# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1607441693 0
# Node ID 2ae71126e379a6814327e0e744189cdf3391916c
# Parent  281a864e74729d56b010c51c00582d5fa79ea50c
mod_sentry: New module to forward errors to a Sentry server

diff -r 281a864e7472 -r 2ae71126e379 mod_sentry/README.md
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_sentry/README.md	Tue Dec 08 15:34:53 2020 +0000
@@ -0,0 +1,135 @@
+---
+labels:
+- 'Stage-Beta'
+summary: 'Send errors to a Sentry server'
+---
+
+# Introduction
+
+This module forwards select events to a [Sentry](https://sentry.io/) server.
+
+# Configuration
+
+There is a single configuration option, `sentry`, which should be a table
+containing the following parameters (optional unless otherwise stated):
+
+`dsn`
+: **Required.** The DSN of the project in Sentry.
+
+`insecure`
+: Whether to allow untrusted HTTPS certificates.
+
+`server_name`
+: The name of the current server (defaults to the system hostname).
+
+`tags`
+: An optional table of tags that will be used as the default for all
+  events from this module.
+
+`extra`
+: An optional table of custom extra data to attach to all events from
+  this module.
+
+Example configuration:
+
+```
+sentry = {
+    dsn = "https://37iNFnR4tferFhoTPNe8X0@example.com/11";
+    tags = {
+        environment = "prod";
+    };
+}
+```
+
+## Log forwarding
+
+You can configure log messages to be automatically forwarded to Sentry.
+This example will send all "warn" and "error" messages to Sentry, while
+sending all "info" and higher messages to syslog:
+
+```
+log = {
+    info = "*syslog";
+    { levels = "warn", to = "sentry" };
+}
+```
+
+# Developers
+
+In addition to the automatic log forwarder, you can integrate Sentry
+forwarding directly into modules using the API.
+
+## API
+
+Usage example:
+
+```
+local sentry = module:depends("sentry").new({
+	logger = module.name;
+});
+
+sentry:event("warning")
+	:message("This is a sample warning")
+	:send();
+```
+
+### Events
+
+Event objects have a number of methods you can call to add data to them.
+All methods return the event itself, which means you can chain multiple
+calls together for convenience.
+
+After attaching all the data you want to include in the event, simply
+call `event:send()` to submit it to the server.
+
+#### set(key, value)
+
+Directly set a property of the event to the given value.
+
+#### tag(name, value)
+
+Set the specified tag to the given value.
+
+May also be called with a table of key/value pairs.
+
+#### extra(name, value)
+
+Sets the specified 'extra' data. May also be called
+with a table of key/value pairs.
+
+#### message(text)
+
+Sets the message text associated with the event.
+
+#### set_request(request)
+
+Sets the HTTP request associated with the event.
+
+This is used to indicate what incoming HTTP request
+was being processed at the time of the event.
+
+#### add_exception(e)
+
+Accepts an error object (from util.error or any arbitrary value)
+and attempts to map it to a Sentry exception.
+
+May be called multiple times on the same event, to represent
+nested exceptions (the outermost exception should be added first).
+
+#### add_breadcrumb(timestamp, type, category, message, data)
+
+Add a breadcrumb to the event. A breadcrumb represents any useful
+piece of information that led up to the event. See Sentry documentation
+for allowable types and categories.
+
+#### add_http_request_breadcrumb(request, message)
+
+Helper to add a breadcrumb representing a HTTP request that was made.
+
+The `message` parameter is an optional human-readable text description
+of the request.
+
+#### send()
+
+Sends the event to the Sentry server. Returns a promise that resolves
+to the response from the server.
diff -r 281a864e7472 -r 2ae71126e379 mod_sentry/mod_sentry.lua
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_sentry/mod_sentry.lua	Tue Dec 08 15:34:53 2020 +0000
@@ -0,0 +1,80 @@
+module:set_global();
+
+local sentry_lib = module:require "sentry";
+
+local hostname;
+local have_pposix, pposix = pcall(require, "util.pposix");
+if have_pposix and pposix.uname then
+	hostname = pposix.uname().nodename;
+end
+
+local loggingmanager = require "core.loggingmanager";
+local format = require "util.format".format;
+
+local default_config = assert(module:get_option("sentry"), "Please provide a 'sentry' configuration option");
+default_config.server_name = default_config.server_name or hostname or "prosody";
+
+local sentry = assert(sentry_lib.new(default_config));
+
+local log_filters = {
+	source = function (filter_source, name)
+		local source = name:match(":(.+)$") or name;
+		if filter_source == source then
+			return true;
+		end
+	end;
+	message_pattern = function (pattern, _, _, message)
+		return not not message:match(pattern);
+	end;
+};
+
+local function sentry_error_handler(e)
+	module:log("error", "Failed to submit event to sentry: %s", e);
+end
+
+local function sentry_log_sink_maker(sink_config)
+	local filters = sink_config.ignore or {};
+	local n_filters = #filters;
+
+	local submitting;
+	return function (name, level, message, ...)
