cloudron-box/src/backups.js

'use strict';

exports = module.exports = {
    startBackupTask,

    startCleanupTask,
    cleanupCacheFilesSync,

    removePrivateFields,

    generateEncryptionKeysSync,

    getSnapshotInfo,
    setSnapshotInfo,

    validatePolicy,
    testStorage,
    validateFormat,

    getPolicy,
    setPolicy,

    getTarget,

    getConfig,
    setConfig,
    setStorage,
    setLimits,

    getRootPath,
    setupManagedStorage,

    remount,
    getMountStatus,
    ensureMounted,

    _addDefaultTarget: addDefaultTarget,

    BACKUP_IDENTIFIER_BOX: 'box',
    BACKUP_IDENTIFIER_MAIL: 'mail',

    BACKUP_TYPE_APP: 'app',
    BACKUP_TYPE_BOX: 'box',
    BACKUP_TYPE_MAIL: 'mail',

    BACKUP_STATE_NORMAL: 'normal', // should rename to created to avoid listing in UI?
    BACKUP_STATE_CREATING: 'creating',
    BACKUP_STATE_ERROR: 'error',
};

const assert = require('assert'),
    backupListing = require('./backuplisting.js'),
    BoxError = require('./boxerror.js'),
    constants = require('./constants.js'),
    cron = require('./cron.js'),
    { CronTime } = require('cron'),
    crypto = require('crypto'),
    database = require('./database.js'),
    debug = require('debug')('box:backups'),
    eventlog = require('./eventlog.js'),
    locks = require('./locks.js'),
    mounts = require('./mounts.js'),
    path = require('path'),
    paths = require('./paths.js'),
    safe = require('safetydance'),
    settings = require('./settings.js'),
    storage = require('./storage.js'),
    tasks = require('./tasks.js'),
    uuid = require('uuid'),
    _ = require('./underscore.js');

const BACKUP_TARGET_FIELDS = [ 'id', 'label', 'configJson', 'limitsJson', 'retentionJson', 'schedule', 'encryptionJson', 'format', 'priority', 'creationTime', 'ts' ].join(',');

function postProcess(result) {
    assert.strictEqual(typeof result, 'object');

    result.config = result.configJson ? safe.JSON.parse(result.configJson) : {};
    delete result.configJson;

    result.limits = result.limitsJson ? safe.JSON.parse(result.limitsJson) : {};
    delete result.limitsJson;

    result.retention = result.retentionJson ? safe.JSON.parse(result.retentionJson) : {};
    delete result.retentionJson;

    result.encryption = result.encryptionJson ? safe.JSON.parse(result.encryptionJson) : null;
    delete result.encryptionJson;

    result.priority = !!result.priority;

    return result;
}

function removePrivateFields(backupConfig) {
    assert.strictEqual(typeof backupConfig, 'object');
    if (backupConfig.encryption) {
        delete backupConfig.encryption;
        backupConfig.password = constants.SECRET_PLACEHOLDER;
    }
    delete backupConfig.rootPath;
    return storage.api(backupConfig.provider).removePrivateFields(backupConfig);
}

// this function is used in migrations - 20200512172301-settings-backup-encryption.js
function generateEncryptionKeysSync(password) {
    assert.strictEqual(typeof password, 'string');

    const aesKeys = crypto.scryptSync(password, Buffer.from('CLOUDRONSCRYPTSALT', 'utf8'), 128);
    return {
        dataKey: aesKeys.subarray(0, 32).toString('hex'),
        dataHmacKey: aesKeys.subarray(32, 64).toString('hex'),
        filenameKey: aesKeys.subarray(64, 96).toString('hex'),
        filenameHmacKey: aesKeys.subarray(96).toString('hex')
    };
}

async function validatePolicy(policy) {
    assert.strictEqual(typeof policy, 'object');

    const job = safe.safeCall(function () { return new CronTime(policy.schedule); });
    if (!job) return new BoxError(BoxError.BAD_FIELD, 'Invalid schedule pattern');

