streaming/index.js
// @ts-check
const fs = require('fs');
const http = require('http');
const url = require('url');
const dotenv = require('dotenv');
const express = require('express');
const Redis = require('ioredis');
const { JSDOM } = require('jsdom');
const log = require('npmlog');
const pg = require('pg');
const dbUrlToConfig = require('pg-connection-string').parse;
const metrics = require('prom-client');
const uuid = require('uuid');
const WebSocket = require('ws');
const environment = process.env.NODE_ENV || 'development';
dotenv.config({
path: environment === 'production' ? '.env.production' : '.env',
});
log.level = process.env.LOG_LEVEL || 'verbose';
/**
* @param {Object.<string, any>} config
*/
const createRedisClient = async (config) => {
const { redisParams, redisUrl } = config;
const client = new Redis(redisUrl, redisParams);
client.on('error', (err) => log.error('Redis Client Error!', err));
return client;
};
/**
* Attempts to safely parse a string as JSON, used when both receiving a message
* from redis and when receiving a message from a client over a websocket
* connection, this is why it accepts a `req` argument.
* @param {string} json
* @param {any?} req
* @returns {Object.<string, any>|null}
*/
const parseJSON = (json, req) => {
try {
return JSON.parse(json);
} catch (err) {
/* FIXME: This logging isn't great, and should probably be done at the
* call-site of parseJSON, not in the method, but this would require changing
* the signature of parseJSON to return something akin to a Result type:
* [Error|null, null|Object<string,any}], and then handling the error
* scenarios.
*/
if (req) {
if (req.accountId) {
log.warn(req.requestId, `Error parsing message from user ${req.accountId}: ${err}`);
} else {
log.silly(req.requestId, `Error parsing message from ${req.remoteAddress}: ${err}`);
}
} else {
log.warn(`Error parsing message from redis: ${err}`);
}
return null;
}
};
/**
* @param {Object.<string, any>} env the `process.env` value to read configuration from
* @returns {Object.<string, any>} the configuration for the PostgreSQL connection
*/
const pgConfigFromEnv = (env) => {
const pgConfigs = {
development: {
user: env.DB_USER || pg.defaults.user,
password: env.DB_PASS || pg.defaults.password,
database: env.DB_NAME || 'mastodon_development',
host: env.DB_HOST || pg.defaults.host,
port: env.DB_PORT || pg.defaults.port,
},
production: {
user: env.DB_USER || 'mastodon',
password: env.DB_PASS || '',
database: env.DB_NAME || 'mastodon_production',
host: env.DB_HOST || 'localhost',
port: env.DB_PORT || 5432,
},
};
let baseConfig;
if (env.DATABASE_URL) {
baseConfig = dbUrlToConfig(env.DATABASE_URL);
// Support overriding the database password in the connection URL
if (!baseConfig.password && env.DB_PASS) {
baseConfig.password = env.DB_PASS;
}
} else {
baseConfig = pgConfigs[environment];
if (env.DB_SSLMODE) {
switch(env.DB_SSLMODE) {
case 'disable':
case '':
baseConfig.ssl = false;
break;
case 'no-verify':
baseConfig.ssl = { rejectUnauthorized: false };
break;
default:
baseConfig.ssl = {};
break;
}
}
}
return {
...baseConfig,
max: env.DB_POOL || 10,
connectionTimeoutMillis: 15000,
application_name: '',
};
};
/**
* @param {Object.<string, any>} env the `process.env` value to read configuration from
* @returns {Object.<string, any>} configuration for the Redis connection
*/
const redisConfigFromEnv = (env) => {
// ioredis *can* transparently add prefixes for us, but it doesn't *in some cases*,
// which means we can't use it. But this is something that should be looked into.
const redisPrefix = env.REDIS_NAMESPACE ? `${env.REDIS_NAMESPACE}:` : '';
const redisParams = {
host: env.REDIS_HOST || '127.0.0.1',
port: env.REDIS_PORT || 6379,
db: env.REDIS_DB || 0,
password: env.REDIS_PASSWORD || undefined,
};
// redisParams.path takes precedence over host and port.
