Clone the collectd repo: https://github.com/collectd/collectd.git
An Overview of the architecture of a collectd plugin exists here: https://collectd.org/wiki/index.php/Plugin_architecture
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#include "collectd.h"
#include "common.h"
#define PLUGIN_NAME "my_plugin"
static _Bool g_enable_option1;
static char g_option2 [DATA_MAX_NAME_LEN];
static int my_config_function(oconfig_item_t *ci) {
int ret = 0;
INFO (PLUGIN_NAME ": %s:%d", __FUNCTION__, __LINE__);
for (int i = 0; i < ci->children_num; i++) {
oconfig_item_t *child = ci->children + i;
if (strcasecmp("Option1", child->key) == 0) {
ret = cf_util_get_boolean(child, & g_enable_option1);
} else if (strcasecmp("Option2", child->key) == 0) {
ret = cf_util_get_string_buffer(child, g_option2,
sizeof(g_option2));
}else {
ERROR(PLUGIN_NAME ": Unknown configuration parameter \"%s\".", child->key);
ret = (-1);
}
if (ret != 0) {
INFO (PLUGIN_NAME ": %s:%d ret=%d", __FUNCTION__, __LINE__, ret);
return ret;
}
}
return (0);
}
static int my_read_function(__attribute__((unused)) user_data_t *ud) {
INFO (PLUGIN_NAME ": %s:%d", __FUNCTION__, __LINE__);
/* In order to dispatch values to the collectd daemon you need to fill out a value list and use plugin_dispatch_values() An example is provided below
*
* value_list_t vl = VALUE_LIST_INIT;
*
* vl.values = &(value_t){.derive = value}; //NOTE please change value to the actual value and use an appropriate type: checkout https://wiki.opnfv.org/display/fastpath/Collectd+101 for more info
*
* vl.values_len = 1;
* sstrncpy(vl.host, hostname_g, sizeof(vl.host));
* sstrncpy(vl.plugin, PLUGIN_NAME, sizeof(vl.plugin));
* sstrncpy(vl.plugin_instance, "my_plugin_instance", sizeof(vl.plugin_instance)); // replace my_plugin_instance with an appropriate string/instance... see the end of this wiki
* sstrncpy(vl.type, "my_plugin_type", sizeof(vl.type));// replace my_plugin_type with an appropriate string... see the end of this wiki
*
* plugin_dispatch_values(&vl);
*
*
* To dispatch a notification you need to fill out a notification structure and use plugin_dispatch_notification()
* notification_t n = {
* .severity = severity, // where severity is one of NOTIF_OKAY, NOTIF_WARNING, NOTIF_FAILURE
* .time = cdtime(),
* .message = "Some message",
* .plugin = PLUGIN_NAME};
*
* sstrncpy(n.host, hostname_g, sizeof(n.host));
* sstrncpy(n.plugin_instance, "my_plugin_instance", sizeof(n.plugin_instance)); // replace my_plugin_instance with an appropriate string... see the end of this wiki
*
* plugin_dispatch_notification(&n);
*/
return (0);
}
static int my_shutdown_function (void) {
INFO (PLUGIN_NAME ": %s:%d", __FUNCTION__, __LINE__);
return (0);
}
static int my_init_function(void) {
INFO(PLUGIN_NAME ": %s:%d", __FUNCTION__, __LINE__);
return (0);
}
void module_register(void) {
plugin_register_init("my_plugin", my_init_function);
plugin_register_complex_config("my_plugin", my_config_function);
plugin_register_complex_read(NULL, "my_plugin", my_read_function, 0, NULL);
plugin_register_shutdown("my_plugin", my_shutdown_function);
}
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Under src/ Modify the types.db file to include a new type
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my_plugin_type value:DERIVE:0:U |
Under the top level collectd directory Modify the Makefile.am file to build your plugin
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if BUILD_PLUGIN_MY_PLUGIN pkglib_LTLIBRARIES += my_plugin.la my_plugin_la_SOURCES = src/my_plugin.c my_plugin_la_CFLAGS = $(AM_CFLAGS) my_plugin_la_LDFLAGS = $(PLUGIN_LDFLAGS) endif |
Under the top level collectd directory Modify the configure.ac file to include your plugin (search for plugin_ascent="no" and add it in the correct place alphpbetically), and set it to disabled (so it doesn’t build on all platforms):
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AC_MSG_RESULT([ my_plugin. . . . . . $enable_my_plugin]) |
Under src/ Finally it’s time to configure the configuration stanzas for your new plugin. By modifygin collectd.conf.in to include:
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#@BUILD_PLUGIN_MY_PLUGIN_TRUE@LoadPlugin my_plugin #<Plugin my_plugin> # Option1 true # Option2 “example” #</Plugin> |
Under src/ Update the plugin configuration description in collectd.conf.pod
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=head2 Plugin C<my_plugin>
The I< my_plugin > plugin collects TBD.
B<Synopsis:>
<Plugin my_plugin>
Option1 true
Option2 “example”
</Plugin>
B<Options:>
=over 2
=item B<Option1> B<false>|B<true>
TBD.
=item B< Option2>B<Option2> I<some_string>
TBD.
=back |
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you should now be able to build your simple collectd plugin, in the top level directory:
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$ ./build.sh $ ./configure --prefix=$HOME/clct $ make $ make -j install |
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