Add abstraction over environment values

packages/graph-explorer-proxy-server/src/env.ts

@@ -0,0 +1,44 @@
+import dotenv from "dotenv";
+import path from "path";
+import { clientRoot } from "./paths.js";
+import { z } from "zod";
+
+/** Coerces a string to a boolean value in a case insensitive way. */
+const BooleanStringSchema = z
+  .string()
+  .refine(s => s.toLowerCase() === "true" || s.toLowerCase() === "false")
+  .transform(s => s.toLowerCase() === "true");
+
+// Define a required schema for the values we expect along with their defaults
+const EnvironmentValuesSchema = z.object({
+  HOST: z.string().default("localhost"),
+  PROXY_SERVER_HTTPS_CONNECTION: BooleanStringSchema.default("false"),
+  PROXY_SERVER_HTTPS_PORT: z.coerce.number().default(443),
+  PROXY_SERVER_HTTP_PORT: z.coerce.number().default(80),
+  LOG_LEVEL: z
+    .enum(["fatal", "error", "warn", "info", "debug", "trace", "silent"])
+    .default("debug"),
+  LOG_STYLE: z.enum(["cloudwatch", "default"]).default("default"),
+});
+
+// Load environment variables from .env file.
+dotenv.config({
+  path: [path.join(clientRoot, ".env.local"), path.join(clientRoot, ".env")],
+});
+
+// Parse the environment values from the process
+const parsedEnvironmentValues = EnvironmentValuesSchema.safeParse(process.env);
+
+if (!parsedEnvironmentValues.success) {
+  console.error("Failed to parse environment values");
+  const flattenedErrors = parsedEnvironmentValues.error.flatten();
+  console.error(flattenedErrors.fieldErrors);
+  process.exit(1);
+}
+
+console.log("Parsed environment values:", parsedEnvironmentValues.data);
+
+// Adds all environment values to local object
+export const env = {
+  ...parsedEnvironmentValues.data,
+};

packages/graph-explorer-proxy-server/src/logging.ts

@@ -1,37 +1,16 @@
 import { NextFunction, Request, Response } from "express";
 import { pino } from "pino";
 import { PrettyOptions } from "pino-pretty";
-import { z } from "zod";
+import { env } from "./env.js";
 
 export type LogLevel = pino.LevelWithSilent;
 
-const LogLevelSchema = z.enum([
-  "fatal",
-  "error",
-  "warn",
-  "info",
-  "debug",
-  "trace",
-  "silent",
-]);
-
 export const logger = createLogger();
 
-/** Parses the log level from a given string. If the value is unrecognized or undefined, the default is "info". */
-function toLogLevel(value: string | undefined): LogLevel {
-  const parsed = LogLevelSchema.safeParse(value);
-
-  if (!parsed.success) {
-    return "info";
-  }
-
-  return parsed.data;
-}
-
 /** Create a logger instance with pino. */
 function createLogger() {
   // Check whether we are configured with CloudWatch style
-  const loggingInCloudWatch = process.env.LOG_STYLE === "cloudwatch";
+  const loggingInCloudWatch = env.LOG_STYLE === "cloudwatch";
   const options: PrettyOptions = loggingInCloudWatch
     ? {
         // Avoid colors
@@ -43,7 +22,7 @@ function createLogger() {
         colorize: true,
         translateTime: true,
       };
-  const level = toLogLevel(process.env.LOG_LEVEL);
+  const level = env.LOG_LEVEL;
 
   return pino({
     level,

packages/graph-explorer-proxy-server/src/node-server.ts

@@ -1,7 +1,6 @@
 import express, { NextFunction, Response } from "express";
 import cors from "cors";
 import compression from "compression";
-import dotenv from "dotenv";
 import fetch, { RequestInit } from "node-fetch";
 import https from "https";
 import bodyParser from "body-parser";
@@ -13,14 +12,10 @@ import { IncomingHttpHeaders } from "http";
 import { logger as proxyLogger, requestLoggingMiddleware } from "./logging.js";
 import { clientRoot, proxyServerRoot } from "./paths.js";
 import { errorHandlingMiddleware, handleError } from "./error-handler.js";
+import { env } from "./env.js";
 
 const app = express();
 
-// Load environment variables from .env file.
-dotenv.config({
-  path: [path.join(clientRoot, ".env.local"), path.join(clientRoot, ".env")],
-});
-
 const DEFAULT_SERVICE_TYPE = "neptune-db";
 
 interface DbQueryIncomingHttpHeaders extends IncomingHttpHeaders {
@@ -498,11 +493,11 @@ const certificateKeyFilePath = path.join(
 const certificateFilePath = path.join(proxyServerRoot, "cert-info/server.crt");
 
 // Get the port numbers to listen on
-const host = process.env.HOST || "localhost";
-const httpPort = process.env.PROXY_SERVER_HTTP_PORT || 80;
-const httpsPort = process.env.PROXY_SERVER_HTTPS_PORT || 443;
+const host = env.HOST;
+const httpPort = env.PROXY_SERVER_HTTP_PORT;
+const httpsPort = env.PROXY_SERVER_HTTPS_PORT;
 const useHttps =
-  process.env.PROXY_SERVER_HTTPS_CONNECTION === "true" &&
+  env.PROXY_SERVER_HTTPS_CONNECTION &&
   fs.existsSync(certificateKeyFilePath) &&
   fs.existsSync(certificateFilePath);