if (env.REDIS_URL && env.REDIS_URL.startsWith('unix://')) {
redisParams.path = env.REDIS_URL.slice(7);
}
return {
redisParams,
redisPrefix,
redisUrl: env.REDIS_URL,
};
};
const PUBLIC_CHANNELS = [
'public',
'public:media',
'public:local',
'public:local:media',
'public:remote',
'public:remote:media',
'hashtag',
'hashtag:local',
];
// Used for priming the counters/gauges for the various metrics that are
// per-channel
const CHANNEL_NAMES = [
'system',
'user',
'user:notification',
'list',
'direct',
...PUBLIC_CHANNELS
];
const startServer = async () => {
const app = express();
app.set('trust proxy', process.env.TRUSTED_PROXY_IP ? process.env.TRUSTED_PROXY_IP.split(/(?:\s*,\s*|\s+)/) : 'loopback,uniquelocal');
const pgPool = new pg.Pool(pgConfigFromEnv(process.env));
const server = http.createServer(app);
/**
* @type {Object.<string, Array.<function(Object<string, any>): void>>}
*/
const subs = {};
const redisConfig = redisConfigFromEnv(process.env);
const redisSubscribeClient = await createRedisClient(redisConfig);
const redisClient = await createRedisClient(redisConfig);
const { redisPrefix } = redisConfig;
// Collect metrics from Node.js
metrics.collectDefaultMetrics();
new metrics.Gauge({
name: 'pg_pool_total_connections',
help: 'The total number of clients existing within the pool',
collect() {
this.set(pgPool.totalCount);
},
});
new metrics.Gauge({
name: 'pg_pool_idle_connections',
help: 'The number of clients which are not checked out but are currently idle in the pool',
collect() {
this.set(pgPool.idleCount);
},
});
new metrics.Gauge({
name: 'pg_pool_waiting_queries',
help: 'The number of queued requests waiting on a client when all clients are checked out',
collect() {
this.set(pgPool.waitingCount);
},
});
const connectedClients = new metrics.Gauge({
name: 'connected_clients',
help: 'The number of clients connected to the streaming server',
labelNames: ['type'],
});
const connectedChannels = new metrics.Gauge({
name: 'connected_channels',
help: 'The number of channels the streaming server is streaming to',
labelNames: [ 'type', 'channel' ]
});
const redisSubscriptions = new metrics.Gauge({
name: 'redis_subscriptions',
help: 'The number of Redis channels the streaming server is subscribed to',
});
const redisMessagesReceived = new metrics.Counter({
name: 'redis_messages_received_total',
help: 'The total number of messages the streaming server has received from redis subscriptions'
});
const messagesSent = new metrics.Counter({
name: 'messages_sent_total',
help: 'The total number of messages the streaming server sent to clients per connection type',
labelNames: [ 'type' ]
});
// Prime the gauges so we don't loose metrics between restarts:
redisSubscriptions.set(0);
connectedClients.set({ type: 'websocket' }, 0);
connectedClients.set({ type: 'eventsource' }, 0);
// For each channel, initialize the gauges at zero; There's only a finite set of channels available
CHANNEL_NAMES.forEach(( channel ) => {
connectedChannels.set({ type: 'websocket', channel }, 0);
connectedChannels.set({ type: 'eventsource', channel }, 0);
})
// Prime the counters so that we don't loose metrics between restarts.
// Unfortunately counters don't support the set() API, so instead I'm using
// inc(0) to achieve the same result.
redisMessagesReceived.inc(0);
messagesSent.inc({ type: 'websocket' }, 0);
messagesSent.inc({ type: 'eventsource' }, 0);
// When checking metrics in the browser, the favicon is requested this
// prevents the request from falling through to the API Router, which would
// error for this endpoint:
app.get('/favicon.ico', (req, res) => res.status(404).end());
app.get('/api/v1/streaming/health', (req, res) => {
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('OK');
});
app.get('/metrics', async (req, res) => {
try {
res.set('Content-Type', metrics.register.contentType);
res.end(await metrics.register.metrics());
} catch (ex) {
log.error(ex);
res.status(500).end();
}
});
/**
* @param {string[]} channels
* @returns {function(): void}
*/
const subscriptionHeartbeat = channels => {
const interval = 6 * 60;
const tellSubscribed = () => {
channels.forEach(channel => redisClient.set(`${redisPrefix}subscribed:${channel}`, '1', 'EX', interval * 3));
};
tellSubscribed();
const heartbeat = setInterval(tellSubscribed, interval * 1000);
return () => {
clearInterval(heartbeat);
};
};
/**
* @param {string} channel
* @param {string} message
*/
const onRedisMessage = (channel, message) => {
redisMessagesReceived.inc();
const callbacks = subs[channel];
log.silly(`New message on channel ${redisPrefix}${channel}`);
if (!callbacks) {
return;
}
const json = parseJSON(message, null);
if (!json) return;
callbacks.forEach(callback => callback(json));
};
redisSubscribeClient.on("message", onRedisMessage);
/**
* @callback SubscriptionListener
* @param {ReturnType<parseJSON>} json of the message
* @returns void
*/
/**
* @callback SubscriptionListener
* @param {ReturnType<parseJSON>} json of the message
* @returns void
*/
/**
* @param {string} channel
* @param {SubscriptionListener} callback
*/
const subscribe = (channel, callback) => {
log.silly(`Adding listener for ${channel}`);
subs[channel] = subs[channel] || [];
if (subs[channel].length === 0) {
log.verbose(`Subscribe ${channel}`);
redisSubscribeClient.subscribe(channel, (err, count) => {
if (err) {
log.error(`Error subscribing to ${channel}`);
}
else {
redisSubscriptions.set(count);
}
});
}
subs[channel].push(callback);
};
/**
* @param {string} channel
* @param {SubscriptionListener} callback
*/
const unsubscribe = (channel, callback) => {