    const retention = policy.retention;
    if (!retention) return new BoxError(BoxError.BAD_FIELD, 'retention is required');
    if (!['keepWithinSecs','keepDaily','keepWeekly','keepMonthly','keepYearly'].find(k => !!retention[k])) return new BoxError(BoxError.BAD_FIELD, 'retention properties missing');
    if ('keepWithinSecs' in retention && typeof retention.keepWithinSecs !== 'number') return new BoxError(BoxError.BAD_FIELD, 'retention.keepWithinSecs must be a number');
    if ('keepDaily' in retention && typeof retention.keepDaily !== 'number') return new BoxError(BoxError.BAD_FIELD, 'retention.keepDaily must be a number');
    if ('keepWeekly' in retention && typeof retention.keepWeekly !== 'number') return new BoxError(BoxError.BAD_FIELD, 'retention.keepWeekly must be a number');
    if ('keepMonthly' in retention && typeof retention.keepMonthly !== 'number') return new BoxError(BoxError.BAD_FIELD, 'retention.keepMonthly must be a number');
    if ('keepYearly' in retention && typeof retention.keepYearly !== 'number') return new BoxError(BoxError.BAD_FIELD, 'retention.keepYearly must be a number');
}

async function startBackupTask(auditSource) {
    const [error] = await safe(locks.acquire(locks.TYPE_FULL_BACKUP_TASK));
    if (error) throw new BoxError(BoxError.BAD_STATE, `Another backup task is in progress: ${error.message}`);

    const backupConfig = await getConfig();

    const memoryLimit = backupConfig.limits?.memoryLimit ? Math.max(backupConfig.limits.memoryLimit/1024/1024, 1024) : 1024;

    const taskId = await tasks.add(tasks.TASK_BACKUP, [ { /* options */ } ]);

    await eventlog.add(eventlog.ACTION_BACKUP_START, auditSource, { taskId });

    // background
    tasks.startTask(taskId, { timeout: 24 * 60 * 60 * 1000 /* 24 hours */, nice: 15, memoryLimit, oomScoreAdjust: -999 })
        .then(async (backupId) => {
            const backup = await backupListing.get(backupId);
            await eventlog.add(eventlog.ACTION_BACKUP_FINISH, auditSource, { taskId, backupId, remotePath: backup.remotePath });
        })
        .catch(async (error) => {
            const timedOut = error.code === tasks.ETIMEOUT;
            await safe(eventlog.add(eventlog.ACTION_BACKUP_FINISH, auditSource, { taskId, errorMessage: error.message, timedOut }));
        })
        .finally(async () => {
            await locks.release(locks.TYPE_FULL_BACKUP_TASK);
            await locks.releaseByTaskId(taskId);
        });

    return taskId;
}

// this function is used in migrations - 20200512172301-settings-backup-encryption.js
function cleanupCacheFilesSync() {
    const files = safe.fs.readdirSync(path.join(paths.BACKUP_INFO_DIR));
    if (!files) return;

    files
        .filter(function (f) { return f.endsWith('.sync.cache'); })
        .forEach(function (f) {
            safe.fs.unlinkSync(path.join(paths.BACKUP_INFO_DIR, f));
        });
}

function getSnapshotInfo(id) {
    assert.strictEqual(typeof id, 'string');

    const contents = safe.fs.readFileSync(paths.SNAPSHOT_INFO_FILE, 'utf8');
    const info = safe.JSON.parse(contents);
    if (!info) return { };
    return info[id] || { };
}

// keeps track of contents of the snapshot directory. this provides a way to clean up backups of uninstalled apps
async function setSnapshotInfo(id, info) {
    assert.strictEqual(typeof id, 'string');
    assert.strictEqual(typeof info, 'object');

    const contents = safe.fs.readFileSync(paths.SNAPSHOT_INFO_FILE, 'utf8');
    const data = safe.JSON.parse(contents) || { };
    if (info) data[id] = info; else delete data[id];
    if (!safe.fs.writeFileSync(paths.SNAPSHOT_INFO_FILE, JSON.stringify(data, null, 4), 'utf8')) {
        throw new BoxError(BoxError.FS_ERROR, safe.error.message);
    }
}

async function startCleanupTask(auditSource) {
    assert.strictEqual(typeof auditSource, 'object');

    const taskId = await tasks.add(tasks.TASK_CLEAN_BACKUPS, []);

    // background
    tasks.startTask(taskId, {})
        .then(async (result) => { // { removedBoxBackupPaths, removedAppBackupPaths, removedMailBackupPaths, missingBackupPaths }
            await eventlog.add(eventlog.ACTION_BACKUP_CLEANUP_FINISH, auditSource, { taskId, errorMessage: null, ...result });
        })
        .catch(async (error) => {
            await eventlog.add(eventlog.ACTION_BACKUP_CLEANUP_FINISH, auditSource, { taskId, errorMessage: error.message });

