Re-create the event loop after daemonizing on BSD platforms.

Because kqueue(2) is not inherited by the child process.

Author: Yuichiro NAITO

include/fluent-bit/flb_lib.h

@@ -49,6 +49,8 @@ typedef struct flb_lib_ctx         flb_ctx_t;
 struct flb_processor;
 
 FLB_EXPORT void flb_init_env();
+FLB_EXPORT int flb_create_event_loop(flb_ctx_t *ctx);
+FLB_EXPORT int flb_destroy_event_loop(flb_ctx_t *ctx);
 FLB_EXPORT flb_ctx_t *flb_create();
 FLB_EXPORT void flb_destroy(flb_ctx_t *ctx);
 FLB_EXPORT int flb_input(flb_ctx_t *ctx, const char *input, void *data);

src/flb_lib.c

@@ -140,6 +140,70 @@ void flb_init_env()
     cmt_initialize();
 }
 
+int flb_create_event_loop(flb_ctx_t *ctx)
+{
+    int ret;
+    struct flb_config *config = ctx->config;
+
+    /* Create the event loop to receive notifications */
+    ctx->event_loop = mk_event_loop_create(256);
+    if (!ctx->event_loop) {
+        flb_config_exit(ctx->config);
+        flb_free(ctx);
+        return FLB_LIB_ERROR;
+    }
+    config->ch_evl = ctx->event_loop;
+
+    /* Prepare the notification channels */
+    ctx->event_channel = flb_calloc(1, sizeof(struct mk_event));
+    if (!ctx->event_channel) {
+        perror("calloc");
+        flb_config_exit(ctx->config);
+        flb_free(ctx);
+        return FLB_LIB_ERROR;
+    }
+
+    MK_EVENT_ZERO(ctx->event_channel);
+
+    ret = mk_event_channel_create(config->ch_evl,
+                                  &config->ch_notif[0],
+                                  &config->ch_notif[1],
+                                  ctx->event_channel);
+    if (ret != 0) {
+        flb_error("[lib] could not create notification channels");
+        flb_stop(ctx);
+        flb_destroy(ctx);
+        return FLB_LIB_ERROR;
+    }
+
+    return 0;
+}
+
+int flb_destroy_event_loop(flb_ctx_t *ctx)
+{
+    int ret;
+    struct flb_config *config;
+
+    if (ctx == NULL)
+        return 0;
+
+    config = ctx->config;
+    ret = mk_event_channel_destroy(config->ch_evl,
+                                   config->ch_notif[0],
+                                   config->ch_notif[1],
+                                   ctx->event_channel);
+    if (ret != 0) {
+        /* make sure to close file descriptors */
+        close(config->ch_notif[0]);
+        close(config->ch_notif[1]);
+    }
+
+    free(ctx->event_channel);
+
+    mk_event_loop_destroy(ctx->event_loop);
+    return 0;
+}
+
 flb_ctx_t *flb_create()
 {
     int ret;
@@ -184,36 +248,9 @@ flb_ctx_t *flb_create()
         return NULL;
     }
 
-    /* Create the event loop to receive notifications */
-    ctx->event_loop = mk_event_loop_create(256);
-    if (!ctx->event_loop) {
-        flb_config_exit(ctx->config);
-        flb_free(ctx);
-        return NULL;
-    }
-    config->ch_evl = ctx->event_loop;
-
-    /* Prepare the notification channels */
-    ctx->event_channel = flb_calloc(1, sizeof(struct mk_event));
-    if (!ctx->event_channel) {
-        perror("calloc");
-        flb_config_exit(ctx->config);
-        flb_free(ctx);
-        return NULL;
-    }
-
-    MK_EVENT_ZERO(ctx->event_channel);
-
-    ret = mk_event_channel_create(config->ch_evl,
-                                  &config->ch_notif[0],
-                                  &config->ch_notif[1],
-                                  ctx->event_channel);
-    if (ret != 0) {
-        flb_error("[lib] could not create notification channels");
-        flb_stop(ctx);
-        flb_destroy(ctx);
+    ret = flb_create_event_loop(ctx);
+    if (ret != 0)
         return NULL;
-    }
 
     #ifdef FLB_HAVE_AWS_ERROR_REPORTER
     if (is_error_reporting_enabled()) {

src/fluent-bit.c

@@ -1415,7 +1415,16 @@ static int flb_main_run(int argc, char **argv)
 #ifdef FLB_HAVE_FORK
     /* Run in background/daemon mode */
     if (config->daemon == FLB_TRUE) {
+#if defined(__FreeBSD__) || defined(__NetBSD__) || \
+    defined(__OpenBSD__) || defined(__DragonFly__)
+        flb_destroy_event_loop(ctx);
+#endif
         flb_utils_set_daemon(config);
+#if defined(__FreeBSD__) || defined(__NetBSD__) || \
+    defined(__OpenBSD__) || defined(__DragonFly__)
+        if (flb_create_event_loop(ctx) != 0)
+            flb_utils_error(FLB_ERR_CFG_FLUSH);
+#endif
     }
 #endif