log.silly(`Removing listener for ${channel}`);
if (!subs[channel]) {
return;
}
subs[channel] = subs[channel].filter(item => item !== callback);
if (subs[channel].length === 0) {
log.verbose(`Unsubscribe ${channel}`);
redisSubscribeClient.unsubscribe(channel, (err, count) => {
if (err) {
log.error(`Error unsubscribing to ${channel}`);
}
else {
redisSubscriptions.set(count);
}
});
delete subs[channel];
}
};
const FALSE_VALUES = [
false,
0,
'0',
'f',
'F',
'false',
'FALSE',
'off',
'OFF',
];
/**
* @param {any} value
* @returns {boolean}
*/
const isTruthy = value =>
value && !FALSE_VALUES.includes(value);
/**
* @param {any} req
* @param {any} res
* @param {function(Error=): void} next
*/
const allowCrossDomain = (req, res, next) => {
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Headers', 'Authorization, Accept, Cache-Control');
res.header('Access-Control-Allow-Methods', 'GET, OPTIONS');
next();
};
/**
* @param {any} req
* @param {any} res
* @param {function(Error=): void} next
*/
const setRequestId = (req, res, next) => {
req.requestId = uuid.v4();
res.header('X-Request-Id', req.requestId);
next();
};
/**
* @param {any} req
* @param {any} res
* @param {function(Error=): void} next
*/
const setRemoteAddress = (req, res, next) => {
req.remoteAddress = req.connection.remoteAddress;
next();
};
/**
* @param {any} req
* @param {string[]} necessaryScopes
* @returns {boolean}
*/
const isInScope = (req, necessaryScopes) =>
req.scopes.some(scope => necessaryScopes.includes(scope));
/**
* @param {string} token
* @param {any} req
* @returns {Promise.<void>}
*/
const accountFromToken = (token, req) => new Promise((resolve, reject) => {
pgPool.connect((err, client, done) => {
if (err) {
reject(err);
return;
}
client.query('SELECT oauth_access_tokens.id, oauth_access_tokens.resource_owner_id, users.account_id, users.chosen_languages, oauth_access_tokens.scopes, devices.device_id FROM oauth_access_tokens INNER JOIN users ON oauth_access_tokens.resource_owner_id = users.id LEFT OUTER JOIN devices ON oauth_access_tokens.id = devices.access_token_id WHERE oauth_access_tokens.token = $1 AND oauth_access_tokens.revoked_at IS NULL LIMIT 1', [token], (err, result) => {
done();
if (err) {
reject(err);
return;
}
if (result.rows.length === 0) {
err = new Error('Invalid access token');
err.status = 401;
reject(err);
return;
}
req.accessTokenId = result.rows[0].id;
req.scopes = result.rows[0].scopes.split(' ');
req.accountId = result.rows[0].account_id;
req.chosenLanguages = result.rows[0].chosen_languages;
req.deviceId = result.rows[0].device_id;
resolve();
});
});
});
/**
* @param {any} req
* @returns {Promise.<void>}
*/
const accountFromRequest = (req) => new Promise((resolve, reject) => {
const authorization = req.headers.authorization;
const location = url.parse(req.url, true);
const accessToken = location.query.access_token || req.headers['sec-websocket-protocol'];
if (!authorization && !accessToken) {
const err = new Error('Missing access token');
err.status = 401;
reject(err);
return;
}
const token = authorization ? authorization.replace(/^Bearer /, '') : accessToken;
resolve(accountFromToken(token, req));
});
/**
* @param {any} req
* @returns {string|undefined}
*/
const channelNameFromPath = req => {
const { path, query } = req;
const onlyMedia = isTruthy(query.only_media);
switch (path) {
case '/api/v1/streaming/user':
return 'user';
case '/api/v1/streaming/user/notification':
return 'user:notification';
case '/api/v1/streaming/public':
return onlyMedia ? 'public:media' : 'public';
case '/api/v1/streaming/public/local':
return onlyMedia ? 'public:local:media' : 'public:local';
case '/api/v1/streaming/public/remote':
return onlyMedia ? 'public:remote:media' : 'public:remote';
case '/api/v1/streaming/hashtag':
return 'hashtag';
case '/api/v1/streaming/hashtag/local':
return 'hashtag:local';
case '/api/v1/streaming/direct':
return 'direct';
case '/api/v1/streaming/list':
return 'list';
default:
return undefined;
}
};
/**
* @param {any} req
* @param {string|undefined} channelName
* @returns {Promise.<void>}
*/
const checkScopes = (req, channelName) => new Promise((resolve, reject) => {
log.silly(req.requestId, `Checking OAuth scopes for ${channelName}`);
// When accessing public channels, no scopes are needed
if (PUBLIC_CHANNELS.includes(channelName)) {
resolve();
return;
}
// The `read` scope has the highest priority, if the token has it
// then it can access all streams
const requiredScopes = ['read'];
// When accessing specifically the notifications stream,
// we need a read:notifications, while in all other cases,
// we can allow access with read:statuses. Mind that the
// user stream will not contain notifications unless
// the token has either read or read:notifications scope
// as well, this is handled separately.
if (channelName === 'user:notification') {
requiredScopes.push('read:notifications');
} else {
requiredScopes.push('read:statuses');
}
if (req.scopes && requiredScopes.some(requiredScope => req.scopes.includes(requiredScope))) {
resolve();
return;
}
const err = new Error('Access token does not cover required scopes');
err.status = 401;
reject(err);
});
/**
* @param {any} info
* @param {function(boolean, number, string): void} callback
*/
const wsVerifyClient = (info, callback) => {
// When verifying the websockets connection, we no longer pre-emptively
// check OAuth scopes and drop the connection if they're missing. We only
// drop the connection if access without token is not allowed by environment
// variables. OAuth scope checks are moved to the point of subscription
// to a specific stream.
