collectd: The new `FQDNLookup' option controls whether or not the FQDN should be...

So far the hostname as returned by `gethostname(2)' was used. This is not
practical for large setups.

To stay backwards compatible the option is disabled by default, but the sample
config file includes a line which sets this option so that (new) default
installations will have it enabled.

diff --git a/src/collectd.c b/src/collectd.c
index 4e18fd6..70223b7 100644 (file)
--- a/src/collectd.c
+++ b/src/collectd.c
@@ -23,6 +23,10 @@
 #include "collectd.h"
 #include "common.h"
 
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+
 #include "plugin.h"
 #include "configfile.h"
 #include "types_list.h"
@@ -48,25 +52,63 @@ static void sigTermHandler (int signal)
        loop++;
 }
 
-static int init_global_variables (void)
+static int init_hostname (void)
 {
        const char *str;
 
+       struct addrinfo  ai_hints;
+       struct addrinfo *ai_list;
+       struct addrinfo *ai_ptr;
+       int status;
+
        str = global_option_get ("Hostname");
        if (str != NULL)
        {
                strncpy (hostname_g, str, sizeof (hostname_g));
+               hostname_g[sizeof (hostname_g) - 1] = '\0';
+               return (0);
        }
-       else
+
+       if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
        {
-               if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
-               {
-                       fprintf (stderr, "`gethostname' failed and no "
-                                       "hostname was configured.\n");
-                       return (-1);
-               }
+               fprintf (stderr, "`gethostname' failed and no "
+                               "hostname was configured.\n");
+               return (-1);
+       }
+
+       str = global_option_get ("FQDNLookup");
+       if ((strcasecmp ("false", str) == 0)
+                       || (strcasecmp ("no", str) == 0)
+                       || (strcasecmp ("off", str) == 0))
+               return (0);
+
+       memset (&ai_hints, '\0', sizeof (ai_hints));
+       ai_hints.ai_flags = AI_CANONNAME;
+
+       status = getaddrinfo (hostname_g, NULL, &ai_hints, &ai_list);
+       if (status != 0)
+       {
+               ERROR ("getaddrinfo failed.");
+               return (-1);
        }
-       DEBUG ("hostname_g = %s;", hostname_g);
+
+       for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
+       {
+               if (ai_ptr->ai_canonname == NULL)
+                       continue;
+
+               strncpy (hostname_g, ai_ptr->ai_canonname, sizeof (hostname_g));
+               hostname_g[sizeof (hostname_g) - 1] = '\0';
+               break;
+       }
+
+       freeaddrinfo (ai_list);
+       return (0);
+} /* int init_hostname */
+
+static int init_global_variables (void)
+{
+       const char *str;
 
        str = global_option_get ("Interval");
        if (str == NULL)
@@ -80,6 +122,10 @@ static int init_global_variables (void)
        }
        DEBUG ("interval_g = %i;", interval_g);
 
+       if (init_hostname () != 0)
+               return (-1);
+       DEBUG ("hostname_g = %s;", hostname_g);
+
        return (0);
 } /* int init_global_variables */
 

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index 58de525..6178999 100644 (file)
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -5,6 +5,7 @@
 #
 
 #Hostname    "localhost"
+FQDNLookup   true
 #BaseDir     "@prefix@/var/lib/@PACKAGE_NAME@"
 #PIDFile     "@prefix@/var/run/@PACKAGE_NAME@.pid"
 #PluginDir   "@prefix@/lib/@PACKAGE_NAME@"

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index da12f86..d33b280 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -83,6 +83,23 @@ you may want to increase this if you have more than five plugins that take a
 long time to read. Mostly those are plugin that do network-IO. Setting this to
 a value higher than the number of plugins you've loaded is totally useless.
 
+=item B<Hostname> I<Name>
+
+Sets the hostname that identifies a host. If you omit this setting, the
+hostname will be determinded using the L<gethostname(2)> system call.
+
+=item B<FQDNLookup> B<true|false>
+
+If B<Hostname> is determined automatically this setting controls whether or not
+the daemon should try to figure out the "full qualified domain name", FQDN.
+This is done using a lookup of the name returned by C<gethostname>.
+
+Using this feature (i.E<nbsp>e. setting this option to B<true>) is recommended.
+However, to preserve backwards compatibility the default is set to B<false>.
+The sample config file that is installed with C<makeE<nbsp>install> includes a
+line with sets this option, though, so that default installations will have
+this setting enabled.
+
 =back
 
 =head1 PLUGIN OPTIONS

diff --git a/src/configfile.c b/src/configfile.c
index 0310ca8..a04a10d 100644 (file)
--- a/src/configfile.c
+++ b/src/configfile.c
@@ -83,12 +83,13 @@ static int cf_value_map_num = STATIC_ARRAY_LEN (cf_value_map);
 
 static cf_global_option_t cf_global_options[] =
 {
-       {"BaseDir",   NULL, PKGLOCALSTATEDIR},
-       {"PIDFile",   NULL, PIDFILE},
-       {"Hostname",  NULL, NULL},
-       {"Interval",  NULL, "10"},
+       {"BaseDir",     NULL, PKGLOCALSTATEDIR},
+       {"PIDFile",     NULL, PIDFILE},
+       {"Hostname",    NULL, NULL},
+       {"FQDNLookup",  NULL, "false"},
+       {"Interval",    NULL, "10"},
        {"ReadThreads", NULL, "5"},
-       {"TypesDB",   NULL, PLUGINDIR"/types.db"} /* FIXME: Configure path */
+       {"TypesDB",     NULL, PLUGINDIR"/types.db"} /* FIXME: Configure path */
 };
 static int cf_global_options_num = STATIC_ARRAY_LEN (cf_global_options);
 
@@ -173,6 +174,13 @@ static int dispatch_global_option (const oconfig_item_t *ci)
                tmp[127] = '\0';
                return (global_option_set (ci->key, tmp));
        }
+       else if (ci->values[0].type == OCONFIG_TYPE_BOOLEAN)
+       {
+               if (ci->values[0].value.boolean)
+                       return (global_option_set (ci->key, "true"));
+               else
+                       return (global_option_set (ci->key, "false"));
+       }
 
        return (-1);
 } /* int dispatch_global_option */