2 * /usr/share/doc/collectd/examples/myplugin.c
4 * A plugin template for collectd.
6 * Written by Sebastian Harl <sh@tokkee.org>
8 * This is free software; you can redistribute it and/or modify it under
9 * the terms of the GNU General Public License as published by the Free
10 * Software Foundation; only version 2 of the License is applicable.
15 * - plugins are executed in parallel, thus, thread-safe
16 * functions need to be used
17 * - each of the functions below (except module_register)
27 #ifndef __USE_ISOC99 /* required for NAN */
28 # define DISABLE_ISOC99 1
29 # define __USE_ISOC99 1
30 #endif /* !defined(__USE_ISOC99) */
33 # undef DISABLE_ISOC99
35 #endif /* DISABLE_ISOC99 */
39 #endif /* ! HAVE_CONFIG */
41 #include <collectd/collectd.h>
42 #include <collectd/common.h>
43 #include <collectd/plugin.h>
46 * data source definition:
47 * - name of the data source
48 * - type of the data source (DS_TYPE_GAUGE, DS_TYPE_COUNTER)
49 * - minimum allowed value
50 * - maximum allowed value
52 static data_source_t dsrc[1] =
54 { "my_ds", DS_TYPE_GAUGE, 0, NAN }
58 * data set definition:
59 * - name of the data set
60 * - number of data sources
61 * - list of data sources
63 static data_set_t ds =
65 "myplugin", STATIC_ARRAY_SIZE (dsrc), dsrc
69 * This function is called once upon startup to initialize the plugin.
71 static int my_init (void)
73 /* open sockets, initialize data structures, ... */
75 /* A return value != 0 indicates an error and causes the plugin to be
78 } /* static int my_init (void) */
81 * This function is called in regular intervalls to collect the data.
83 static int my_read (void)
85 value_t values[1]; /* the size of this list should equal the number of
87 value_list_t vl = VALUE_LIST_INIT;
89 /* do the magic to read the data */
90 values[0].gauge = random ();
94 vl.time = time (NULL);
95 strcpy (vl.host, hostname_g);
96 strcpy (vl.plugin, "myplugin");
97 /* optionally set vl.plugin_instance and vl.type_instance to reasonable
98 * values (default: "") */
100 /* dispatch the values to collectd which passes them on to all registered
101 * write functions - the first argument is used to lookup the data set
103 plugin_dispatch_values ("myplugin", &vl);
105 /* A return value != 0 indicates an error and the plugin will be skipped
106 * for an increasing amount of time. */
108 } /* static int my_read (void) */
111 * This function is called after values have been dispatched to collectd.
113 static int my_write (const data_set_t *ds, const value_list_t *vl)
115 char name[1024] = "";
118 if (ds->ds_num != vl->values_len) {
119 plugin_log (LOG_WARNING, "DS number does not match values length");
123 /* get the default base filename for the output file - depending on the
124 * provided values this will be something like
125 * <host>/<plugin>[-<plugin_type>]/<instance>[-<instance_type>] */
126 if (0 != format_name (name, 1024, vl->host, vl->plugin,
127 vl->plugin_instance, ds->type, vl->type_instance))
130 for (i = 0; i < ds->ds_num; ++i) {
131 /* do the magic to output the data */
132 printf ("%s (%s) at %i: ", name,
133 (ds->ds->type == DS_TYPE_GAUGE) ? "GAUGE" : "COUNTER",
136 if (ds->ds->type == DS_TYPE_GAUGE)
137 printf ("%f\n", vl->values[i].gauge);
139 printf ("%lld\n", vl->values[i].counter);
142 } /* static int my_write (data_set_t *, value_list_t *) */
145 * This function is called when plugin_log () has been used.
147 static void my_log (int severity, const char *msg)
149 printf ("LOG: %i - %s\n", severity, msg);
151 } /* static void my_log (int, const char *) */
154 * This function is called when plugin_dispatch_notification () has been used.
156 static int my_notify (const notification_t *notif)
158 char time_str[32] = "";
159 struct tm *tm = NULL;
163 if (NULL == (tm = localtime (¬if->time)))
166 n = strftime (time_str, 32, "%F %T", tm);
170 printf ("NOTIF (%s): %i - ", time_str, notif->severity);
172 if ('\0' != *notif->host)
173 printf ("%s: ", notif->host);
175 if ('\0' != *notif->plugin)
176 printf ("%s: ", notif->plugin);
178 if ('\0' != *notif->plugin_instance)
179 printf ("%s: ", notif->plugin_instance);
181 if ('\0' != *notif->type)
182 printf ("%s: ", notif->type);
184 if ('\0' != *notif->type_instance)
185 printf ("%s: ", notif->type_instance);
187 printf ("%s\n", notif->message);
189 } /* static int my_notify (notification_t *) */
192 * This function is called before shutting down collectd.
194 static int my_shutdown (void)
196 /* close sockets, free data structures, ... */
198 } /* static int my_shutdown (void) */
201 * This function is called after loading the plugin to register it with
204 void module_register (void)
206 plugin_register_log ("myplugin", my_log);
207 plugin_register_notification ("myplugin", my_notify);
208 plugin_register_data_set (&ds);
209 plugin_register_read ("myplugin", my_read);
210 plugin_register_init ("myplugin", my_init);
211 plugin_register_write ("myplugin", my_write);
212 plugin_register_shutdown ("myplugin", my_shutdown);
214 } /* void module_register (void) */