accountFromRequest(info.req).then(() => {
callback(true, undefined, undefined);
}).catch(err => {
log.error(info.req.requestId, err.toString());
callback(false, 401, 'Unauthorized');
});
};
/**
* @typedef SystemMessageHandlers
* @property {function(): void} onKill
*/
/**
* @param {any} req
* @param {SystemMessageHandlers} eventHandlers
* @returns {function(object): void}
*/
const createSystemMessageListener = (req, eventHandlers) => {
return message => {
const { event } = message;
log.silly(req.requestId, `System message for ${req.accountId}: ${event}`);
if (event === 'kill') {
log.verbose(req.requestId, `Closing connection for ${req.accountId} due to expired access token`);
eventHandlers.onKill();
} else if (event === 'filters_changed') {
log.verbose(req.requestId, `Invalidating filters cache for ${req.accountId}`);
req.cachedFilters = null;
}
};
};
/**
* @param {any} req
* @param {any} res
*/
const subscribeHttpToSystemChannel = (req, res) => {
const accessTokenChannelId = `timeline:access_token:${req.accessTokenId}`;
const systemChannelId = `timeline:system:${req.accountId}`;
const listener = createSystemMessageListener(req, {
onKill() {
res.end();
},
});
res.on('close', () => {
unsubscribe(`${redisPrefix}${accessTokenChannelId}`, listener);
unsubscribe(`${redisPrefix}${systemChannelId}`, listener);
connectedChannels.labels({ type: 'eventsource', channel: 'system' }).dec(2);
});
subscribe(`${redisPrefix}${accessTokenChannelId}`, listener);
subscribe(`${redisPrefix}${systemChannelId}`, listener);
connectedChannels.labels({ type: 'eventsource', channel: 'system' }).inc(2);
};
/**
* @param {any} req
* @param {any} res
* @param {function(Error=): void} next
*/
const authenticationMiddleware = (req, res, next) => {
if (req.method === 'OPTIONS') {
next();
return;
}
const channelName = channelNameFromPath(req);
// If no channelName can be found for the request, then we should terminate
// the connection, as there's nothing to stream back
if (!channelName) {
const err = new Error('Unknown channel requested');
err.status = 400;
next(err);
return;
}
accountFromRequest(req).then(() => checkScopes(req, channelName)).then(() => {
subscribeHttpToSystemChannel(req, res);
}).then(() => {
next();
}).catch(err => {
next(err);
});
};
/**
* @param {Error} err
* @param {any} req
* @param {any} res
* @param {function(Error=): void} next
*/
const errorMiddleware = (err, req, res, next) => {
log.error(req.requestId, err.toString());
if (res.headersSent) {
next(err);
return;
}
res.writeHead(err.status || 500, { 'Content-Type': 'application/json' });
res.end(JSON.stringify({ error: err.status ? err.toString() : 'An unexpected error occurred' }));
};
/**
* @param {array} arr
* @param {number=} shift
* @returns {string}
*/
const placeholders = (arr, shift = 0) => arr.map((_, i) => `$${i + 1 + shift}`).join(', ');
/**
* @param {string} listId
* @param {any} req
* @returns {Promise.<void>}
*/
const authorizeListAccess = (listId, req) => new Promise((resolve, reject) => {
const { accountId } = req;
pgPool.connect((err, client, done) => {
if (err) {
reject();
return;
}
client.query('SELECT id, account_id FROM lists WHERE id = $1 LIMIT 1', [listId], (err, result) => {
done();
if (err || result.rows.length === 0 || result.rows[0].account_id !== accountId) {
reject();
return;
}
resolve();
});
});
});
/**
* @param {string[]} ids
* @param {any} req
* @param {function(string, string): void} output
* @param {undefined | function(string[], SubscriptionListener): void} attachCloseHandler
* @param {'websocket' | 'eventsource'} destinationType
* @param {boolean=} needsFiltering
* @returns {SubscriptionListener}
*/
const streamFrom = (ids, req, output, attachCloseHandler, destinationType, needsFiltering = false) => {
const accountId = req.accountId || req.remoteAddress;
log.verbose(req.requestId, `Starting stream from ${ids.join(', ')} for ${accountId}`);
const transmit = (event, payload) => {
// TODO: Replace "string"-based delete payloads with object payloads:
const encodedPayload = typeof payload === 'object' ? JSON.stringify(payload) : payload;
messagesSent.labels({ type: destinationType }).inc(1);
log.silly(req.requestId, `Transmitting for ${accountId}: ${event} ${encodedPayload}`);
output(event, encodedPayload);
};
// The listener used to process each message off the redis subscription,
// message here is an object with an `event` and `payload` property. Some
// events also include a queued_at value, but this is being removed shortly.
/** @type {SubscriptionListener} */
const listener = message => {
const { event, payload } = message;
// Streaming only needs to apply filtering to some channels and only to
// some events. This is because majority of the filtering happens on the
// Ruby on Rails side when producing the event for streaming.
//
// The only events that require filtering from the streaming server are
// `update` and `status.update`, all other events are transmitted to the
// client as soon as they're received (pass-through).
