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spec/util_xmppstream_spec.lua @ 11523:5f15ab7c6ae5
Statistics: Rewrite statistics backends to use OpenMetrics
The metric subsystem of Prosody has had some shortcomings from
the perspective of the current state-of-the-art in metric
observability.
The OpenMetrics standard [0] is a formalization of the data
model (and serialization format) of the well-known and
widely-used Prometheus [1] software stack.
The previous stats subsystem of Prosody did not map well to that
format (see e.g. [2] and [3]); the key reason is that it was
trying to do too much math on its own ([2]) while lacking
first-class support for "families" of metrics ([3]) and
structured metric metadata (despite the `extra` argument to
metrics, there was no standard way of representing common things
like "tags" or "labels").
Even though OpenMetrics has grown from the Prometheus world of
monitoring, it maps well to other popular monitoring stacks
such as:
- InfluxDB (labels can be mapped to tags and fields as necessary)
- Carbon/Graphite (labels can be attached to the metric name with
dot-separation)
- StatsD (see graphite when assuming that graphite is used as
backend, which is the default)
The util.statsd module has been ported to use the OpenMetrics
model as a proof of concept. An implementation which exposes
the util.statistics backend data as Prometheus metrics is
ready for publishing in prosody-modules (most likely as
mod_openmetrics_prometheus to avoid breaking existing 0.11
deployments).
At the same time, the previous measure()-based API had one major
advantage: It is really simple and easy to use without requiring
lots of knowledge about OpenMetrics or similar concepts. For that
reason as well as compatibility with existing code, it is preserved
and may even be extended in the future.
However, code relying on the `stats-updated` event as well as
`get_stats` from `statsmanager` will break because the data
model has changed completely; in case of `stats-updated`, the
code will simply not run (as the event was renamed in order
to avoid conflicts); the `get_stats` function has been removed
completely (so it will cause a traceback when it is attempted
to be used).
Note that the measure_*_event methods have been removed from
the module API. I was unable to find any uses or documentation
and thus deemed they should not be ported. Re-implementation is
possible when necessary.
[0]: https://openmetrics.io/
[1]: https://prometheus.io/
[2]: #959
[3]: #960
author | Jonas Schäfer <jonas@wielicki.name> |
---|---|
date | Sun, 18 Apr 2021 11:47:41 +0200 |
parent | 9021:548ba4090012 |
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local xmppstream = require "util.xmppstream"; describe("util.xmppstream", function() local function test(xml, expect_success, ex) local stanzas = {}; local session = { notopen = true }; local callbacks = { stream_ns = "streamns"; stream_tag = "stream"; default_ns = "stanzans"; streamopened = function (_session) assert.are.equal(session, _session); assert.are.equal(session.notopen, true); _session.notopen = nil; return true; end; handlestanza = function (_session, stanza) assert.are.equal(session, _session); assert.are.equal(_session.notopen, nil); table.insert(stanzas, stanza); end; streamclosed = function (_session) assert.are.equal(session, _session); assert.are.equal(_session.notopen, nil); _session.notopen = nil; end; } if type(ex) == "table" then for k, v in pairs(ex) do if k ~= "_size_limit" then callbacks[k] = v; end end end local stream = xmppstream.new(session, callbacks, ex and ex._size_limit or nil); local ok, err = pcall(function () assert(stream:feed(xml)); end); if ok and type(expect_success) == "function" then expect_success(stanzas); end assert.are.equal(not not ok, not not expect_success, "Expected "..(expect_success and ("success ("..tostring(err)..")") or "failure")); end local function test_stanza(stanza, expect_success, ex) return test([[<stream:stream xmlns:stream="streamns" xmlns="stanzans">]]..stanza, expect_success, ex); end describe("#new()", function() it("should work", function() test([[<stream:stream xmlns:stream="streamns"/>]], true); test([[<stream xmlns="streamns"/>]], true); -- Incorrect stream tag name should be rejected test([[<stream1 xmlns="streamns"/>]], false); -- Incorrect stream namespace should be rejected test([[<stream xmlns="streamns1"/>]], false); -- Invalid XML should be rejected test("<>", false); test_stanza("<message/>", function (stanzas) assert.are.equal(#stanzas, 1); assert.are.equal(stanzas[1].name, "message"); end); test_stanza("< message>>>>/>\n", false); test_stanza([[<x xmlns:a="b"> <y xmlns:a="c"> <a:z/> </y> <a:z/> </x>]], function (stanzas) assert.are.equal(#stanzas, 1); local s = stanzas[1]; assert.are.equal(s.name, "x"); assert.are.equal(#s.tags, 2); assert.are.equal(s.tags[1].name, "y"); assert.are.equal(s.tags[1].attr.xmlns, nil); assert.are.equal(s.tags[1].tags[1].name, "z"); assert.are.equal(s.tags[1].tags[1].attr.xmlns, "c"); assert.are.equal(s.tags[2].name, "z"); assert.are.equal(s.tags[2].attr.xmlns, "b"); assert.are.equal(s.namespaces, nil); end); end); end); it("should allow an XML declaration", function () test([[<?xml version="1.0" encoding="UTF-8"?><stream xmlns="streamns"/>]], true); test([[<?xml version="1.0" encoding="UTF-8" standalone="yes" ?><stream xmlns="streamns"/>]], true); test([[<?xml version="1.0" encoding="utf-8" ?><stream xmlns="streamns"/>]], true); end); it("should not accept XML versions other than 1.0", function () test([[<?xml version="1.1" encoding="utf-8" ?><stream xmlns="streamns"/>]], false); end); it("should not allow a misplaced XML declaration", function () test([[<stream xmlns="streamns"><?xml version="1.0" encoding="UTF-8"?></stream>]], false); end); describe("should forbid restricted XML:", function () it("comments", function () test_stanza("<!-- hello world -->", false); end); it("DOCTYPE", function () test([[<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE stream SYSTEM "mydtd.dtd">]], false); end); it("incorrect encoding specification", function () -- This is actually caught by the underlying XML parser test([[<?xml version="1.0" encoding="UTF-16"?><stream xmlns="streamns"/>]], false); end); it("non-UTF8 encodings: ISO-8859-1", function () test([[<?xml version="1.0" encoding="ISO-8859-1"?><stream xmlns="streamns"/>]], false); end); it("non-UTF8 encodings: UTF-16", function () -- <?xml version="1.0" encoding="UTF-16"?><stream xmlns="streamns"/> -- encoded into UTF-16 local hx = ([[fffe3c003f0078006d006c002000760065007200730069006f006e003d00 220031002e0030002200200065006e0063006f00640069006e0067003d00 22005500540046002d003100360022003f003e003c007300740072006500 61006d00200078006d006c006e0073003d00220073007400720065006100 6d006e00730022002f003e00]]):gsub("%x%x", function (c) return string.char(tonumber(c, 16)); end); test(hx, false); end); it("processing instructions", function () test([[<stream xmlns="streamns"><?xml-stylesheet type="text/xsl" href="style.xsl"?></stream>]], false); end); end); end);