build: utils: detect fork(2) support / enable/disable daemon mode

Signed-off-by: Eduardo Silva <[email protected]>

CMakeLists.txt

@@ -271,6 +271,18 @@ if(FLB_VALGRIND OR FLB_HAVE_VALGRIND)
  FLB_DEFINITION(FLB_HAVE_VALGRIND)
 endif()
 
+# fork(2) support
+check_c_source_compiles("
+ #include <unistd.h>
+ int main() {
+ fork();
+ return 0;
+ }" FLB_HAVE_FORK)
+
+if(FLB_HAVE_FORK)
+ FLB_DEFINITION(FLB_HAVE_FORK)
+endif()
+
 # mtrace support
 if(FLB_MTRACE)
  check_c_source_compiles("

include/fluent-bit/flb_utils.h

@@ -20,6 +20,7 @@
 #ifndef FLB_UTILS_H
 #define FLB_UTILS_H
 
+#include <fluent-bit/flb_info.h>
 #include <fluent-bit/flb_config.h>
 
 struct flb_split_entry {
@@ -32,7 +33,11 @@ void flb_utils_error(int err);
 void flb_utils_error_c(const char *msg);
 void flb_utils_warn_c(const char *msg);
 void flb_message(int type, char *file, int line, const char *fmt, ...);
+
+#ifdef FLB_HAVE_FORK
 int flb_utils_set_daemon();
+#endif
+
 void flb_utils_print_setup(struct flb_config *config);
 
 struct mk_list *flb_utils_split(char *line, int separator);

src/flb_utils.c

@@ -21,7 +21,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
-#include <sys/time.h>
+
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <msgpack.h>
@@ -112,6 +112,7 @@ void flb_utils_warn_c(const char *msg)
  ANSI_BOLD ANSI_YELLOW, ANSI_RESET, msg);
 }
 
+#ifdef FLB_HAVE_FORK
 /* Run current process in background mode */
 int flb_utils_set_daemon(struct flb_config *config)
 {
@@ -145,6 +146,7 @@ int flb_utils_set_daemon(struct flb_config *config)
 
  return 0;
 }
+#endif
 
 void flb_utils_print_setup(struct flb_config *config)
 {

src/fluent-bit.c

@@ -65,7 +65,9 @@ static void flb_help(int rc, struct flb_config *config)
  printf(" -B --buf_workers=N\tnumber of workers for buffering\n");
 #endif
  printf(" -c --config=FILE\tspecify an optional configuration file\n");
+#ifdef FLB_HAVE_FORK
  printf(" -d, --daemon\t\trun Fluent Bit in background mode\n");
+#endif
  printf(" -f, --flush=SECONDS\tflush timeout in seconds (default: %i)\n",
  FLB_CONFIG_FLUSH_SECS);
  printf(" -i, --input=INPUT\tset an input\n");
@@ -333,7 +335,9 @@ int main(int argc, char **argv)
  { "buf_path", required_argument, NULL, 'b' },
  { "buf_workers", required_argument, NULL, 'B' },
  { "config", required_argument, NULL, 'c' },
+#ifdef FLB_HAVE_FORK
  { "daemon", no_argument , NULL, 'd' },
+#endif
  { "flush", required_argument, NULL, 'f' },
  { "http", no_argument , NULL, 'H' },
  { "logfile", required_argument, NULL, 'l' },
@@ -387,9 +391,11 @@ int main(int argc, char **argv)
  case 'c':
  cfg_file = flb_strdup(optarg);
  break;
+#ifdef FLB_HAVE_FORK
  case 'd':
  config->daemon = FLB_TRUE;
  break;
+#endif
  case 'e':
  if (!flb_plugin_proxy_create(optarg, 0, config)) {
  exit(EXIT_FAILURE);
@@ -501,10 +507,12 @@ int main(int argc, char **argv)
  flb_utils_print_setup(config);
  }
 
+#ifdef FLB_HAVE_FORK
  /* Run in background/daemon mode */
  if (config->daemon == FLB_TRUE) {
  flb_utils_set_daemon(config);
  }
+#endif
 
  flb_engine_start(config);
  return 0;