+		-- Ignore any log messages that occur during sentry submission
+		-- to avoid loops
+		if submitting then return; end
+		for i = 1, n_filters do
+			local filter = filters[i];
+			local matched;
+			for filter_name, filter_value in pairs(filter) do
+				local f = log_filters[filter_name];
+				if f and f(filter_value, name, level, message) then
+					matched = true;
+				else
+					matched = nil;
+					break;
+				end
+			end
+			if matched then
+				return;
+			end
+		end
+		if level == "warn" then
+			level = "warning";
+		end
+
+		submitting = true;
+		sentry:event(level, name):message(format(message, ...)):send():catch(sentry_error_handler);
+		submitting = false;
+	end;
+end
+
+loggingmanager.register_sink_type("sentry", sentry_log_sink_maker);
+
+function new(conf) --luacheck: ignore 131/new
+	conf = conf or {};
+	for k, v in pairs(default_config) do
+		if conf[k] == nil then
+			conf[k] = v;
+		end
+	end
+	return sentry_lib.new(conf);
+end
diff -r 281a864e7472 -r 2ae71126e379 mod_sentry/sentry.lib.lua
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_sentry/sentry.lib.lua	Tue Dec 08 15:34:53 2020 +0000
@@ -0,0 +1,251 @@
+local hex = require "util.hex";
+local random = require "util.random";
+local url = require "socket.url";
+local datetime = require "util.datetime".datetime;
+local http = require 'net.http'
+local json = require "util.json";
+local errors = require "util.error";
+local promise = require "util.promise";
+
+local unpack = unpack or table.unpack -- luacheck: ignore
+
+local user_agent = ("prosody-mod-%s/%s"):format((module.name:gsub("%W", "-")), (prosody.version:gsub("[^%w.-]", "-")));
+
+local function generate_event_id()
+	return hex.to(random.bytes(16));
+end
+
+local function get_endpoint(server, name)
+	return ("%s/api/%d/%s/"):format(server.base_uri, server.project_id, name);
+end
+
+-- Parse a DSN string
+-- https://develop.sentry.dev/sdk/overview/#parsing-the-dsn
+local function parse_dsn(dsn_string)
+	local parsed = url.parse(dsn_string);
+	if not parsed then
+		return nil, "unable to parse dsn (url)";
+	end
+	local path, project_id = parsed.path:match("^(.*)/(%d+)$");
+	if not path then
+		return nil, "unable to parse dsn (path)";
+	end
+	local base_uri = url.build({
+		scheme = parsed.scheme;
+		host = parsed.host;
+		port = parsed.port;
+		path = path;
+	});
+	return {
+		base_uri = base_uri;
+		public_key = parsed.user;
+		project_id = project_id;
+	};
+end
+
+local function get_error_data(instance_id, context)
+	local data = {
+		instance_id = instance_id;
+	};
+	for k, v in pairs(context) do
+		data[k] = tostring(v);
+	end
+	return data;
+end
+
+local function error_to_sentry_exception(e)
+	return {
+		type = e.condition or (e.code and tostring(e.code)) or nil;
+		value = e.text or tostring(e);
+		context = e.source;
+		mechanism = {
+			type = "generic";
+			description = "Prosody error object";
+			synthetic = not not e.context.wrapped_error;
+			data = get_error_data(e.instance_id, e.context);
+		};
+	};
+end
+
+local sentry_event_methods = {};
+local sentry_event_mt = { __index = sentry_event_methods };
+
+function sentry_event_methods:set(key, value)
+	self.event[key] = value;
+	return self;
+end
+
+function sentry_event_methods:tag(tag_name, tag_value)
+	local tags = self.event.tags;
+	if not tags then
+		tags = {};
+		self.event.tags = tags;
+	end
+	if type(tag_name) == "string" then
+		tags[tag_name] = tag_value;
+	else
+		for k, v in pairs(tag_name) do
+			tags[k] = v;
+		end
+	end
+	return self;
+end
+
+function sentry_event_methods:extra(key, value)
+	local extra = self.event.extra;
+	if not extra then
+		extra = {};
+		self.event.extra = extra;
+	end
+	if type(key) == "string" then
+		extra[key] = tostring(value);
+	else
+		for k, v in pairs(key) do
+			extra[k] = tostring(v);
+		end
+	end
+	return self;
