diff options
Diffstat (limited to 'modules/http/http.lua.in')
| -rw-r--r-- | modules/http/http.lua.in | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/modules/http/http.lua.in b/modules/http/http.lua.in new file mode 100644 index 0000000..521ddb2 --- /dev/null +++ b/modules/http/http.lua.in @@ -0,0 +1,427 @@ +-- SPDX-License-Identifier: GPL-3.0-or-later + +-- Load dependent modules +if not stats then modules.load('stats') end +if not bogus_log then modules.load('bogus_log') end + +local ffi = require('ffi') +local cqueues = require('cqueues') +cqueues.socket = require('cqueues.socket') +assert(cqueues.VERSION >= 20150112) -- fdopen changed semantics + +-- This is a module that does the heavy lifting to provide an HTTP/2 enabled +-- server that supports TLS by default and provides endpoint for other modules +-- in order to enable them to export restful APIs and websocket streams. +-- One example is statistics module that can stream live metrics on the website, +-- or publish metrics on request for Prometheus scraper. +local http_server = require('http.server') +local http_headers = require('http.headers') +local http_websocket = require('http.websocket') +local http_util = require "http.util" +local has_mmdb, mmdb = pcall(require, 'mmdb') + +-- A sub-module for certificate management. +local tls_cert = require('kres_modules.http_tls_cert') + +-- Module declaration +local M = { + servers = {}, + configs = { _builtin = {} } -- configuration templates +} + +-- inherited by all configurations +M.configs._builtin._all = { + cq = worker.bg_worker.cq, + cert = 'self.crt', + key = 'self.key', + ephemeral = true, + client_timeout = 5 +} +-- log errors but do not throw +M.configs._builtin._all.onerror = function(myserver, context, op, err, errno) -- luacheck: ignore 212 + local msg = '[http] ' .. op .. ' on ' .. tostring(context) .. ' failed' + if err then + msg = msg .. ': ' .. tostring(err) + end + if verbose() then + log(msg) + end +end + +-- M.config() without explicit "kind" modifies this +M.configs._all = {} + +-- DoH +M.configs._builtin.doh = {} + +-- management endpoint +M.configs._builtin.webmgmt = {} + +-- Map extensions to MIME type +local mime_types = { + js = 'application/javascript', + css = 'text/css', + tpl = 'text/html', + ico = 'image/x-icon' +} + +-- Preload static contents, nothing on runtime will touch the disk +local function pgload(relpath, modname) + if not modname then modname = 'http' end + local fp, err = io.open(string.format( + '@modules_dir@/%s/%s', modname, relpath), 'r') + if not fp then + fp, err = io.open(string.format( + '@modules_dir@/%s/static/%s', modname, relpath), 'r') + end + if not fp then error(err) end + local data = fp:read('*all') + fp:close() + -- Guess content type + local ext = relpath:match('[^\\.]+$') + return {mime_types[ext] or 'text', data, nil, 86400} +end +M.page = pgload + +-- Preloaded static assets +local pages = { + 'favicon.ico', + 'kresd.js', + 'kresd.css', + 'jquery.js', + 'd3.js', + 'topojson.js', + 'datamaps.world.min.js', + 'dygraph.min.js', + 'selectize.min.js', + 'selectize.bootstrap3.css', + 'bootstrap.min.js', + 'bootstrap.min.css', + 'bootstrap-theme.min.css', + 'glyphicons-halflings-regular.woff2', +} + +-- Serve preloaded root page +local function serve_root() + local data = pgload('main.tpl')[2] + data = data + :gsub('{{ title }}', M.title or ('kresd @ ' .. hostname())) + :gsub('{{ host }}', hostname()) + return function (_, _) + -- Render snippets + local rsnippets = {} + for _,v in pairs(M.snippets) do + local sid = string.lower(string.gsub(v[1], ' ', '-')) + table.insert(rsnippets, string.format('<section id="%s"><h2>%s</h2>\n%s</section>', sid, v[1], v[2])) + end + -- Return index page + return data + :gsub('{{ snippets }}', table.concat(rsnippets, '\n')) + end +end + +-- Export HTTP service endpoints +M.configs._builtin.doh.endpoints = {} +M.configs._builtin.webmgmt.endpoints = {} +local mgmt_endpoints = M.configs._builtin.webmgmt.endpoints + +mgmt_endpoints['/'] = {'text/html', serve_root()} + +-- Export static pages +for _, pg in ipairs(pages) do + mgmt_endpoints['/'..pg] = pgload(pg) +end + +-- Export built-in prometheus interface +local prometheus = require('kres_modules.prometheus') +for