From: Sebastian Harl Date: Sun, 22 Apr 2007 22:07:38 +0000 (+0000) Subject: myplugin.c: Updated for collectd-4. X-Git-Tag: collectd-4.0.2-1~71 X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=03c4f01e60104bc8e98c9c96692e64a41fe25a18;p=pkg-collectd.git myplugin.c: Updated for collectd-4. Basically this is a complete rewrite. --- diff --git a/debian/examples/myplugin.c b/debian/examples/myplugin.c index 775a340..1979e2d 100644 --- a/debian/examples/myplugin.c +++ b/debian/examples/myplugin.c @@ -1,107 +1,164 @@ /* - * /usr/share/doc/collectd/examples/sample_plugin.c + * /usr/share/doc/collectd/examples/myplugin.c * - * A sample plugin for collectd. + * A plugin template for collectd. * * Written by Sebastian Harl * * This is free software; you can redistribute it and/or modify it under - * the terms of the GNU General Public License as published by the Free - * Software Foundation; either version 2 of the License, or (at your - * option) any later version. + * the terms of the GNU General Public License as published by the Free + * Software Foundation; only version 2 of the License is applicable. + */ + +/* + * Notes: + * - plugins are executed in parallel, thus, thread-safe + * functions need to be used + * - each of the functions below (except module_register) + * is optional */ #include #include -#include /* rrd_update_file */ -#include /* plugin_* */ - -/* Optional config file support */ -/* #include */ - -/* Optional debugging support - * (only available if collectd was compiled with debugging support) */ -/* #include */ +#include +#include +#include -#define MODULE_NAME "myplugin" - -/* Name of the rrd file under DataDir (/var/lib/collectd by default) - * - * The name may contain slashes to create subdirectories. */ -static char *my_rrd = "myplugin.rrd"; +/* + * data source definition: + * - name of the data source + * - type of the data source (DS_TYPE_GAUGE, DS_TYPE_COUNTER) + * - minimum allowed value + * - maximum allowed value + */ +static data_source_t dsrc[1] = +{ + { "my_ds", DS_TYPE_GAUGE, 0, NAN } +}; -/* DS definitions for the rrd file - * - * See the rrdcreate(1) manpage for details. The heartbeat is configurable in - * collectd. It defaults to 25. */ -static char *ds_def[] = +/* + * data set definition: + * - name of the data set + * - number of data sources + * - list of data sources + */ +static data_set_t ds = { - "DS:my_ds:GAUGE:25:0:U", - NULL + "myplugin", STATIC_ARRAY_SIZE (dsrc), dsrc }; -/* DS count */ -static int ds_num = 1; +/* + * This function is called once upon startup to initialize the plugin. + */ +static int my_init (void) +{ + /* open sockets, initialize data structures, ... */ -/* Time at which the read function is called */ -extern time_t curtime; + /* A return value != 0 indicates an error and causes the plugin to be + disabled. */ + return 0; +} /* static int my_init (void) */ -/* Initialize the plugin - * - * This function is called to set up a plugin before using it. */ -static void my_init(void) +/* + * This function is called in regular intervalls to collect the data. + */ +static int my_read (void) { - /* we have nothing to do here :-) */ - return; -} + value_t values[1]; /* the size of this list should equal the number of + data sources */ + value_list_t vl = VALUE_LIST_INIT; + + /* do the magic to read the data */ + values[0].gauge = random (); + + vl.values = values; + vl.values_len = 1; + vl.time = time (NULL); + strcpy (vl.host, hostname_g); + strcpy (vl.plugin, "myplugin"); + /* optionally set vl.plugin_instance and vl.type_instance to reasonable + * values (default: "") */ + + /* dispatch the values to collectd which passes them on to all registered + * write functions - the first argument is used to lookup the data set + * definition */ + plugin_dispatch_values ("myplugin", &vl); + + /* A return value != 0 indicates an error and the plugin will be skipped + * for an increasing amount of time. */ + return 0; +} /* static int my_read (void) */ -/* Get the data - * - * This function implements the magic used to get the desired values that - * should be stored in the rrd file. It uses plugin_submit to transfer the - * data to whatever place is configured in the config file. If there are more - * than one instances you should pass a uniq identifier as seconds argument to - * the plugin_submit function. */ -#define BUFSIZE 256 -static void my_read(void) +/* + * This function is called after values have been dispatched to collectd. + */ +static int my_write (const data_set_t *ds, const value_list_t *vl) { - long int data = 0; - char buf[BUFSIZE] = ""; - - /* magic ;-) */ - data = random(); + char name[1024] = ""; + int i = 0; + + if (ds->ds_num != vl->values_len) { + plugin_log (LOG_WARNING, "DS number does not match values length"); + return -1; + } + + /* get the default base filename for the output file - depending on the + * provided values this will be something like + * /[-]/[-] */ + if (0 != format_name (name, 1024, vl->host, vl->plugin, + vl->plugin_instance, ds->type, vl->type_instance)) + return -1; + + for (i = 0; i < ds->ds_num; ++i) { + /* do the magic to output the data */ + printf ("%s (%s) at %i: ", name, + (ds->ds->type == DS_TYPE_GAUGE) ? "GAUGE" : "COUNTER", + (int)vl->time); + + if (ds->ds->type == DS_TYPE_GAUGE) + printf ("%f\n", vl->values[i].gauge); + else + printf ("%lld\n", vl->values[i].counter); + } + return 0; +} /* static int my_write (data_set_t *, value_list_t *) */ - if (snprintf(buf, BUFSIZE, "%u:%li", - (unsigned int)curtime, data) >= BUFSIZE) - return; - - plugin_submit(MODULE_NAME, "-", buf); - return; -} -#undef BUFSIZE +/* + * This function is called when plugin_log () has been used. + */ +static void my_log (int severity, const char *msg) +{ + printf ("LOG: %i - %s\n", severity, msg); + return; +} /* static void my_log (int, const char *) */ -/* Save the data - * - * This function saves the data to the appropriate location by calling - * rrd_update_file. It is used to "calculate" the filename and DS definition - * appropriate for the given instance. */ -static void my_write(host, inst, val) - char *host; - char *inst; - char *val; +/* + * This function is called before shutting down collectd. + */ +static int my_shutdown (void) { - rrd_update_file(host, my_rrd, val, ds_def, ds_num); - return; -} + /* close sockets, free data structures, ... */ + return 0; +} /* static int my_shutdown (void) */ -/* Register the plugin - * - * This function registers the plugin with collectd. It has to be named - * "module_register". */ -void module_register(void) +/* + * This function is called after loading the plugin to register it with + * collectd. + */ +void module_register (modreg_e load) { - plugin_register(MODULE_NAME, my_init, my_read, my_write); + plugin_register_log ("myplugin", my_log); + + if (load & MR_DATASETS) + plugin_register_data_set (&ds); + + if (load & MR_READ) + plugin_register_read ("myplugin", my_read); + + plugin_register_init ("myplugin", my_init); + plugin_register_write ("myplugin", my_write); + plugin_register_shutdown ("myplugin", my_shutdown); return; -} +} /* void module_register (modreg_e) */