fix: add --version flag (#620)

README.md

@@ -58,6 +58,8 @@ Run the service from any directory on your machine:
 substrate-api-sidecar
 ```
 
+To check your version you may append the `--version` flag to `substrate-api-sidecar`.
+
 ### Local installation
 
 Install the service locally:

src/logging/Log.ts

@@ -1,24 +1,26 @@
 import { createLogger, Logger } from 'winston';
+import { ConsoleTransportInstance } from 'winston/lib/winston/transports';
 
 import { consoleTransport } from './transports';
 
-// Note: there is a `fileTransport` that gets added in main.
-const transports = [consoleTransport()];
-
 /**
  * Access a singleton winston.Logger that will be intialized on first use.
  */
 export class Log {
+	private static _transports: ConsoleTransportInstance[] | undefined;
 	private static _logger: Logger | undefined;
 	private static create(): Logger {
 		if (this._logger) {
 			return this._logger;
 		}
 
+		// Note: there is a `fileTransport` that gets added in main.
+		this._transports = [consoleTransport()];
+
 		this._logger = createLogger({
-			transports,
+			transports: this._transports,
 			exitOnError: false,
-			exceptionHandlers: transports,
+			exceptionHandlers: this._transports,
 		});
 
 		return this._logger;

src/logging/transports/consoleTransport.ts

@@ -10,14 +10,13 @@ import {
 	timeStamp,
 } from '../transformers';
 
-const {
-	config: { LOG },
-} = SidecarConfig;
-
 /**
  * Console transport for winston logger.
  */
 export function consoleTransport(): transports.ConsoleTransportInstance {
+	const {
+		config: { LOG },
+	} = SidecarConfig;
 	/**
 	 * A simple printing format for how `TransformableInfo` shows up.
 	 */

src/main.ts

@@ -28,12 +28,12 @@ import { getControllersForSpec } from './chains-config';
 import { consoleOverride } from './logging/consoleOverride';
 import { Log } from './logging/Log';
 import * as middleware from './middleware';
+import { parseArgs } from './parseArgs';
 import { SidecarConfig } from './SidecarConfig';
 
-const { logger } = Log;
-const { config } = SidecarConfig;
-
 async function main() {
+	const { config } = SidecarConfig;
+	const { logger } = Log;
 	// Overide console.{log, error, warn, etc}
 	consoleOverride(logger);
 
@@ -88,12 +88,6 @@ async function main() {
 	app.listen();
 }
 
-process.on('SIGINT', function () {
-	console.log('Caught interrupt signal, exiting...');
-	process.exit(0);
-});
-main().catch(console.log);
-
 /**
  * Prompt the user with some basic info about the node and the network they have
  * connected Sidecar to.
@@ -103,6 +97,8 @@ main().catch(console.log);
  * @param implName implementation name of the node Sidecar is connected to
  */
 function startUpPrompt(wsUrl: string, chainName: string, implName: string) {
+	const { logger } = Log;
+	const { config } = SidecarConfig;
 	/**
 	 * Best effort list of known public nodes that do not encourage high traffic
 	 * sidecar installations connecting to them for non - testing / development purposes.
@@ -150,3 +146,17 @@ function startUpPrompt(wsUrl: string, chainName: string, implName: string) {
 		);
 	}
 }
+
+process.on('SIGINT', function () {
+	console.log('Caught interrupt signal, exiting...');
+	process.exit(0);
+});
+
+const args = parseArgs();
+
+if (args.version) {
+	console.log(`@substrate/api-sidecar v${packageJSON.version}`);
+	process.exit(0);
+} else {
+	main().catch(console.log);
+}

src/parseArgs.ts

@@ -0,0 +1,9 @@
+import { ArgumentParser, Namespace } from 'argparse';
+
+export const parseArgs = (): Namespace => {
+	const parser = new ArgumentParser();
+
+	parser.add_argument('-v', '--version', { action: 'store_true' });
+
+	return parser.parse_args() as Namespace;
+};