//
// The channels that need filtering are determined in the function
// `channelNameToIds` defined below:
if (!needsFiltering || (event !== 'update' && event !== 'status.update')) {
transmit(event, payload);
return;
}
// The rest of the logic from here on in this function is to handle
// filtering of statuses:
// Filter based on language:
if (Array.isArray(req.chosenLanguages) && payload.language !== null && req.chosenLanguages.indexOf(payload.language) === -1) {
log.silly(req.requestId, `Message ${payload.id} filtered by language (${payload.language})`);
return;
}
// When the account is not logged in, it is not necessary to confirm the block or mute
if (!req.accountId) {
transmit(event, payload);
return;
}
// Filter based on domain blocks, blocks, mutes, or custom filters:
const targetAccountIds = [payload.account.id].concat(payload.mentions.map(item => item.id));
const accountDomain = payload.account.acct.split('@')[1];
// TODO: Move this logic out of the message handling loop
pgPool.connect((err, client, releasePgConnection) => {
if (err) {
log.error(err);
return;
}
const queries = [
client.query(`SELECT 1
FROM blocks
WHERE (account_id = $1 AND target_account_id IN (${placeholders(targetAccountIds, 2)}))
OR (account_id = $2 AND target_account_id = $1)
UNION
SELECT 1
FROM mutes
WHERE account_id = $1
AND target_account_id IN (${placeholders(targetAccountIds, 2)})`, [req.accountId, payload.account.id].concat(targetAccountIds)),
];
if (accountDomain) {
queries.push(client.query('SELECT 1 FROM account_domain_blocks WHERE account_id = $1 AND domain = $2', [req.accountId, accountDomain]));
}
if (!payload.filtered && !req.cachedFilters) {
queries.push(client.query('SELECT filter.id AS id, filter.phrase AS title, filter.context AS context, filter.expires_at AS expires_at, filter.action AS filter_action, keyword.keyword AS keyword, keyword.whole_word AS whole_word FROM custom_filter_keywords keyword JOIN custom_filters filter ON keyword.custom_filter_id = filter.id WHERE filter.account_id = $1 AND (filter.expires_at IS NULL OR filter.expires_at > NOW())', [req.accountId]));
}
Promise.all(queries).then(values => {
releasePgConnection();
// Handling blocks & mutes and domain blocks: If one of those applies,
// then we don't transmit the payload of the event to the client
if (values[0].rows.length > 0 || (accountDomain && values[1].rows.length > 0)) {
return;
}
// If the payload already contains the `filtered` property, it means
// that filtering has been applied on the ruby on rails side, as
// such, we don't need to construct or apply the filters in streaming:
if (Object.prototype.hasOwnProperty.call(payload, "filtered")) {
transmit(event, payload);
return;
}
// Handling for constructing the custom filters and caching them on the request
// TODO: Move this logic out of the message handling lifecycle
if (!req.cachedFilters) {
const filterRows = values[accountDomain ? 2 : 1].rows;
req.cachedFilters = filterRows.reduce((cache, filter) => {
if (cache[filter.id]) {
cache[filter.id].keywords.push([filter.keyword, filter.whole_word]);
} else {
cache[filter.id] = {
keywords: [[filter.keyword, filter.whole_word]],
expires_at: filter.expires_at,
filter: {
id: filter.id,
title: filter.title,
context: filter.context,
expires_at: filter.expires_at,
// filter.filter_action is the value from the
// custom_filters.action database column, it is an integer
// representing a value in an enum defined by Ruby on Rails:
//
// enum { warn: 0, hide: 1 }
filter_action: ['warn', 'hide'][filter.filter_action],
},
};
}
return cache;
}, {});
// Construct the regular expressions for the custom filters: This
// needs to be done in a separate loop as the database returns one
// filterRow per keyword, so we need all the keywords before
// constructing the regular expression
Object.keys(req.cachedFilters).forEach((key) => {
req.cachedFilters[key].regexp = new RegExp(req.cachedFilters[key].keywords.map(([keyword, whole_word]) => {
let expr = keyword.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
if (whole_word) {
if (/^[\w]/.test(expr)) {
expr = `\\b${expr}`;
}
if (/[\w]$/.test(expr)) {
expr = `${expr}\\b`;
}
}
return expr;
}).join('|'), 'i');
});
}
// Apply cachedFilters against the payload, constructing a
// `filter_results` array of FilterResult entities
if (req.cachedFilters) {
const status = payload;
// TODO: Calculate searchableContent in Ruby on Rails:
const searchableContent = ([status.spoiler_text || '', status.content].concat((status.poll && status.poll.options) ? status.poll.options.map(option => option.title) : [])).concat(status.media_attachments.map(att => att.description)).join('\n\n').replace(/<br\s*\/?>/g, '\n').replace(/<\/p><p>/g, '\n\n');
const searchableTextContent = JSDOM.fragment(searchableContent).textContent;
const now = new Date();
const filter_results = Object.values(req.cachedFilters).reduce((results, cachedFilter) => {
// Check the filter hasn't expired before applying:
if (cachedFilter.expires_at !== null && cachedFilter.expires_at < now) {
return results;
}
// Just in-case JSDOM fails to find textContent in searchableContent
if (!searchableTextContent) {
return results;
}
const keyword_matches = searchableTextContent.match(cachedFilter.regexp);
if (keyword_matches) {
// results is an Array of FilterResult; status_matches is always
// null as we only are only applying the keyword-based custom
// filters, not the status-based custom filters.
