res_statsd.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <dlee@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
/*!
 * \brief Support for publishing to a StatsD server.
 *
 * \author David M. Lee, II <dlee@digium.com>
 * \since 12
 */
 
/*** MODULEINFO
    <support_level>extended</support_level>
 ***/
 
/*** DOCUMENTATION
    <configInfo name="res_statsd" language="en_US">
        <synopsis>StatsD client</synopsis>
        <description>
            <para>The <literal>res_statsd</literal> module provides an API that
            allows Asterisk and its modules to send statistics to a StatsD
            server. It only provides a means to communicate with a StatsD server
            and does not send any metrics of its own.</para>
            <para>An example module, <literal>res_chan_stats</literal>, is
            provided which uses the API exposed by this module to send channel
            statistics to the configured StatsD server.</para>
            <para>More information about StatsD can be found at
            https://github.com/statsd/statsd</para>
        </description>
        <configFile name="statsd.conf">
            <configObject name="global">
                <synopsis>Global configuration settings</synopsis>
                <configOption name="enabled">
                    <synopsis>Enable/disable the StatsD module</synopsis>
                </configOption>
                <configOption name="server">
                    <synopsis>Address of the StatsD server</synopsis>
                </configOption>
                <configOption name="prefix">
                    <synopsis>Prefix to prepend to every metric</synopsis>
                </configOption>
                <configOption name="add_newline">
                    <synopsis>Append a newline to every event. This is useful if
                    you want to fake out a server using netcat
                    (nc -lu 8125)</synopsis>
                </configOption>
                <configOption name="meter_support">
                    <synopsis>Enable/disable the non-standard StatsD Meter type,
                    if disabled falls back to counter and will append a "_meter" suffix to the metric name</synopsis>
                </configOption>
            </configObject>
        </configFile>
    </configInfo>
***/
 
#include "asterisk.h"
 
#include "asterisk/config_options.h"
#include "asterisk/module.h"
#include "asterisk/netsock2.h"
 
#define AST_API_MODULE
#include "asterisk/statsd.h"
 
#define DEFAULT_STATSD_PORT 8125
 
#define MAX_PREFIX 40
 
/*! Socket for sending statd messages */
static int socket_fd = -1;
 
/*! \brief Global configuration options for statsd client. */
struct conf_global_options {
    /*! Enabled by default, disabled if false. */
    int enabled;
    /*! Disabled by default, appends newlines to all messages when enabled. */
    int add_newline;
    /*! Statsd server address[:port]. */
    struct ast_sockaddr statsd_server;
    /*! Prefix to put on every stat. */
    char prefix[MAX_PREFIX + 1];
    /*! Enabled support for non-standard Meter type by default, falls back to counter if disabled */
    int meter_support;
};
 
/*! \brief All configuration options for statsd client. */
struct conf {
    /*! The general section configuration options. */
    struct conf_global_options *global;
};
 
/*! \brief Locking container for safe configuration access. */
static AO2_GLOBAL_OBJ_STATIC(confs);
 
static void conf_server(const struct conf *cfg, struct ast_sockaddr *addr)
{
    *addr = cfg->global->statsd_server;
    if (ast_sockaddr_port(addr) == 0) {
        ast_sockaddr_set_port(addr, DEFAULT_STATSD_PORT);
    }
}
 
void AST_OPTIONAL_API_NAME(ast_statsd_log_string)(const char *metric_name,
    const char *metric_type, const char *value, double sample_rate)
{
    struct conf *cfg;
    struct ast_str *msg;
    size_t len;
    struct ast_sockaddr statsd_server;
 
    if (socket_fd == -1) {
        return;
    }
 
    /* Rates <= 0.0 never get logged.
     * Rates >= 1.0 always get logged.
     * All others leave it to chance.
     */
    if (sample_rate <= 0.0 ||
        (sample_rate < 1.0 && sample_rate < ast_random_double())) {
        return;
    }
 
    cfg = ao2_global_obj_ref(confs);
    conf_server(cfg, &statsd_server);
 
    msg = ast_str_create(40);
    if (!msg) {
        ao2_cleanup(cfg);
        return;
    }
 
    if (!ast_strlen_zero(cfg->global->prefix)) {
        ast_str_append(&msg, 0, "%s.", cfg->global->prefix);
    }
 
    if (!cfg->global->meter_support && strcmp(metric_type, AST_STATSD_METER)) {
        ast_str_append(&msg, 0, "%s_meter:%s|%s", metric_name, value, AST_STATSD_COUNTER);
    } else {
        ast_str_append(&msg, 0, "%s:%s|%s", metric_name, value, metric_type);
    }
 
