1 /*
2 * /usr/share/doc/collectd/examples/myplugin.c
3 *
4 * A plugin template for collectd.
5 *
6 * Written by Sebastian Harl <sh@tokkee.org>
7 *
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.
11 */
13 /*
14 * Notes:
15 * - plugins are executed in parallel, thus, thread-safe
16 * functions need to be used
17 * - each of the functions below (except module_register)
18 * is optional
19 */
21 #if ! HAVE_CONFIG_H
23 #include <stdlib.h>
25 #include <string.h>
27 #ifndef __USE_ISOC99 /* required for NAN */
28 # define DISABLE_ISOC99 1
29 # define __USE_ISOC99 1
30 #endif /* !defined(__USE_ISOC99) */
31 #include <math.h>
32 #if DISABLE_ISOC99
33 # undef DISABLE_ISOC99
34 # undef __USE_ISOC99
35 #endif /* DISABLE_ISOC99 */
37 #include <time.h>
39 #endif /* ! HAVE_CONFIG */
41 #include <collectd/collectd.h>
43 #include <collectd/common.h>
44 #include <collectd/plugin.h>
46 /*
47 * data source definition:
48 * - name of the data source
49 * - type of the data source (DS_TYPE_GAUGE, DS_TYPE_COUNTER)
50 * - minimum allowed value
51 * - maximum allowed value
52 */
53 static data_source_t dsrc[1] =
54 {
55 { "my_ds", DS_TYPE_GAUGE, 0, NAN }
56 };
58 /*
59 * data set definition:
60 * - name of the data set
61 * - number of data sources
62 * - list of data sources
63 *
64 * NOTE: If you're defining a custom data-set, you have to make that known to
65 * any servers as well. Else, the server is not able to store values using the
66 * type defined by that data-set.
67 * It is strongly recommended to use one of the types and data-sets
68 * pre-defined in the types.db file.
69 */
70 static data_set_t ds =
71 {
72 "myplugin", STATIC_ARRAY_SIZE (dsrc), dsrc
73 };
75 /*
76 * This function is called once upon startup to initialize the plugin.
77 */
78 static int my_init (void)
79 {
80 /* open sockets, initialize data structures, ... */
82 /* A return value != 0 indicates an error and causes the plugin to be
83 disabled. */
84 return 0;
85 } /* static int my_init (void) */
87 /*
88 * This function is called in regular intervalls to collect the data.
89 */
90 static int my_read (void)
91 {
92 value_t values[1]; /* the size of this list should equal the number of
93 data sources */
94 value_list_t vl = VALUE_LIST_INIT;
96 /* do the magic to read the data */
97 values[0].gauge = random ();
99 vl.values = values;
100 vl.values_len = 1;
101 vl.time = time (NULL);
102 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
103 sstrncpy (vl.plugin, "myplugin", sizeof (vl.plugin));
105 /* it is strongly recommended to use a type defined in the types.db file
106 * instead of a custom type */
107 sstrncpy (vl.type, "myplugin", sizeof (vl.plugin));
108 /* optionally set vl.plugin_instance and vl.type_instance to reasonable
109 * values (default: "") */
111 /* dispatch the values to collectd which passes them on to all registered
112 * write functions */
113 plugin_dispatch_values (&vl);
115 /* A return value != 0 indicates an error and the plugin will be skipped
116 * for an increasing amount of time. */
117 return 0;
118 } /* static int my_read (void) */
120 /*
121 * This function is called after values have been dispatched to collectd.
122 */
123 static int my_write (const data_set_t *ds, const value_list_t *vl,
124 user_data_t *ud)
125 {
126 char name[1024] = "";
127 int i = 0;
129 if (ds->ds_num != vl->values_len) {
130 plugin_log (LOG_WARNING, "DS number does not match values length");
131 return -1;
132 }
134 /* get the default base filename for the output file - depending on the
135 * provided values this will be something like
136 * <host>/<plugin>[-<plugin_type>]/<instance>[-<instance_type>] */
137 if (0 != format_name (name, 1024, vl->host, vl->plugin,
138 vl->plugin_instance, ds->type, vl->type_instance))
139 return -1;
141 for (i = 0; i < ds->ds_num; ++i) {
142 /* do the magic to output the data */
143 printf ("%s (%s) at %i: ", name,
144 (ds->ds->type == DS_TYPE_GAUGE) ? "GAUGE" : "COUNTER",
145 (int)vl->time);
147 if (ds->ds->type == DS_TYPE_GAUGE)
148 printf ("%f\n", vl->values[i].gauge);
149 else
150 printf ("%lld\n", vl->values[i].counter);
151 }
152 return 0;
153 } /* static int my_write (data_set_t *, value_list_t *) */
155 /*
156 * This function is called when plugin_log () has been used.
157 */
158 static void my_log (int severity, const char *msg, user_data_t *ud)
159 {
160 printf ("LOG: %i - %s\n", severity, msg);
161 return;
162 } /* static void my_log (int, const char *) */
164 /*
165 * This function is called when plugin_dispatch_notification () has been used.
166 */
167 static int my_notify (const notification_t *notif, user_data_t *ud)
168 {
169 char time_str[32] = "";
170 struct tm *tm = NULL;
172 int n = 0;
174 if (NULL == (tm = localtime (¬if->time)))
175 time_str[0] = '\0';
177 n = strftime (time_str, 32, "%F %T", tm);
178 if (n >= 32) n = 31;
179 time_str[n] = '\0';
181 printf ("NOTIF (%s): %i - ", time_str, notif->severity);
183 if ('\0' != *notif->host)
184 printf ("%s: ", notif->host);
186 if ('\0' != *notif->plugin)
187 printf ("%s: ", notif->plugin);
189 if ('\0' != *notif->plugin_instance)
190 printf ("%s: ", notif->plugin_instance);
192 if ('\0' != *notif->type)
193 printf ("%s: ", notif->type);
195 if ('\0' != *notif->type_instance)
196 printf ("%s: ", notif->type_instance);
198 printf ("%s\n", notif->message);
199 return 0;
200 } /* static int my_notify (notification_t *) */
202 /*
203 * This function is called before shutting down collectd.
204 */
205 static int my_shutdown (void)
206 {
207 /* close sockets, free data structures, ... */
208 return 0;
209 } /* static int my_shutdown (void) */
211 /*
212 * This function is called after loading the plugin to register it with
213 * collectd.
214 */
215 void module_register (void)
216 {
217 plugin_register_log ("myplugin", my_log, /* user data */ NULL);
218 plugin_register_notification ("myplugin", my_notify,
219 /* user data */ NULL);
220 plugin_register_data_set (&ds);
221 plugin_register_read ("myplugin", my_read);
222 plugin_register_init ("myplugin", my_init);
223 plugin_register_write ("myplugin", my_write, /* user data */ NULL);
224 plugin_register_shutdown ("myplugin", my_shutdown);
225 return;
226 } /* void module_register (void) */