+end
+
+function sentry_event_methods:message(text)
+	return self:set("message", { formatted = text });
+end
+
+function sentry_event_methods:add_exception(e)
+	if errors.is_error(e) then
+		e = error_to_sentry_exception(e);
+	elseif type(e) ~= "table" or not (e.type and e.value) then
+		e = error_to_sentry_exception(errors.coerce(nil, e));
+	end
+
+	local exception = self.event.exception;
+	if not exception or not exception.values then
+		exception = { values = {} };
+		self.event.exception = exception;
+	end
+
+	table.insert(exception.values, e);
+
+	return self;
+end
+
+function sentry_event_methods:add_breadcrumb(crumb_timestamp, crumb_type, crumb_category, message, data)
+	local crumbs = self.event.breadcrumbs;
+	if not crumbs then
+		crumbs = { values = {} };
+		self.event.breadcrumbs = crumbs;
+	end
+
+	local crumb = {
+		timestamp = crumb_timestamp and datetime(crumb_timestamp) or self.timestamp;
+		type = crumb_type;
+		category = crumb_category;
+		message = message;
+		data = data;
+	};
+	table.insert(crumbs.values, crumb);
+	return self;
+end
+
+function sentry_event_methods:add_http_request_breadcrumb(http_request, message)
+	local request_id_message = ("[Request %s]"):format(http_request.id);
+	message = message and (request_id_message.." "..message) or request_id_message;
+	return self:add_breadcrumb(http_request.time, "http", "net.http", message, {
+		url = http_request.url;
+		method = http_request.method or "GET";
+		status_code = http_request.response and http_request.response.code or nil;
+	});
+end
+
+function sentry_event_methods:set_request(http_request)
+	return self:set("request", {
+		method = http_request.method;
+		url = url.build(http_request.url);
+		headers = http_request.headers;
+		env = {
+			REMOTE_ADDR = http_request.ip;
+		};
+	});
+end
+
+function sentry_event_methods:send()
+	return self.server:send(self.event);
+end
+
+local sentry_mt = { }
+sentry_mt.__index = sentry_mt
+
+local function new(conf)
+	local server = assert(parse_dsn(conf.dsn));
+	return setmetatable({
+		server = server;
+		endpoints = {
+			store = get_endpoint(server, "store");
+		};
+		insecure = conf.insecure;
+		tags = conf.tags or nil,
+		extra = conf.extra or nil,
+		server_name = conf.server_name or "undefined";
+		logger = conf.logger;
+	}, sentry_mt);
+end
+
+local function resolve_sentry_response(response)
+	if response.code == 200 and response.body then
+		local data = json.decode(response.body);
+		return data;
+	end
+	return promise.reject(response);
+end
+
+function sentry_mt:send(event)
+	local json_payload = json.encode(event);
+	local response_promise, err = self:_request(self.endpoints.store, "application/json", json_payload);
+
+	if not response_promise then
+		module:log("warn", "Failed to submit to Sentry: %s %s", err, json);
+		return nil, err;
+	end
+
+	return response_promise:next(resolve_sentry_response), event.event_id;
+end
+
+function sentry_mt:_request(endpoint_url, body_type, body)
+	local auth_header = ("Sentry sentry_version=7, sentry_client=%s, sentry_timestamp=%s, sentry_key=%s")
+		:format(user_agent, datetime(), self.server.public_key);
+
+	return http.request(endpoint_url, {
+		headers = {
+			["X-Sentry-Auth"] = auth_header;
+			["Content-Type"] = body_type;
+			["User-Agent"] = user_agent;
+		};
+		insecure = self.insecure;
+		body = body;
+	});
+end
+
+function sentry_mt:event(level, source)
+	local event = setmetatable({
+		server = self;
+		event = {
+			event_id = generate_event_id();
+			timestamp = datetime();
+			platform = "lua";
+			server_name = self.server_name;
+			logger = source or self.logger;
+			level = level;
+		};
+	}, sentry_event_mt);
+	if self.tags then
+		event:tag(self.tags);
+	end
+	if self.extra then
+		event:extra(self.extra);
+	end
+	return event;
+end
+
+return {
+	new = new;
+};