On 06/24/2015 03:35 PM, Michal Židek wrote:

From 145f6b193f5ff9e382af441299864aac55c31dd4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20=C5=BDidek?= <mzidek@redhat.com>
Date: Wed, 17 Jun 2015 18:54:14 +0200
Subject: [PATCH 1/2] MONITOR: Poll for resolv.conf if not available during
 boot

If resolv.conf is not available when SSSD is starting,
check for its existence later.

Ticket:
https://fedorahosted.org/sssd/ticket/2590
---
 src/monitor/monitor.c | 38 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/src/monitor/monitor.c b/src/monitor/monitor.c
index 01c882a..1804ad1 100644
--- a/src/monitor/monitor.c
+++ b/src/monitor/monitor.c
@@ -2259,11 +2259,39 @@ static errno_t monitor_config_file_fallback(TALLOC_CTX *mem_ctx,
     return EOK;
 }
 
+#define MISSING_RESOLV_CONF_POLL_TIME 10
+
+static void missing_resolv_conf(struct tevent_context *ev,
+                                struct tevent_timer *te,
+                                struct timeval tv, void *data)
+{
+    int ret;
+    struct mt_ctx *ctx = talloc_get_type(data, struct mt_ctx);
+
+    ret = monitor_config_file(ctx, ctx, RESOLV_CONF_PATH,
+                              monitor_update_resolv, false);
+    if (ret == EOK) {
+        signal_res_init(ctx);
+    } else if (ret == ENOENT) {
+        tv = tevent_timeval_current_ofs(MISSING_RESOLV_CONF_POLL_TIME, 0);
+        te = tevent_add_timer(ctx->ev, ctx, tv, missing_resolv_conf, ctx);
+        if (te == NULL) {
+            DEBUG(SSSDBG_FATAL_FAILURE,
+                  "tevent_add_timer failed. resolv.conf will be ignored.\n");
+        }
+    } else {
+        DEBUG(SSSDBG_FATAL_FAILURE,
+              "Monitor_config_file failed. resolv.conf will be ignored.\n");
+    }
+}
+
 static int monitor_process_init(struct mt_ctx *ctx,
                                 const char *config_file)
 {
     TALLOC_CTX *tmp_ctx;
     struct tevent_signal *tes;
+    struct timeval tv;
+    struct tevent_timer *te;
     struct sss_domain_info *dom;
     char *rcachedir;
     int num_providers;
@@ -2351,8 +2379,14 @@ static int monitor_process_init(struct mt_ctx *ctx,
 #endif
     /* Watch for changes to the DNS resolv.conf */
Michal would you consider renaming 'missing_resolv_conf' to 'check_resolv_conf' or something like that and  then replace following code segment by simple call of it? I think we could save a few lines of code and reuse the function.  Do you see any problems about that? Thanks!
     ret = monitor_config_file(ctx, ctx, RESOLV_CONF_PATH,
-                             monitor_update_resolv,true);
-    if (ret != EOK) {
+                              monitor_update_resolv, false);
+    if (ret == ENOENT) {
+        tv = tevent_timeval_current_ofs(MISSING_RESOLV_CONF_POLL_TIME, 0);
+        te = tevent_add_timer(ctx->ev, ctx, tv, missing_resolv_conf, ctx);
+        if (te == NULL) {
+            DEBUG(SSSDBG_FATAL_FAILURE, "resolv.conf will be ignored\n");
+        }
+    } else if (ret != EOK) {
         return ret;
     }
 
-- 2.1.0