    if (sample_rate < 1.0) {
        ast_str_append(&msg, 0, "|@%.2f", sample_rate);
    }
 
    if (cfg->global->add_newline) {
        ast_str_append(&msg, 0, "\n");
    }
 
    len = ast_str_strlen(msg);
 
    ast_debug(6, "Sending statistic %s to StatsD server\n", ast_str_buffer(msg));
    ast_sendto(socket_fd, ast_str_buffer(msg), len, 0, &statsd_server);
 
    ao2_cleanup(cfg);
    ast_free(msg);
}
 
void AST_OPTIONAL_API_NAME(ast_statsd_log_full)(const char *metric_name,
    const char *metric_type, intmax_t value, double sample_rate)
{
    char char_value[30];
    snprintf(char_value, sizeof(char_value), "%jd", value);
 
    ast_statsd_log_string(metric_name, metric_type, char_value, sample_rate);
 
}
 
AST_THREADSTORAGE(statsd_buf);
 
void AST_OPTIONAL_API_NAME(ast_statsd_log_string_va)(const char *metric_name,
    const char *metric_type, const char *value, double sample_rate, ...)
{
    struct ast_str *buf;
    va_list ap;
    int res;
 
    buf = ast_str_thread_get(&statsd_buf, 128);
    if (!buf) {
        return;
    }
 
    va_start(ap, sample_rate);
    res = ast_str_set_va(&buf, 0, metric_name, ap);
    va_end(ap);
 
    if (res == AST_DYNSTR_BUILD_FAILED) {
        return;
    }
 
    ast_statsd_log_string(ast_str_buffer(buf), metric_type, value, sample_rate);
}
 
void AST_OPTIONAL_API_NAME(ast_statsd_log_full_va)(const char *metric_name,
    const char *metric_type, intmax_t value, double sample_rate, ...)
{
    struct ast_str *buf;
    va_list ap;
    int res;
 
    buf = ast_str_thread_get(&statsd_buf, 128);
    if (!buf) {
        return;
    }
 
    va_start(ap, sample_rate);
    res = ast_str_set_va(&buf, 0, metric_name, ap);
    va_end(ap);
 
    if (res == AST_DYNSTR_BUILD_FAILED) {
        return;
    }
 
    ast_statsd_log_full(ast_str_buffer(buf), metric_type, value, sample_rate);
}
 
void AST_OPTIONAL_API_NAME(ast_statsd_log)(const char *metric_name,
    const char *metric_type, intmax_t value)
{
    char char_value[30];
    snprintf(char_value, sizeof(char_value), "%jd", value);
 
    ast_statsd_log_string(metric_name, metric_type, char_value, 1.0);
}
 
void AST_OPTIONAL_API_NAME(ast_statsd_log_sample)(const char *metric_name,
    intmax_t value, double sample_rate)
{
    char char_value[30];
    snprintf(char_value, sizeof(char_value), "%jd", value);
 
    ast_statsd_log_string(metric_name, AST_STATSD_COUNTER, char_value,
        sample_rate);
}
 
/*! \brief Mapping of the statsd conf struct's globals to the
 *         general context in the config file. */
static struct aco_type global_option = {
    .type = ACO_GLOBAL,
    .name = "global",
    .item_offset = offsetof(struct conf, global),
    .category = "general",
    .category_match = ACO_WHITELIST_EXACT,
};
 
static struct aco_type *global_options[] = ACO_TYPES(&global_option);
 
/*! \brief Disposes of the statsd conf object */
static void conf_destructor(void *obj)
{
    struct conf *cfg = obj;
    ao2_cleanup(cfg->global);
}
 
/*! \brief Creates the statis http conf object. */
static void *conf_alloc(void)
{
    struct conf *cfg;
 
    if (!(cfg = ao2_alloc(sizeof(*cfg), conf_destructor))) {
        return NULL;
    }
 
    if (!(cfg->global = ao2_alloc(sizeof(*cfg->global), NULL))) {
        ao2_ref(cfg, -1);
        return NULL;
    }
    return cfg;
}
 
/*! \brief The conf file that's processed for the module. */
static struct aco_file conf_file = {
    /*! The config file name. */
    .filename = "statsd.conf",
    /*! The mapping object types to be processed. */
    .types = ACO_TYPES(&global_option),
};
 
CONFIG_INFO_STANDARD(cfg_info, confs, conf_alloc,
             .files = ACO_FILES(&conf_file));
 
