nghttpx: Add $pid to --accesslog-format variable

$pid refers to the PID of the running process.

src/shrpx.cc

@@ -759,6 +759,7 @@ void fill_default_config()
   mod_config()->pid_file = nullptr;
   mod_config()->uid = 0;
   mod_config()->gid = 0;
+  mod_config()->pid = getpid();
   mod_config()->backend_ipv4 = false;
   mod_config()->backend_ipv6 = false;
   mod_config()->cert_tree = nullptr;
@@ -1142,6 +1143,7 @@ Logging:
                      $server_port: server port.
                      $request_time:   request  processing   time  in
                      seconds with milliseconds resolution.
+                     $pid: PID of the running process.
                      Default: )"
       << DEFAULT_ACCESSLOG_FORMAT << R"(
   --errorlog-file=<PATH>

src/shrpx_client_handler.cc

@@ -746,7 +746,8 @@ void ClientHandler::write_accesslog(Downstream *downstream)
     downstream->get_response_http_status(),
     downstream->get_response_sent_bodylen(),
     port_.c_str(),
-    get_config()->port
+    get_config()->port,
+    get_config()->pid,
   };
 
   upstream_accesslog(get_config()->accesslog_format, &lgsp);
@@ -767,7 +768,8 @@ void ClientHandler::write_accesslog(int major, int minor,
     status,
     body_bytes_sent,
     port_.c_str(),
-    get_config()->port
+    get_config()->port,
+    get_config()->pid,
   };
 
   upstream_accesslog(get_config()->accesslog_format, &lgsp);

src/shrpx_config.cc

@@ -402,6 +402,8 @@ std::vector<LogFragment> parse_log_format(const char *optarg)
       type = SHRPX_LOGF_SERVER_PORT;
     } else if(util::strieq("$request_time", var_start, varlen)) {
       type = SHRPX_LOGF_REQUEST_TIME;
+    } else if(util::strieq("$pid", var_start, varlen)) {
+      type = SHRPX_LOGF_PID;
     } else {
       LOG(WARN) << "Unrecognized log format variable: "
                 << std::string(var_start, varlen);

src/shrpx_config.h

@@ -254,6 +254,7 @@ struct Config {
   int argc;
   uid_t uid;
   gid_t gid;
+  pid_t pid;
   uint16_t port;
   uint16_t downstream_port;
   // port in http proxy URI

src/shrpx_log.cc

@@ -139,7 +139,7 @@ Log::~Log()
     rv = snprintf(buf, sizeof(buf),
                   "%s PID%d [%s%s%s] %s\n",
                   cached_time->c_str(),
-                  getpid(),
+                  get_config()->pid,
                   tty ? SEVERITY_COLOR[severity_] : "",
                   SEVERITY_STR[severity_],
                   tty ? "\033[0m" : "",
@@ -148,7 +148,7 @@ Log::~Log()
     rv = snprintf(buf, sizeof(buf),
                   "%s PID%d [%s%s%s] %s%s:%d%s %s\n",
                   cached_time->c_str(),
-                  getpid(),
+                  get_config()->pid,
                   tty ? SEVERITY_COLOR[severity_] : "",
                   SEVERITY_STR[severity_],
                   tty ? "\033[0m" : "",
@@ -258,6 +258,9 @@ void upstream_accesslog(const std::vector<LogFragment>& lfv, LogSpec *lgsp)
         std::tie(p, avail) = copy( sec.c_str(), avail, p);
       }
       break;
+    case SHRPX_LOGF_PID:
+      std::tie(p, avail) = copy(util::utos(lgsp->pid).c_str(), avail, p);
+      break;
     case SHRPX_LOGF_NONE:
       break;
     default:

src/shrpx_log.h

@@ -27,6 +27,8 @@
 
 #include "shrpx.h"
 
+#include <sys/types.h>
+
 #include <sstream>
 #include <memory>
 #include <vector>
@@ -116,6 +118,7 @@ enum LogFragmentType {
   SHRPX_LOGF_REMOTE_PORT,
   SHRPX_LOGF_SERVER_PORT,
   SHRPX_LOGF_REQUEST_TIME,
+  SHRPX_LOGF_PID,
 };
 
 struct LogFragment {
@@ -135,6 +138,7 @@ struct LogSpec {
   int64_t body_bytes_sent;
   const char *remote_port;
   uint16_t server_port;
+  pid_t pid;
 };
 
 void upstream_accesslog(const std::vector<LogFragment>& lf, LogSpec *lgsp);