23bcc0bb06
* Use [node-]redis as a direct dependency * Extract Redis client creation to its own module * Attach extensive logging in the Redis client creation module * Allow the rate limiter to pass requests when Redis is disconnected * Update rate-limit-redis * Default error input to empty object for formatRedisError method * Provide a name for the rate limiter's Redis client Co-authored-by: Kevin Heis <heiskr@users.noreply.github.com> Co-authored-by: Rachael Sewell <rachmari@github.com>
80 lines
2.5 KiB
JavaScript
80 lines
2.5 KiB
JavaScript
const Redis = require('redis')
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const { REDIS_MIN_DB, REDIS_MAX_DB } = process.env
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// By default, every Redis instance supports database numbers 0 - 15
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const redisMinDb = REDIS_MIN_DB || 0
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const redisMaxDb = REDIS_MAX_DB || 15
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function formatRedisError (error = {}) {
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const { code } = error
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const preamble = error.constructor.name + (code ? ` with code "${code}"` : '')
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return preamble + error.toString()
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}
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module.exports = function createClient (options = {}) {
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const { db, name, url } = options
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// If no Redis URL is provided, bail out
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// NOTE: Could support other options like `host`, `port`, and `path` but
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// choosing not to for the time being!
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if (!url) return null
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// Verify database number is within range
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if (db != null) {
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if (!Number.isInteger(db) || db < redisMinDb || db > redisMaxDb) {
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throw new TypeError(
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`Redis database number must be an integer between ${redisMinDb} and ${redisMaxDb} but was: ${JSON.stringify(db)}`
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)
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}
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}
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// Create the client
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const client = Redis.createClient(url, {
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// Only add this configuration for TLS-enabled Redis URL values.
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// Otherwise, it breaks for local Redis instances without TLS enabled.
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...url.startsWith('rediss://') && {
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tls: {
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// Required for production Heroku Redis
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rejectUnauthorized: false
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}
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},
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// Expand whatever other options and overrides were provided
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...options
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})
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// If a `name` was provided, use it in the prefix for logging event messages
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const logPrefix = '[redis' + (name ? ` (${name})` : '') + '] '
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// Add event listeners for basic logging
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client.on('connect', () => { console.log(logPrefix, 'Connection opened') })
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client.on('ready', () => { console.log(logPrefix, 'Ready to receive commands') })
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client.on(
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'reconnecting',
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({
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attempt,
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delay,
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// The rest are unofficial properties but currently supported
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error,
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total_retry_time: totalRetryTime,
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times_connected: timesConnected
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}) => {
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console.log(
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logPrefix,
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'Reconnecting,',
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`attempt ${attempt}`,
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`with ${delay} delay`,
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`due to ${formatRedisError(error)}.`,
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`Elapsed time: ${totalRetryTime}.`,
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`Successful connections: ${timesConnected}.`
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)
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}
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)
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client.on('end', () => { console.log(logPrefix, 'Connection closed') })
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client.on('warning', (msg) => { console.warn(logPrefix, 'Warning:', msg) })
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client.on('error', (error) => { console.error(logPrefix, formatRedisError(error)) })
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return client
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}
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