k, v in pairs(prometheus.endpoints) do + mgmt_endpoints[k] = v +end +M.prometheus = prometheus + +-- Export built-in trace interface +local http_trace = require('kres_modules.http_trace') +for k, v in pairs(http_trace.endpoints) do + mgmt_endpoints[k] = v +end +M.trace = http_trace + +M.configs._builtin.doh.endpoints = {} +local http_doh = require('kres_modules.http_doh') +for k, v in pairs(http_doh.endpoints) do + mgmt_endpoints[k] = v + M.configs._builtin.doh.endpoints[k] = v +end +M.doh = http_doh + +-- Export HTTP service page snippets +M.snippets = {} + +-- Serve known requests, for methods other than GET +-- the endpoint must be a closure and not a preloaded string +local function serve(endpoints, h, stream) + local hsend = http_headers.new() + local path = h:get(':path') + local entry = endpoints[path] + if not entry then -- Accept top-level path match + entry = endpoints[path:match '^/[^/?]*'] + end + -- Unpack MIME and data + local data, mime, ttl, any_origin, err + if entry then + mime = entry[1] + data = entry[2] + ttl = entry[4] + any_origin = entry[5] + end + -- Get string data out of service endpoint + if type(data) == 'function' then + local set_mime, set_ttl + data, err, set_mime, set_ttl = data(h, stream) + -- Override default endpoint mime/TTL + if set_mime then mime = set_mime end + if set_ttl then ttl = set_ttl end + -- Handler doesn't provide any data + if data == false then return end + if type(data) == 'number' then return tostring(data), err end + -- Methods other than GET require handler to be closure + elseif h:get(':method') ~= 'GET' then + return '501', '' + end + if type(data) == 'table' then data = tojson(data) end + if not mime or type(data) ~= 'string' then + return '404', '' + else + -- Serve content type appropriately + hsend:append(':status', '200') + hsend:append('content-type', mime) + hsend:append('content-length', tostring(#data)) + if ttl then + hsend:append('cache-control', string.format('max-age=%d', ttl)) + end + if any_origin then + hsend:append('access-control-allow-origin', '*') + end + assert(stream:write_headers(hsend, false)) + assert(stream:write_chunk(data, true)) + end +end + +-- Web server service closure +local function route(endpoints) + assert(type(endpoints) == 'table', 'endpoints are not a table, is it a botched template?') + return function (_, stream) + -- HTTP/2: We're only permitted to send in open/half-closed (remote) + local connection = stream.connection + if connection.version >= 2 then + if stream.state ~= 'open' and stream.state ~= 'half closed (remote)' then + return + end + end + -- Start reading headers + local h = assert(stream:get_headers()) + local m = h:get(':method') + local path = h:get(':path') + + -- Upgrade connection to WebSocket + local ws = http_websocket.new_from_stream(stream, h) + if ws then + if verbose() then + log('[http] %s %s HTTP/%d web socket open', + m, path, connection.version) + end + assert(ws:accept { protocols = {'json'} }) + -- Continue streaming results to client + local ep = endpoints[path] + local cb = ep[3] + if cb then + cb(h, ws) + end + ws:close() + if verbose() then + log('[http] %s %s HTTP/%d web socket closed', + m, path, connection.version) + end + return + else + local ok, err, reason = http_util.yieldable_pcall(serve, endpoints, h, stream) + if not ok or err then + err = err or '500' + if verbose() then + log('[http] %s %s HTTTP/%d %s %s', + m, path, connection.version, err, reason or '') + end + -- Method is not supported + local hsend = http_headers.new() + hsend:append(':status', err) + if reason then + assert(stream:write_headers(hsend, false)) + assert(stream:write_chunk(reason, true)) + else + assert(stream:write_headers(hsend, true)) + end + else if verbose() then + log('[http] %s %s HTTP/%d 200', + m, path, connection.version) + end + end + + end + end +end + +-- @function Merge dictionaries, nil is like empty dict. +-- Values from right-hand side dictionaries take precedence. +local function mergeconf(...) + local merged = {} + local ntables = select('#', ...) + local tables = {...