A very tiny package (zero dependencies) that allows you to read json configuration file and environment variables
When parsing, following steps proceed in this order:
- Read default values
- Read json config file. All existing values overwrite its default values
- Read all environment variables with specified prefix. All existing values overwrite its config values and default values
$ npm install light-confSome arguments are optional, but you can not skip them, you should use undefined instead of correct values
ConfigManager arguments
- configDefaultKeyValues - object with default config key values, required
- configFilePath - string with absolute path to json config file, required
- environment - object with environment variable key values (typically it will be process.env), required
- envPrefix - string with environment variable prefix to read (variables without that prefix will be ignored), required
- backwardCompatibilityFunction - function that pre-process json config content, optional
- keyTypeMapping - object with type mapping for key values (if you want to explicit type conversion from string for environment variables), optional
const ConfigManager = require("light-conf");
const configDefaultKeyValues = {
"key2": 10,
"key3": 3.14,
};
// config.json content
//const configFileContent = {
// "key1": false,
// "key2": 20,
// "key6": ["value0"],
//}
process.env.EP_KEY1 = "true";
process.env.EP_KEY4 = "120000";
process.env.EP_KEY5 = "year";
process.env.EP_KEY6 = "value1;value2";
function backwardCompatibilityFunction(configFileContent) {
// do staff with config for older config files
return configFileContent;
}
const keyTypeMapping = {
"key1": "boolean",
"key2": "integer",
"key3": "double",
"key4": "try_integer",
"key5": "try_integer",
"key6": "array",
};
const config = new ConfigManager(
configDefaultKeyValues,
path.join(__dirname, "config.json"),
process.env,
"EP_",
backwardCompatibilityFunction,
keyTypeMapping,
);
console.log(
config.get("key1")
);
// should print true (env var value overwritten all other)
console.log(
config.get("key2")
);
// should print 20 (cfg value overwritten default value)
console.log(
config.get("key3")
);
// should print 3.14 (default value not overwritten by anything)
console.log(
config.get("key4")
);
// should print 120000 (integer type)
console.log(
config.get("key5")
);
// should print year (string type)
console.log(
config.get("key6")
);
// should print ["value1", "value2"] (stringified array type)
console.log(
config.get()
);
// should print all config values