// https://docs.joinmastodon.org/entities/FilterResult/
results.push({
filter: cachedFilter.filter,
keyword_matches,
status_matches: null
});
}
return results;
}, []);
// Send the payload + the FilterResults as the `filtered` property
// to the streaming connection. To reach this code, the `event` must
// have been either `update` or `status.update`, meaning the
// `payload` is a Status entity, which has a `filtered` property:
//
// filtered: https://docs.joinmastodon.org/entities/Status/#filtered
transmit(event, {
...payload,
filtered: filter_results
});
} else {
transmit(event, payload);
}
}).catch(err => {
releasePgConnection();
log.error(err);
releasePgConnection();
});
});
};
ids.forEach(id => {
subscribe(`${redisPrefix}${id}`, listener);
});
if (typeof attachCloseHandler === 'function') {
attachCloseHandler(ids.map(id => `${redisPrefix}${id}`), listener);
}
return listener;
};
/**
* @param {any} req
* @param {any} res
* @returns {function(string, string): void}
*/
const streamToHttp = (req, res) => {
const accountId = req.accountId || req.remoteAddress;
const channelName = channelNameFromPath(req);
connectedClients.labels({ type: 'eventsource' }).inc();
// In theory we'll always have a channel name, but channelNameFromPath can return undefined:
if (typeof channelName === 'string') {
connectedChannels.labels({ type: 'eventsource', channel: channelName }).inc();
}
res.setHeader('Content-Type', 'text/event-stream');
res.setHeader('Cache-Control', 'no-store');
res.setHeader('Transfer-Encoding', 'chunked');
res.write(':)\n');
const heartbeat = setInterval(() => res.write(':thump\n'), 15000);
req.on('close', () => {
log.verbose(req.requestId, `Ending stream for ${accountId}`);
// We decrement these counters here instead of in streamHttpEnd as in that
// method we don't have knowledge of the channel names
connectedClients.labels({ type: 'eventsource' }).dec();
// In theory we'll always have a channel name, but channelNameFromPath can return undefined:
if (typeof channelName === 'string') {
connectedChannels.labels({ type: 'eventsource', channel: channelName }).dec();
}
clearInterval(heartbeat);
});
return (event, payload) => {
res.write(`event: ${event}\n`);
res.write(`data: ${payload}\n\n`);
};
};
/**
* @param {any} req
* @param {function(): void} [closeHandler]
* @returns {function(string[], SubscriptionListener): void}
*/
const streamHttpEnd = (req, closeHandler = undefined) => (ids, listener) => {
req.on('close', () => {
ids.forEach(id => {
unsubscribe(id, listener);
});
if (closeHandler) {
closeHandler();
}
});
};
/**
* @param {any} req
* @param {any} ws
* @param {string[]} streamName
* @returns {function(string, string): void}
*/
const streamToWs = (req, ws, streamName) => (event, payload) => {
if (ws.readyState !== ws.OPEN) {
log.error(req.requestId, 'Tried writing to closed socket');
return;
}
ws.send(JSON.stringify({ stream: streamName, event, payload }), (err) => {
if (err) {
log.error(req.requestId, `Failed to send to websocket: ${err}`);
}
});
};
/**
* @param {any} res
*/
const httpNotFound = res => {
res.writeHead(404, { 'Content-Type': 'application/json' });
res.end(JSON.stringify({ error: 'Not found' }));
};
const api = express.Router();
app.use(api);
api.use(setRequestId);
api.use(setRemoteAddress);
api.use(allowCrossDomain);
api.use(authenticationMiddleware);
api.use(errorMiddleware);
api.get('/api/v1/streaming/*', (req, res) => {
channelNameToIds(req, channelNameFromPath(req), req.query).then(({ channelIds, options }) => {
const onSend = streamToHttp(req, res);
const onEnd = streamHttpEnd(req, subscriptionHeartbeat(channelIds));
streamFrom(channelIds, req, onSend, onEnd, 'eventsource', options.needsFiltering);
}).catch(err => {
log.verbose(req.requestId, 'Subscription error:', err.toString());
httpNotFound(res);
});
});
const wss = new WebSocket.Server({ server, verifyClient: wsVerifyClient });
/**
* @typedef StreamParams
* @property {string} [tag]
* @property {string} [list]
* @property {string} [only_media]
*/
/**
* @param {any} req
* @returns {string[]}
*/
const channelsForUserStream = req => {
const arr = [`timeline:${req.accountId}`];
if (isInScope(req, ['crypto']) && req.deviceId) {
arr.push(`timeline:${req.accountId}:${req.deviceId}`);
}
if (isInScope(req, ['read', 'read:notifications'])) {
arr.push(`timeline:${req.accountId}:notifications`);
}
return arr;
};
/**
* See app/lib/ascii_folder.rb for the canon definitions
* of these constants
*/
const NON_ASCII_CHARS = 'ÀÁÂÃÄÅàáâãäåĀāĂ㥹ÇçĆćĈĉĊċČčÐðĎďĐđÈÉÊËèéêëĒēĔĕĖėĘęĚěĜĝĞğĠġĢģĤĥĦħÌÍÎÏìíîïĨĩĪīĬĭĮįİıĴĵĶķĸĹĺĻļĽľĿŀŁłÑñŃńŅņŇňʼnŊŋÒÓÔÕÖØòóôõöøŌōŎŏŐőŔŕŖŗŘřŚśŜŝŞşŠšſŢţŤťŦŧÙÚÛÜùúûüŨũŪūŬŭŮůŰűŲųŴŵÝýÿŶŷŸŹźŻżŽž';
const EQUIVALENT_ASCII_CHARS = 'AAAAAAaaaaaaAaAaAaCcCcCcCcCcDdDdDdEEEEeeeeEeEeEeEeEeGgGgGgGgHhHhIIIIiiiiIiIiIiIiIiJjKkkLlLlLlLlLlNnNnNnNnnNnOOOOOOooooooOoOoOoRrRrRrSsSsSsSssTtTtTtUUUUuuuuUuUuUuUuUuUuWwYyyYyYZzZzZz';