        });

    return taskId;
}

async function testStorage(storageConfig) {
    assert.strictEqual(typeof storageConfig, 'object');

    const func = storage.api(storageConfig.provider);
    if (!func) return new BoxError(BoxError.BAD_FIELD, 'unknown storage provider');

    await storage.api(storageConfig.provider).testConfig(storageConfig);
}

function validateEncryptionPassword(password) {
    assert.strictEqual(typeof password, 'string');

    if (password.length < 8) return new BoxError(BoxError.BAD_FIELD, 'password must be atleast 8 characters');
}

function managedBackupMountObject(backupConfig) {
    assert(mounts.isManagedProvider(backupConfig.provider));

    return {
        name: 'backup',
        hostPath: paths.MANAGED_BACKUP_MOUNT_DIR,
        mountType: backupConfig.provider,
        mountOptions: backupConfig.mountOptions
    };
}

async function remount() {
    const backupConfig = await getConfig();

    if (mounts.isManagedProvider(backupConfig.provider)) {
        await mounts.remount(managedBackupMountObject(backupConfig));
    }
}

async function getMountStatus() {
    const backupConfig = await getConfig();

    let hostPath;
    if (mounts.isManagedProvider(backupConfig.provider)) {
        hostPath = paths.MANAGED_BACKUP_MOUNT_DIR;
    } else if (backupConfig.provider === 'mountpoint') {
        hostPath = backupConfig.mountPoint;
    } else if (backupConfig.provider === 'filesystem') {
        hostPath = backupConfig.backupFolder;
    } else {
        return { state: 'active' };
    }

    return await mounts.getStatus(backupConfig.provider, hostPath); // { state, message }
}

async function ensureMounted() {
    const status = await getMountStatus();
    if (status.state === 'active') return status;

    await remount();
    return await getMountStatus();
}

async function getPolicy() {
    const results = await database.query(`SELECT ${BACKUP_TARGET_FIELDS} FROM backupTargets WHERE priority=?`, [ true ]);
    const result = postProcess(results[0]);
    return { retention: result.retention, schedule: result.schedule };
}

async function setPolicy(policy) {
    assert.strictEqual(typeof policy, 'object');

    const error = await validatePolicy(policy);
    if (error) throw error;

    await updateTarget(policy);

    await cron.handleBackupPolicyChanged(policy);
}

function getRootPath(storageConfig, mountPath) {
    assert.strictEqual(typeof storageConfig, 'object');
    assert.strictEqual(typeof mountPath, 'string');

    if (mounts.isManagedProvider(storageConfig.provider)) {
        return path.join(mountPath, storageConfig.prefix);
    } else if (storageConfig.provider === 'mountpoint') {
        return path.join(storageConfig.mountPoint, storageConfig.prefix);
    } else if (storageConfig.provider === 'filesystem') {
        return storageConfig.backupFolder;
    } else {
        return storageConfig.prefix;
    }
}

async function updateTarget(data) {
    assert(data && typeof data === 'object');

    const args = [];
    const fields = [];
    for (const k in data) {
        if (k === 'label' || k === 'schedule' || k === 'format' || k === 'priority') {
            fields.push(k + ' = ?');
            args.push(data[k]);
        } else if (k === 'config' || k === 'limits' || k === 'retention' || k === 'encryption') {
            fields.push(`${k}JSON = ?`);
            args.push(JSON.stringify(data[k]));
        }
    }
    args.push(true); // primary flag

    const [updateError, result] = await safe(database.query('UPDATE backupTargets SET ' + fields.join(', ') + ' WHERE priority = ?', args));
    if (updateError) throw updateError;
    if (result.affectedRows !== 1) throw new BoxError(BoxError.NOT_FOUND, 'Target not found');
}

async function addDefaultTarget() {
    const label = '', priority = true;
    const limits = null, encryption = null;
    const retention = { keepWithinSecs: 2 * 24 * 60 * 60 };
    const schedule = '00 00 23 * * *';;
    const config = { provider: 'filesystem', backupFolder: paths.DEFAULT_BACKUP_DIR };
    const format = 'tgz';

    const id = `bc-${uuid.v4()}`;
    await database.query('INSERT INTO backupTargets (id, label, configJson, limitsJson, retentionJson, schedule, encryptionJson, format, priority) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)',
        [ id, label, JSON.stringify(config), JSON.stringify(limits), JSON.stringify(retention), schedule, JSON.stringify(encryption), format, priority ]);
    return id;
}

