added docker support

reworked backend to allow for containerization. config items can now be overwritten by environment vars

fixed bug during building

updated youtube-dl version in backend

backend/config.js

@@ -0,0 +1,112 @@
+const fs = require('fs');
+
+let CONFIG_ITEMS = require('./consts.js')['CONFIG_ITEMS'];
+
+let configPath = 'config/default.json';
+
+// https://stackoverflow.com/questions/6491463/accessing-nested-javascript-objects-with-string-key
+Object.byString = function(o, s) {
+    s = s.replace(/\[(\w+)\]/g, '.$1'); // convert indexes to properties
+    s = s.replace(/^\./, '');           // strip a leading dot
+    var a = s.split('.');
+    for (var i = 0, n = a.length; i < n; ++i) {
+        var k = a[i];
+        if (k in o) {
+            o = o[k];
+        } else {
+            return;
+        }
+    }
+    return o;
+}
+
+function getParentPath(path) {
+    let elements = path.split('.');
+    elements.splice(elements.length - 1, 1);
+    return elements.join('.');
+}
+
+function getElementNameInConfig(path) {
+    let elements = path.split('.');
+    return elements[elements.length - 1];
+}
+
+/*
+* Gets config file and returns as a json
+*/
+function getConfigFile() {
+    let raw_data = fs.readFileSync(configPath);
+    try {
+        let parsed_data = JSON.parse(raw_data);
+        return parsed_data;
+    } catch(e) {
+        console.log('ERROR: Failed to get config file');
+        return null;
+    }
+}
+
+function setConfigFile(config) {
+    try {
+        fs.writeFileSync(configPath, JSON.stringify(config, null, 2));
+        return true;
+    } catch(e) {
+        return false;
+    }
+}
+
+function getConfigItem(key) {
+    let config_json = getConfigFile();
+    if (!CONFIG_ITEMS[key]) console.log('cannot find config with key ' + key);
+    let path = CONFIG_ITEMS[key]['path'];
+    return Object.byString(config_json, path);
+};
+
+function setConfigItem(key, value) {
+    let success = false;
+    let config_json = getConfigFile();
+    let path = CONFIG_ITEMS[key]['path'];
+    let parent_path = getParentPath(path);
+    let element_name = getElementNameInConfig(path);
+    
+    let parent_object = Object.byString(config_json, parent_path);
+    if (value === 'false' || value === 'true') {
+        parent_object[element_name] = (value === 'true');
+    } else {
+        parent_object[element_name] = value;
+    }
+
+    success = setConfigFile(config_json);
+
+    return success;
+};
+
+function setConfigItems(items) {
+    let success = false;
+    let config_json = getConfigFile();
+    for (let i = 0; i < items.length; i++) {
+        let key = items[i].key;
+        let value = items[i].value;
+
+        // if boolean strings, set to booleans again
+        if (value === 'false' || value === 'true') {
+            value = (value === 'true');
+        }
+
+        let item_path = CONFIG_ITEMS[key]['path'];
+        let item_parent_path = getParentPath(item_path);
+        let item_element_name = getElementNameInConfig(item_path);
+        
+        let item_parent_object = Object.byString(config_json, item_parent_path);
+        item_parent_object[item_element_name] = value;
+    }
+
+    success = setConfigFile(config_json);
+    return success;
+}
+
+module.exports = {
+    getConfigItem: getConfigItem,
+    setConfigItem: setConfigItem,
+    setConfigItems: setConfigItems,
+    CONFIG_ITEMS: CONFIG_ITEMS
+}