/*! \brief Helper function to check if module is enabled. */
static char is_enabled(void)
{
    RAII_VAR(struct conf *, cfg, ao2_global_obj_ref(confs), ao2_cleanup);
    return cfg->global->enabled;
}
 
static int statsd_init(void)
{
    RAII_VAR(struct conf *, cfg, ao2_global_obj_ref(confs), ao2_cleanup);
    char *server;
    struct ast_sockaddr statsd_server;
 
    ast_assert(is_enabled());
 
    ast_debug(3, "Configuring StatsD client.\n");
 
    if (socket_fd == -1) {
        ast_debug(3, "Creating StatsD socket.\n");
        socket_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        if (socket_fd == -1) {
            perror("Error creating StatsD socket");
            return -1;
        }
    }
 
    conf_server(cfg, &statsd_server);
    server = ast_sockaddr_stringify_fmt(&statsd_server,
        AST_SOCKADDR_STR_DEFAULT);
    ast_debug(3, "  StatsD server = %s.\n", server);
    ast_debug(3, "  add newline = %s\n", AST_YESNO(cfg->global->add_newline));
    ast_debug(3, "  prefix = %s\n", cfg->global->prefix);
 
    return 0;
}
 
static void statsd_shutdown(void)
{
    ast_debug(3, "Shutting down StatsD client.\n");
    if (socket_fd != -1) {
        close(socket_fd);
        socket_fd = -1;
    }
}
 
static int unload_module(void)
{
    statsd_shutdown();
    aco_info_destroy(&cfg_info);
    ao2_global_obj_release(confs);
    return 0;
}
 
static int load_module(void)
{
    if (aco_info_init(&cfg_info)) {
        aco_info_destroy(&cfg_info);
        return AST_MODULE_LOAD_DECLINE;
    }
 
    aco_option_register(&cfg_info, "enabled", ACO_EXACT, global_options,
        "no", OPT_BOOL_T, 1,
        FLDSET(struct conf_global_options, enabled));
 
    aco_option_register(&cfg_info, "add_newline", ACO_EXACT, global_options,
        "no", OPT_BOOL_T, 1,
        FLDSET(struct conf_global_options, add_newline));
 
    aco_option_register(&cfg_info, "server", ACO_EXACT, global_options,
        "127.0.0.1", OPT_SOCKADDR_T, 0,
        FLDSET(struct conf_global_options, statsd_server));
 
    aco_option_register(&cfg_info, "prefix", ACO_EXACT, global_options,
        "", OPT_CHAR_ARRAY_T, 0,
        CHARFLDSET(struct conf_global_options, prefix));
 
    aco_option_register(&cfg_info, "meter_support", ACO_EXACT, global_options,
        "yes", OPT_BOOL_T, 1,
        FLDSET(struct conf_global_options, meter_support));
 
    if (aco_process_config(&cfg_info, 0) == ACO_PROCESS_ERROR) {
        struct conf *cfg;
 
        ast_log(LOG_NOTICE, "Could not load statsd config; using defaults\n");
        cfg = conf_alloc();
        if (!cfg) {
            aco_info_destroy(&cfg_info);
            return AST_MODULE_LOAD_DECLINE;
        }
 
        if (aco_set_defaults(&global_option, "general", cfg->global)) {
            ast_log(LOG_ERROR, "Failed to initialize statsd defaults.\n");
            ao2_ref(cfg, -1);
            aco_info_destroy(&cfg_info);
            return AST_MODULE_LOAD_DECLINE;
        }
 
        ao2_global_obj_replace_unref(confs, cfg);
        ao2_ref(cfg, -1);
    }
 
    if (!is_enabled()) {
        return AST_MODULE_LOAD_SUCCESS;
    }
 
    if (statsd_init()) {
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}
 
static int reload_module(void)
{
    switch (aco_process_config(&cfg_info, 1)) {
    case ACO_PROCESS_OK:
        break;
    case ACO_PROCESS_UNCHANGED:
        return AST_MODULE_LOAD_SUCCESS;
    case ACO_PROCESS_ERROR:
    default:
        return AST_MODULE_LOAD_DECLINE;
    }
 
    if (is_enabled()) {
        if (statsd_init()) {
            return AST_MODULE_LOAD_DECLINE;
        }
    } else {
        statsd_shutdown();
    }
    return AST_MODULE_LOAD_SUCCESS;
}
 
/* The priority of this module is set just after realtime, since it loads
 * configuration and could be used by any other sort of module.
 */
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "StatsD client support",
    .support_level = AST_MODULE_SUPPORT_EXTENDED,
    .load = load_module,
    .unload = unload_module,
    .reload = reload_module,
    .load_pri = AST_MODPRI_REALTIME_DRIVER + 5,
);