Allow local mode to be controlled via config.json

Change-type: minor
Signed-off-by: Cameron Diver <cameron@balena.io>

src/migrations/M00001.js

@@ -0,0 +1,57 @@
+const fs = require('fs');
+const configJsonPath = process.env.CONFIG_MOUNT_POINT;
+
+const { checkTruthy } = require('../lib/validation');
+
+exports.up = function (knex, Promise) {
+	return knex('config').where({ key: 'localMode' }).select('value')
+		.then((results) => {
+			if (results.length === 0) {
+				// We don't need to do anything
+				return;
+			}
+
+			let value = checkTruthy(results[0].value);
+			value = value != null ? value : false;
+
+			return new Promise((resolve) => {
+				if (!configJsonPath) {
+					console.log('Unable to locate config.json! Things may fail unexpectedly!');
+					resolve();
+					return;
+				}
+				fs.readFile(configJsonPath, (err, data) => {
+					if (err) {
+						console.log('Failed to read config.json! Things may fail unexpectedly!');
+						resolve();
+						return;
+					}
+					try {
+						const parsed = JSON.parse(data.toString());
+						// Assign the local mode value
+						parsed.localMode = value;
+
+						fs.writeFile(configJsonPath, JSON.stringify(parsed), (err) => {
+							if (err) {
+								console.log('Failed to write config.json! Things may fail unexpectedly!');
+								return;
+							}
+							resolve();
+						});
+
+					} catch (e) {
+						console.log('Failed to parse config.json! Things may fail unexpectedly!');
+						resolve();
+					}
+				});
+			})
+				.then(() => {
+					return knex('config').where('key', 'localMode').del();
+				});
+		});
+};
+
+exports.down = function (knex, Promise) {
+	return Promise.reject(new Error('Not Implemented'));
+}
+