/**
* @param {string} str
* @returns {string}
*/
const foldToASCII = str => {
const regex = new RegExp(NON_ASCII_CHARS.split('').join('|'), 'g');
return str.replace(regex, match => {
const index = NON_ASCII_CHARS.indexOf(match);
return EQUIVALENT_ASCII_CHARS[index];
});
};
/**
* @param {string} str
* @returns {string}
*/
const normalizeHashtag = str => {
return foldToASCII(str.normalize('NFKC').toLowerCase()).replace(/[^\p{L}\p{N}_\u00b7\u200c]/gu, '');
};
/**
* @param {any} req
* @param {string} name
* @param {StreamParams} params
* @returns {Promise.<{ channelIds: string[], options: { needsFiltering: boolean } }>}
*/
const channelNameToIds = (req, name, params) => new Promise((resolve, reject) => {
switch (name) {
case 'user':
resolve({
channelIds: channelsForUserStream(req),
options: { needsFiltering: false },
});
break;
case 'user:notification':
resolve({
channelIds: [`timeline:${req.accountId}:notifications`],
options: { needsFiltering: false },
});
break;
case 'public':
resolve({
channelIds: ['timeline:public'],
options: { needsFiltering: true },
});
break;
case 'public:local':
resolve({
channelIds: ['timeline:public:local'],
options: { needsFiltering: true },
});
break;
case 'public:remote':
resolve({
channelIds: ['timeline:public:remote'],
options: { needsFiltering: true },
});
break;
case 'public:media':
resolve({
channelIds: ['timeline:public:media'],
options: { needsFiltering: true },
});
break;
case 'public:local:media':
resolve({
channelIds: ['timeline:public:local:media'],
options: { needsFiltering: true },
});
break;
case 'public:remote:media':
resolve({
channelIds: ['timeline:public:remote:media'],
options: { needsFiltering: true },
});
break;
case 'direct':
resolve({
channelIds: [`timeline:direct:${req.accountId}`],
options: { needsFiltering: false },
});
break;
case 'hashtag':
if (!params.tag || params.tag.length === 0) {
reject('No tag for stream provided');
} else {
resolve({
channelIds: [`timeline:hashtag:${normalizeHashtag(params.tag)}`],
options: { needsFiltering: true },
});
}
break;
case 'hashtag:local':
if (!params.tag || params.tag.length === 0) {
reject('No tag for stream provided');
} else {
resolve({
channelIds: [`timeline:hashtag:${normalizeHashtag(params.tag)}:local`],
options: { needsFiltering: true },
});
}
break;
case 'list':
authorizeListAccess(params.list, req).then(() => {
resolve({
channelIds: [`timeline:list:${params.list}`],
options: { needsFiltering: false },
});
}).catch(() => {
reject('Not authorized to stream this list');
});
break;
default:
reject('Unknown stream type');
}
});
/**
* @param {string} channelName
* @param {StreamParams} params
* @returns {string[]}
*/
const streamNameFromChannelName = (channelName, params) => {
if (channelName === 'list') {
return [channelName, params.list];
} else if (['hashtag', 'hashtag:local'].includes(channelName)) {
return [channelName, params.tag];
} else {
return [channelName];
}
};
/**
* @typedef WebSocketSession
* @property {any} socket
* @property {any} request
* @property {Object.<string, { channelName: string, listener: SubscriptionListener, stopHeartbeat: function(): void }>} subscriptions
*/
/**
* @param {WebSocketSession} session
* @param {string} channelName
* @param {StreamParams} params
* @returns {void}
*/
const subscribeWebsocketToChannel = ({ socket, request, subscriptions }, channelName, params) => {
checkScopes(request, channelName).then(() => channelNameToIds(request, channelName, params)).then(({
channelIds,
options,
}) => {
if (subscriptions[channelIds.join(';')]) {
return;
}
const onSend = streamToWs(request, socket, streamNameFromChannelName(channelName, params));
const stopHeartbeat = subscriptionHeartbeat(channelIds);
const listener = streamFrom(channelIds, request, onSend, undefined, 'websocket', options.needsFiltering);
connectedChannels.labels({ type: 'websocket', channel: channelName }).inc();
subscriptions[channelIds.join(';')] = {
channelName,
listener,
stopHeartbeat,
};
}).catch(err => {
log.verbose(request.requestId, 'Subscription error:', err.toString());
socket.send(JSON.stringify({ error: err.toString() }));
});
}
const removeSubscription = (subscriptions, channelIds, request) => {
log.verbose(request.requestId, `Ending stream from ${channelIds.join(', ')} for ${request.accountId}`);
const subscription = subscriptions[channelIds.join(';')];
if (!subscription) {
return;
}
channelIds.forEach(channelId => {
unsubscribe(`${redisPrefix}${channelId}`, subscription.listener);
});
connectedChannels.labels({ type: 'websocket', channel: subscription.channelName }).dec();
subscription.stopHeartbeat();
delete subscriptions[channelIds.join(';')];
}
/**
* @param {WebSocketSession} session
* @param {string} channelName
* @param {StreamParams} params