async function getTarget(id) {
    const results = await database.query(`SELECT ${BACKUP_TARGET_FIELDS} FROM backupTargets WHERE id=?`, [ id ]);
    if (results.length === 0) return null;
    return postProcess(results[0]);
}

async function getConfig() {
    const results = await database.query(`SELECT ${BACKUP_TARGET_FIELDS} FROM backupTargets WHERE priority=?`, [ true ]);
    const result = postProcess(results[0]);

    const config = result.config;
    config.format = result.format;
    config.encryption = result.encryption;
    config.rootPath = getRootPath(config, paths.MANAGED_BACKUP_MOUNT_DIR); // note: rootPath will be dynamic for managed mount providers during app import

    return config;
}

async function setConfig(backupConfig) {
    assert.strictEqual(typeof backupConfig, 'object');

    await updateTarget({
        config: _.omit(backupConfig, ['limits', 'format', 'encryption']),
        format: backupConfig.format,
        encryption: backupConfig.encryption || null,
        limits: backupConfig.limits || null
    });
}

async function setLimits(limits) {
    assert.strictEqual(typeof limits, 'object');

    await settings.setJson(settings.BACKUP_LIMITS_KEY, limits);
}

function validateFormat(format) {
    assert.strictEqual(typeof format, 'string');

    if (format === 'tgz' || format == 'rsync') return null;

    return new BoxError(BoxError.BAD_FIELD, 'Invalid backup format');
}

async function setupManagedStorage(storageConfig, hostPath) {
    assert.strictEqual(typeof storageConfig, 'object');
    assert.strictEqual(typeof hostPath, 'string');

    if (!mounts.isManagedProvider(storageConfig.provider)) return null;

    if (!storageConfig.mountOptions || typeof storageConfig.mountOptions !== 'object') throw new BoxError(BoxError.BAD_FIELD, 'mountOptions must be an object');

    const error = mounts.validateMountOptions(storageConfig.provider, storageConfig.mountOptions);
    if (error) throw error;

    debug(`setupManagedStorage: setting up mount at ${hostPath} with ${storageConfig.provider}`);

    const newMount = {
        name: path.basename(hostPath),
        hostPath,
        mountType: storageConfig.provider,
        mountOptions: storageConfig.mountOptions
    };

    await mounts.tryAddMount(newMount, { timeout: 10 }); // 10 seconds

    return newMount;
}

async function setStorage(storageConfig) {
    assert.strictEqual(typeof storageConfig, 'object');

    if (constants.DEMO) throw new BoxError(BoxError.BAD_STATE, 'Not allowed in demo mode');

    const oldConfig = await getConfig();

    if (storageConfig.provider === oldConfig.provider) storage.api(storageConfig.provider).injectPrivateFields(storageConfig, oldConfig);

    const formatError = validateFormat(storageConfig.format);
    if (formatError) throw formatError;

    storageConfig.encryption = null;
    if ('password' in storageConfig) { // user set password
        if (storageConfig.password === constants.SECRET_PLACEHOLDER) {
            storageConfig.encryption = oldConfig.encryption || null;
        } else {
            const encryptionPasswordError = validateEncryptionPassword(storageConfig.password);
            if (encryptionPasswordError) throw encryptionPasswordError;

            storageConfig.encryption = generateEncryptionKeysSync(storageConfig.password);
        }
        delete storageConfig.password;
    }

    debug('setStorage: validating new storage configuration');
    const testMountObject = await setupManagedStorage(storageConfig, '/mnt/backup-storage-validation'); // this validates mountOptions
    const testStorageError = await testStorage(Object.assign({ mountPath: '/mnt/backup-storage-validation' }, storageConfig)); // this validates provider and it's api options. requires mountPath
    if (testMountObject) await mounts.removeMount(testMountObject);
    if (testStorageError) throw testStorageError;

    debug('setStorage: removing old storage configuration');
    if (mounts.isManagedProvider(oldConfig.provider)) await safe(mounts.removeMount(managedBackupMountObject(oldConfig)));

    debug('setStorage: setting up new storage configuration');
    await setupManagedStorage(storageConfig, paths.MANAGED_BACKUP_MOUNT_DIR);

    debug('setStorage: clearing backup cache');
    cleanupCacheFilesSync();

    await setConfig(storageConfig);
}