Webatrice: improve prebuild steps and add .env configs (#4564)

* create .env file for server configuration

* render client version

* automate env file

* add prestart command

* create server-props.json instead of using .env

* automate master proto file

Co-authored-by: Jeremy Letto <jeremy.letto@datasite.com>

webclient/prebuild.js

@@ -0,0 +1,58 @@
+const fse = require('fs-extra');
+const util = require('util');
+const exec = util.promisify(require('child_process').exec);
+
+const protoFilesDir = './public/pb';
+const serverPropsFile = './src/server-props.json';
+const masterProtoFile = './src/proto-files.json';
+
+const sharedFiles = [
+  ['../common/pb', protoFilesDir],
+  ['../cockatrice/resources/countries', './src/images/countries'],
+];
+
+
+(async () => {
+  // make sure these files finish copying before master file is created
+  await copySharedFiles();
+
+  createMasterProtoFile();
+  createServerProps();
+})();
+
+async function copySharedFiles() {
+  try {
+    return await Promise.all(sharedFiles.map(([src, dest]) => fse.copy(src, dest, { overwrite: true })));
+  } catch (e) {
+    console.error(e);
+    process.exitCode = 1;
+  }
+}
+
+function createMasterProtoFile() {
+  try {
+    fse.readdir(protoFilesDir, (err, files) => {
+      if (err) throw err;
+
+      fse.outputFile(masterProtoFile, JSON.stringify(files.filter(file => /\.proto$/.test(file))));
+    });
+  } catch (e) {
+    console.error(e);
+    process.exitCode = 1;
+  }
+}
+
+async function createServerProps() {
+  try {
+    fse.outputFile(serverPropsFile, JSON.stringify({
+      REACT_APP_VERSION: await getCommitHash(),
+    }));
+  } catch (e) {
+    console.error(e);
+    process.exitCode = 1;
+  }
+}
+
+async function getCommitHash() {
+  return (await exec('git rev-parse HEAD')).stdout.trim();
+}