} + for i = 1, ntables do + local intable = tables[i] + if intable ~= nil then + assert(type(intable) == 'table', 'cannot merge non-tables') + for key, val in pairs(intable) do + merged[key] = val + end + end + end + return merged +end + +-- @function Listen on given socket +-- using configuration for specific "kind" of HTTP server +local function add_socket(fd, kind, addr_str) + assert(M.servers[fd] == nil, 'socket is already served by an HTTP instance') + local conf = mergeconf(M.configs._builtin._all, M.configs._builtin[kind], + M.configs._all, M.configs[kind]) + conf.socket = cqueues.socket.fdopen({ fd = fd, reuseport = true, reuseaddr = true }) + if conf.tls ~= false then -- Create a TLS context, either from files or new. + if conf.ephemeral then + if not M.ephem_state then + M.ephem_state = { servers = M.servers } + tls_cert.ephemeral_state_maintain(M.ephem_state, conf.cert, conf.key) + end + conf.ctx = M.ephem_state.ctx + else + local certs, key = tls_cert.load(conf.cert, conf.key) + conf.ctx = tls_cert.new_tls_context(certs, key) + end + assert(conf.ctx) + end + -- Compose server handler + local routes = route(conf.endpoints) + conf.onstream = routes + -- Create TLS context and start listening + local s, err = http_server.new(conf) + -- Manually call :listen() so that we are bound before calling :localname() + if s then + err = select(2, s:listen()) + end + if err then + panic('failed to listen on %s: %s', addr_str, err) + end + M.servers[fd] = {kind = kind, server = s, config = conf} +end + +-- @function Stop listening on given socket +local function remove_socket(fd) + local instance = M.servers[fd] + assert(instance, 'HTTP module is not listening on given socket') + + instance.server:close() + M.servers[fd] = nil +end + +-- @function Listen for config changes from net.listen()/net.close() +local function cb_socket(...) + local added, endpoint, addr_str = unpack({...}) + endpoint = ffi.cast('struct endpoint **', endpoint)[0] + local kind = ffi.string(endpoint.flags.kind) + local socket = endpoint.fd + if added then + return add_socket(socket, kind, addr_str) + else + return remove_socket(socket) + end +end + +-- @function Init module +function M.init() + net.register_endpoint_kind('doh', cb_socket) + net.register_endpoint_kind('webmgmt', cb_socket) +end + +-- @function Cleanup module +function M.deinit() + for fd, _ in pairs(M.servers) do + remove_socket(fd) + end + tls_cert.ephemeral_state_destroy(M.ephem_state) + net.register_endpoint_kind('doh') + net.register_endpoint_kind('webmgmt') +end + +-- @function Configure module, i.e. store new configuration template +-- kind = socket type (doh/webmgmt) +function M.config(conf, kind) + if conf == nil and kind == nil then + -- default module config, nothing to do + return + end + + kind = kind or '_all' + assert(type(kind) == 'string') + + local operation + -- builtins cannot be removed or added + if M.configs._builtin[kind] then + operation = 'modify' + conf = conf or {} + elseif M.configs[kind] then -- config on an existing user template + if conf then operation = 'modify' + else operation = 'delete' end + else -- config for not-yet-existing template + if conf then operation = 'add' + else panic('[http] endpoint kind "%s" does not exist, ' + .. 'nothing to delete', kind) end + end + + if operation == 'modify' or operation == 'add' then + assert(type(conf) == 'table', 'config { cert = "...", key = "..." }') + + if conf.cert then + conf.ephemeral = false + if not conf.key then + panic('[http] certificate provided, but missing key') + end + -- test if it can be loaded or not + tls_cert.load(conf.cert, conf.key) + end + if conf.geoip then + if has_mmdb then + M.geoip = mmdb.open(conf.geoip) + else + error('[http] mmdblua library not found, please remove GeoIP configuration') + end + end + end + + for _, instance in pairs(M.servers) do + -- modification cannot be implemented as + -- remove_socket + add_socket because remove closes the socket + if instance.kind == kind or kind == '_all' then + panic('unable to modify configration for ' + .. 'endpoint kind "%s" because it is in ' + .. 'use, use net.close() first', kind) + end + end + + if operation == 'add' then + net.register_endpoint_kind(kind, cb_socket) + elseif operation == 'delete' then + net.register_endpoint_kind(kind) + end + M.configs[kind] = conf +end + +return M |