_str_t*)cf->args->elts;
for (auto cmd = gExporterCommands; cmd->name.len; cmd++) {
if (ngx_strcmp(name->data, cmd->name.data) != 0) {
continue;
}
if (cf->args->nelts != 2) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"invalid number of arguments in \"%V\" "
"directive of \"otel_exporter\"", name);
return (char*)NGX_CONF_ERROR;
}
auto rv = cmd->set(cf, cmd, cf->handler_conf);
if (rv == NGX_CONF_OK) {
return rv;
}
if (rv != NGX_CONF_ERROR) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"\"%V\" directive of \"otel_exporter\" %s", name, rv);
}
return (char*)NGX_CONF_ERROR;
}
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"unknown directive \"%V\" in \"otel_exporter\"", name);
return (char*)NGX_CONF_ERROR;
};
cfCopy.handler_conf = mcf;
auto rv = ngx_conf_parse(&cfCopy, NULL);
if (rv != NGX_CONF_OK) {
return rv;
}
if (mcf->endpoint.len == 0) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"\"otel_exporter\" requires \"endpoint\"");
return (char*)NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
void* createMainConf(ngx_conf_t* cf)
{
auto mcf = (MainConf*)ngx_pcalloc(cf->pool, sizeof(MainConf));
if (mcf == NULL) {
return NULL;
}
mcf->interval = NGX_CONF_UNSET_MSEC;
mcf->batchSize = NGX_CONF_UNSET_SIZE;
mcf->batchCount = NGX_CONF_UNSET_SIZE;
return mcf;
}
char* initMainConf(ngx_conf_t* cf, void* conf)
{
auto mcf = (MainConf*)conf;
ngx_conf_init_msec_value(mcf->interval, 5000);
ngx_conf_init_size_value(mcf->batchSize, 512);
ngx_conf_init_size_value(mcf->batchCount, 4);
if (mcf->serviceName.data == NULL) {
mcf->serviceName = ngx_string("unknown_service:nginx");
}
return NGX_CONF_OK;
}
char* addSpanAttr(ngx_conf_t* cf, ngx_command_t* cmd, void* conf)
{
auto lcf = (LocationConf*)conf;
if (lcf->spanAttrs.elts == NULL && ngx_array_init(&lcf->spanAttrs,
cf->pool, 4, sizeof(SpanAttr)) != NGX_OK) {
return (char*)NGX_CONF_ERROR;
}
auto attr = (SpanAttr*)ngx_array_push(&lcf->spanAttrs);
if (attr == NULL) {
return (char*)NGX_CONF_ERROR;
}
auto args = (ngx_str_t*)cf->args->elts;
attr->name = args[1];
ngx_http_compile_complex_value_t ccv = { cf, &args[2], &attr->value };
if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
return (char*)NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
template <class Id>
ngx_int_t hexIdVar(ngx_http_request_t* r, ngx_http_variable_value_t* v,
uintptr_t data)
{
auto ctx = ensureOtelCtx(r);
if (!ctx) {
return NGX_ERROR;
}
auto id = (Id*)((char*)ctx + data);
if (id->IsValid()) {
auto size = id->Id().size() * 2;
auto buf = (char*)ngx_pnalloc(r->pool, size);
if (buf == NULL) {
return NGX_ERROR;
}
id->ToLowerBase16({buf, size});
v->len = size;
v->valid = 1;
v->no_cacheable = 0;
v->not_found = 0;
v->data = (u_char*)buf;
} else {
v->not_found = 1;
}
return NGX_OK;
}
ngx_int_t parentSampledVar(ngx_http_request_t* r, ngx_http_variable_value_t* v,
uintptr_t data)
{
auto ctx = ensureOtelCtx(r);
if (!ctx) {
return NGX_ERROR;
}
v->len = 1;
v->valid = 1;
v->no_cacheable = 0;
v->not_found = 0;
v->data = (u_char*)(ctx->parent.sampled ? "1" : "0");
return NGX_OK;
}
ngx_int_t addVariables(ngx_conf_t* cf)
{
using namespace opentelemetry::trace;
ngx_http_variable_t vars[] = {
{ ngx_string("otel_trace_id"), NULL, hexIdVar<TraceId>,
offsetof(OtelCtx, current.traceId) },
{ ngx_string("otel_span_id"), NULL, hexIdVar<SpanId>,
offsetof(OtelCtx, current.spanId) },
{ ngx_string("otel_parent_id"), NULL, hexIdVar<SpanId>,
offsetof(OtelCtx, parent.spanId) },
{ ngx_string("otel_parent_sampled"), NULL, parentSampledVar }
};
for (auto& v : vars) {
auto var = ngx_http_add_variable(cf, &v.name, 0);
if (var == NULL) {
return NGX_ERROR;
}
var->get_handler = v.get_handler;
var->data = v.data;
}
return NGX_OK;
}
void* createLocationConf(ngx_conf_t* cf)
{
auto conf = (LocationConf*)ngx_pcalloc(cf->pool, sizeof(LocationConf));
if (conf == NULL) {
return NULL;
}
conf->trace = (ngx_http_complex_value_t*)NGX_CONF_UNSET_PTR;
conf->traceContext = NGX_CONF_UNSET_UINT;
conf->spanName = (ngx_http_complex_value_t*)NGX_CONF_UNSET_PTR;
return conf;
}
char* mergeLocationConf(ngx_conf_t* cf, void* parent, void* child)
{
auto prev = (LocationConf*)parent;
auto conf = (LocationConf*)child;
ngx_conf_merge_ptr_value(conf->trace, prev->trace, NULL);
ngx_conf_merge_uint_value(conf->traceContext, prev->traceContext, 0);
ngx_conf_merge_ptr_value(conf->spanName, prev->spanName, NULL);
if (conf->spanAttrs.elts == NULL) {
conf->spanAttrs = prev->spanAttrs;
}
auto mcf = (MainConf*)ngx_http_conf_get_module_main_conf(cf, gHttpModule);
if (mcf->endpoint.len == 0 && conf->trace) {
ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
"\"otel_exporter\" block is missing");
return (char*)NGX_CONF_ERROR;
}
return NGX_CONF_OK;
}
ngx_http_module_t gHttpModuleCtx = {
addVariables, /* preconfiguration */
initModule, /* postconfiguration */
createMainConf, /* create main configuration */
initMainConf, /* init main configuration */
NULL, /* create server configuration */
NULL, /* merge server configuration */
createLocationConf, /* create location configuration */
mergeLocationConf /* merge location configuration */
};
}
ngx_module_t gHttpModule = {
NGX_MODULE_V1,
&gHttpModuleCtx, /* module context */
gCommands, /* module directives */
NGX_HTTP_MODULE, /* module type */
NULL, /* init master */
NULL, /* init module */
initWorkerProcess, /* init process */
NULL, /* init thread */
NULL, /* exit thread */
exitWorkerProcess, /* exit process */
NULL, /* exit master */
NGX_MODULE_V1_PADDING
};