director: Log vhost count changes and HOST-UP/DOWN

src/director/director-connection.c

@@ -1012,8 +1012,10 @@ director_cmd_host_int(struct director_connection *conn, const char *const *args,
 	}
 
 	if (update) {
-		mail_host_set_down(host, down, last_updown_change);
-		mail_host_set_vhost_count(host, vhost_count);
+		const char *log_prefix = t_strdup_printf("director(%s): ",
+							 conn->name);
+		mail_host_set_down(host, down, last_updown_change, log_prefix);
+		mail_host_set_vhost_count(host, vhost_count, log_prefix);
 		director_update_host(conn->dir, src_host, dir_host, host);
 	} else {
 		dir_debug("Ignoring host %s update vhost_count=%u "

src/director/doveadm-connection.c

@@ -305,7 +305,7 @@ doveadm_cmd_host_set_or_update(struct doveadm_connection *conn,
 		return 1;
 	}
 	if (vhost_count != UINT_MAX)
-		mail_host_set_vhost_count(host, vhost_count);
+		mail_host_set_vhost_count(host, vhost_count, "doveadm: ");
 	/* NOTE: we don't support changing a tag for an existing host.
 	   it needs to be removed first. otherwise it would be a bit ugly to
 	   handle. */
@@ -352,7 +352,7 @@ doveadm_cmd_host_updown(struct doveadm_connection *conn, bool down,
 			"host is already being updated - try again later\n");
 		return 1;
 	} else {
-		mail_host_set_down(host, down, ioloop_time);
+		mail_host_set_down(host, down, ioloop_time, "doveadm: ");
 		director_update_host(conn->dir, conn->dir->self_host,
 				     NULL, host);
 	}

src/director/mail-host.c

@@ -356,17 +356,29 @@ void mail_host_set_tag(struct mail_host *host, const char *tag_name)
 	host->list->vhosts_unsorted = TRUE;
 }
 
-void mail_host_set_down(struct mail_host *host, bool down, time_t timestamp)
+void mail_host_set_down(struct mail_host *host, bool down,
+			time_t timestamp, const char *log_prefix)
 {
 	if (host->down != down) {
+		const char *updown = down ? "down" : "up";
+		i_info("%sHost %s changed %s "
+		       "(vhost_count=%u last_updown_change=%ld)",
+		       log_prefix, net_ip2addr(&host->ip), updown,
+		       host->vhost_count, (long)host->last_updown_change);
+
 		host->down = down;
 		host->last_updown_change = timestamp;
 		host->list->vhosts_unsorted = TRUE;
 	}
 }
 
-void mail_host_set_vhost_count(struct mail_host *host, unsigned int vhost_count)
+void mail_host_set_vhost_count(struct mail_host *host, unsigned int vhost_count,
+			       const char *log_prefix)
 {
+	i_info("%sHost %s vhost count changed from %u to %u",
+	       log_prefix, net_ip2addr(&host->ip),
+	       host->vhost_count, vhost_count);
+
 	host->vhost_count = vhost_count;
 	host->list->vhosts_unsorted = TRUE;
 }

src/director/mail-host.h

@@ -57,9 +57,10 @@ int mail_hosts_parse_and_add(struct mail_host_list *list,
 			     const char *hosts_string);
 const char *mail_host_get_tag(const struct mail_host *host);
 void mail_host_set_tag(struct mail_host *host, const char *tag_name);
-void mail_host_set_down(struct mail_host *host, bool down, time_t timestamp);
-void mail_host_set_vhost_count(struct mail_host *host,
-			       unsigned int vhost_count);
+void mail_host_set_down(struct mail_host *host, bool down, time_t timestamp,
+			const char *log_prefix);
+void mail_host_set_vhost_count(struct mail_host *host, unsigned int vhost_count,
+			       const char *log_prefix);
 void mail_host_remove(struct mail_host *host);
 
 void mail_hosts_set_synced(struct mail_host_list *list);