start on ip pruning gulp task. works, but uses static 7 days atm.

gulpfile.js

@@ -16,7 +16,7 @@ const gulp = require('gulp')
 	, pug = require('pug')
 	, gulppug = require('gulp-pug')
 	, { migrateVersion } = require(__dirname+'/package.json')
-	, { randomBytes } = require('crypto')
+	, { createHash, randomBytes } = require('crypto')
 	, paths = {
 		styles: {
 			src: 'gulp/res/css/',
@@ -58,6 +58,59 @@ async function password() {
 
 }
 
+async function ips() {
+	/*
+	prune IPs from old posts (actually, rehash them with a temporary random salt to maintain
+	post history and prevent *-by-ip action unintentionally deleting many posts)
+	NOTE: ips may still remain in the following collections:
+	- bans, because bans need the IP to function
+	- modlog actioner ips, modlogs are already auto-pruned
+	- ratelimits, these only last 1 minute
+	- stats, these last max of 24 hours
+	*/
+	const Mongo = require(__dirname+'/db/db.js')
+	await Mongo.connect();
+	const Redis = require(__dirname+'/redis.js')
+	const { Posts } = require(__dirname+'/db/');
+	const beforeDate = new Date();
+	beforeDate.setDate(beforeDate.getDate() - 7); //7 days in the past, static number for now until i implement yargs or similar
+	const beforeDateMongoId = Mongo.ObjectId.createFromTime(Math.floor(beforeDate.getTime()/1000));
+	const tempIpHashSecret = randomBytes(20).toString('base64');
+	const bulkWrites = [];
+	await Posts.db.find({
+		_id: {
+			$lte: beforeDateMongoId,
+		},
+		'ip.pruned': {
+			$ne: true
+		}
+	}).forEach(post => {
+		const randomIP = createHash('sha256').update(tempIpHashSecret + post.ip.single).digest('base64');
+		bulkWrites.push({
+			updateOne: {
+				filter: {
+					_id: post._id,
+				},
+				update: {
+					$set: {
+						'ip.pruned': true,
+						'ip.raw': randomIP,
+						'ip.single': randomIP,
+						'ip.qrange': randomIP,
+						'ip.hrange': randomIP,
+					}
+				}
+			}
+		});
+	});
+	console.log(`Randomising ip on ${bulkWrites.length} posts`);
+	if (bulkWrites.length.length > 0) {
+		await Posts.db.bulkWrite(bulkWrites);
+	}
+	Redis.redisClient.quit();
+	return Mongo.client.close();
+}
+
 async function wipe() {
 
 	const Mongo = require(__dirname+'/db/db.js')
@@ -397,5 +450,6 @@ module.exports = {
 	cache,
 	migrate,
 	password,
+	ips,
 	default: build,
 };