* @returns {void}
*/
const unsubscribeWebsocketFromChannel = ({ socket, request, subscriptions }, channelName, params) => {
channelNameToIds(request, channelName, params).then(({ channelIds }) => {
removeSubscription(subscriptions, channelIds, request);
}).catch(err => {
log.verbose(request.requestId, 'Unsubscribe error:', err);
// If we have a socket that is alive and open still, send the error back to the client:
// FIXME: In other parts of the code ws === socket
if (socket.isAlive && socket.readyState === socket.OPEN) {
socket.send(JSON.stringify({ error: "Error unsubscribing from channel" }));
}
});
}
/**
* @param {WebSocketSession} session
*/
const subscribeWebsocketToSystemChannel = ({ socket, request, subscriptions }) => {
const accessTokenChannelId = `timeline:access_token:${request.accessTokenId}`;
const systemChannelId = `timeline:system:${request.accountId}`;
const listener = createSystemMessageListener(request, {
onKill() {
socket.close();
},
});
subscribe(`${redisPrefix}${accessTokenChannelId}`, listener);
subscribe(`${redisPrefix}${systemChannelId}`, listener);
subscriptions[accessTokenChannelId] = {
channelName: 'system',
listener,
stopHeartbeat: () => {
},
};
subscriptions[systemChannelId] = {
channelName: 'system',
listener,
stopHeartbeat: () => {
},
};
connectedChannels.labels({ type: 'websocket', channel: 'system' }).inc(2);
};
/**
* @param {string|string[]} arrayOrString
* @returns {string}
*/
const firstParam = arrayOrString => {
if (Array.isArray(arrayOrString)) {
return arrayOrString[0];
} else {
return arrayOrString;
}
};
wss.on('connection', (ws, req) => {
// Note: url.parse could throw, which would terminate the connection, so we
// increment the connected clients metric straight away when we establish
// the connection, without waiting:
connectedClients.labels({ type: 'websocket' }).inc();
// Setup request properties:
req.requestId = uuid.v4();
req.remoteAddress = ws._socket.remoteAddress;
// Setup connection keep-alive state:
ws.isAlive = true;
ws.on('pong', () => {
ws.isAlive = true;
});
/**
* @type {WebSocketSession}
*/
const session = {
socket: ws,
request: req,
subscriptions: {},
};
ws.on('close', function onWebsocketClose() {
const subscriptions = Object.keys(session.subscriptions);
subscriptions.forEach(channelIds => {
removeSubscription(session.subscriptions, channelIds.split(';'), req)
});
// Decrement the metrics for connected clients:
connectedClients.labels({ type: 'websocket' }).dec();
// ensure garbage collection:
session.socket = null;
session.request = null;
session.subscriptions = {};
});
// Note: immediately after the `error` event is emitted, the `close` event
// is emitted. As such, all we need to do is log the error here.
ws.on('error', (err) => {
log.error('websocket', err.toString());
});
ws.on('message', (data, isBinary) => {
if (isBinary) {
log.warn('websocket', 'Received binary data, closing connection');
ws.close(1003, 'The mastodon streaming server does not support binary messages');
return;
}
const message = data.toString('utf8');
const json = parseJSON(message, session.request);
if (!json) return;
const { type, stream, ...params } = json;
if (type === 'subscribe') {
subscribeWebsocketToChannel(session, firstParam(stream), params);
} else if (type === 'unsubscribe') {
unsubscribeWebsocketFromChannel(session, firstParam(stream), params);
} else {
// Unknown action type
}
});
subscribeWebsocketToSystemChannel(session);
// Parse the URL for the connection arguments (if supplied), url.parse can throw:
const location = req.url && url.parse(req.url, true);
if (location && location.query.stream) {
subscribeWebsocketToChannel(session, firstParam(location.query.stream), location.query);
}
});
setInterval(() => {
wss.clients.forEach(ws => {
if (ws.isAlive === false) {
ws.terminate();
return;
}
ws.isAlive = false;
ws.ping('', false);
});
}, 30000);
attachServerWithConfig(server, address => {
log.warn(`Streaming API now listening on ${address}`);
});
const onExit = () => {
server.close();
process.exit(0);
};
const onError = (err) => {
log.error(err);
server.close();
process.exit(0);
};
process.on('SIGINT', onExit);
process.on('SIGTERM', onExit);
process.on('exit', onExit);
process.on('uncaughtException', onError);
};
/**
* @param {any} server
* @param {function(string): void} [onSuccess]
*/
const attachServerWithConfig = (server, onSuccess) => {
if (process.env.SOCKET || process.env.PORT && isNaN(+process.env.PORT)) {
server.listen(process.env.SOCKET || process.env.PORT, () => {
if (onSuccess) {
fs.chmodSync(server.address(), 0o666);
onSuccess(server.address());
}
});
} else {
server.listen(+process.env.PORT || 4000, process.env.BIND || '127.0.0.1', () => {
if (onSuccess) {
onSuccess(`${server.address().address}:${server.address().port}`);
}
});
}
};
startServer();