net.unbound: Show canonical name in textual format (e.g. in shell)
libunbound does not tell us the whole chain of CNAMEs, only the final
canonical name.
This is to aid in debugging since it will only be shown in the shell.
local socket = require "socket";
local time = require "prosody.util.time".now;
local array = require "prosody.util.array";
local t_concat = table.concat;
local new_metric_registry = require "prosody.util.openmetrics".new_metric_registry;
local render_histogram_le = require "prosody.util.openmetrics".render_histogram_le;
-- BEGIN of Metric implementations
-- Gauges
local gauge_metric_mt = {}
gauge_metric_mt.__index = gauge_metric_mt
local function new_gauge_metric(full_name, impl)
local metric = {
_full_name = full_name;
_impl = impl;
value = 0;
}
setmetatable(metric, gauge_metric_mt)
return metric
end
function gauge_metric_mt:set(value)
self.value = value
self._impl:push_gauge(self._full_name, value)
end
function gauge_metric_mt:add(delta)
self.value = self.value + delta
self._impl:push_gauge(self._full_name, self.value)
end
function gauge_metric_mt:reset()
self.value = 0
self._impl:push_gauge(self._full_name, 0)
end
function gauge_metric_mt.iter_samples()
-- statsd backend does not support iteration.
return function()
return nil
end
end
-- Counters
local counter_metric_mt = {}
counter_metric_mt.__index = counter_metric_mt
local function new_counter_metric(full_name, impl)
local metric = {
_full_name = full_name,
_impl = impl,
value = 0,
}
setmetatable(metric, counter_metric_mt)
return metric
end
function counter_metric_mt:set(value)
local delta = value - self.value
self.value = value
self._impl:push_counter_delta(self._full_name, delta)
end
function counter_metric_mt:add(value)
self.value = (self.value or 0) + value
self._impl:push_counter_delta(self._full_name, value)
end
function counter_metric_mt.iter_samples()
-- statsd backend does not support iteration.
return function()
return nil
end
end
function counter_metric_mt:reset()
self.value = 0
end
-- Histograms
local histogram_metric_mt = {}
histogram_metric_mt.__index = histogram_metric_mt
local function new_histogram_metric(buckets, full_name, impl)
-- NOTE: even though the more or less proprietary dogstatsd has Its own
-- histogram implementation, we push the individual buckets in this statsd
-- backend for both consistency and compatibility across statsd
-- implementations.
local metric = {
_sum_name = full_name..".sum",
_count_name = full_name..".count",
_impl = impl,
_created = time(),
_sum = 0,
_count = 0,
}
-- the order of buckets matters unfortunately, so we cannot directly use
-- the thresholds as table keys
for i, threshold in ipairs(buckets) do
local threshold_s = render_histogram_le(threshold)
metric[i] = {
threshold = threshold,
threshold_s = threshold_s,
count = 0,
_full_name = full_name..".bucket."..(threshold_s:gsub("%.", "_")),
}
end
setmetatable(metric, histogram_metric_mt)
return metric
end
function histogram_metric_mt:sample(value)
-- According to the I-D, values must be part of all buckets
for i, bucket in pairs(self) do
if "number" == type(i) and value <= bucket.threshold then
bucket.count = bucket.count + 1
self._impl:push_counter_delta(bucket._full_name, 1)
end
end
self._sum = self._sum + value
self._count = self._count + 1
self._impl:push_gauge(self._sum_name, self._sum)
self._impl:push_counter_delta(self._count_name, 1)
end
function histogram_metric_mt.iter_samples()
-- statsd backend does not support iteration.
return function()
return nil
end
end
function histogram_metric_mt:reset()
self._created = time()
self._count = 0
self._sum = 0
for i, bucket in pairs(self) do
if "number" == type(i) then
bucket.count = 0
end
end
self._impl:push_gauge(self._sum_name, self._sum)
end
-- Summaries
local summary_metric_mt = {}
summary_metric_mt.__index = summary_metric_mt
local function new_summary_metric(full_name, impl)
local metric = {
_sum_name = full_name..".sum",
_count_name = full_name..".count",
_impl = impl,
}
setmetatable(metric, summary_metric_mt)
return metric
end
function summary_metric_mt:sample(value)
self._impl:push_counter_delta(self._sum_name, value)
self._impl:push_counter_delta(self._count_name, 1)
end
function summary_metric_mt.iter_samples()
-- statsd backend does not support iteration.
return function()
return nil
end
end
function summary_metric_mt.reset()
end
-- BEGIN of statsd client implementation
local statsd_mt = {}
statsd_mt.__index = statsd_mt
function statsd_mt:cork()
self.corked = true
self.cork_buffer = self.cork_buffer or {}
end
function statsd_mt:uncork()
self.corked = false
self:_flush_cork_buffer()
end
function statsd_mt:_flush_cork_buffer()
local buffer = self.cork_buffer
for metric_name, value in pairs(buffer) do
self:_send_gauge(metric_name, value)
buffer[metric_name] = nil
end
end
function statsd_mt:push_gauge(metric_name, value)
if self.corked then
self.cork_buffer[metric_name] = value
else
self:_send_gauge(metric_name, value)
end
end
function statsd_mt:_send_gauge(metric_name, value)
self:_send(self.prefix..metric_name..":"..tostring(value).."|g")
end
function statsd_mt:push_counter_delta(metric_name, delta)
self:_send(self.prefix..metric_name..":"..tostring(delta).."|c")
end
function statsd_mt:_send(s)
return self.sock:send(s)
end
-- END of statsd client implementation
local function build_metric_name(family_name, labels)
local parts = array { family_name }
if labels then
parts:append(labels)
end
return t_concat(parts, "/"):gsub("%.", "_"):gsub("/", ".")
end
local function new(config)
if not config or not config.statsd_server then
return nil, "No statsd server specified in the config, please see https://prosody.im/doc/statistics";
end
local sock = socket.udp();
sock:setpeername(config.statsd_server, config.statsd_port or 8125);
local prefix = (config.prefix or "prosody")..".";
local impl = {
metric_registry = nil;
sock = sock;
prefix = prefix;
};
setmetatable(impl, statsd_mt)
local backend = {
gauge = function(family_name, labels)
return new_gauge_metric(build_metric_name(family_name, labels), impl)
end;
counter = function(family_name, labels)
return new_counter_metric(build_metric_name(family_name, labels), impl)
end;
histogram = function(buckets, family_name, labels)
return new_histogram_metric(buckets, build_metric_name(family_name, labels), impl)
end;
summary = function(family_name, labels, extra)
return new_summary_metric(build_metric_name(family_name, labels), impl, extra)
end;
};
impl.metric_registry = new_metric_registry(backend);
return impl;
end
return {
new = new;
}