feat: add graceful shutdown and better deployment environment logic

src/server.ts

@@ -4,12 +4,13 @@ import { Hono } from "hono";
 import { serve } from "@hono/node-server";
 import { serveStatic } from "@hono/node-server/serve-static";
 
-import { env } from "./config/env.js";
 import { log } from "./config/logger.js";
 import { corsConfig } from "./config/cors.js";
 import { ratelimit } from "./config/ratelimit.js";
+import { execGracefulShutdown } from "./utils.js";
+import { DeploymentEnv, env, SERVERLESS_ENVIRONMENTS } from "./config/env.js";
 import { errorHandler, notFoundHandler } from "./config/errorHandler.js";
-import type { AniwatchAPIVariables } from "./config/variables.js";
+import type { ServerContext } from "./config/variables.js";
 
 import { hianimeRouter } from "./routes/hianime.js";
 import { logging } from "./middleware/logging.js";
@@ -20,22 +21,30 @@ import pkgJson from "../package.json" with { type: "json" };
 //
 const BASE_PATH = "/api/v2" as const;
 
-const app = new Hono<{ Variables: AniwatchAPIVariables }>();
+const app = new Hono<ServerContext>();
 
 app.use(logging);
 app.use(corsConfig);
 app.use(cacheControl);
 
-//
-// CAUTION: For personal deployments, "refrain" from having an env
-// named "ANIWATCH_API_HOSTNAME". You may face rate limitting
-// or other issues if you do.
-const ISNT_PERSONAL_DEPLOYMENT = Boolean(env.ANIWATCH_API_HOSTNAME);
-if (ISNT_PERSONAL_DEPLOYMENT) {
+/*
+    CAUTION: 
+    Having the "ANIWATCH_API_HOSTNAME" env will
+    enable rate limitting for the deployment.
+    WARNING:
+    If you are using any serverless environment, you must set the
+    "ANIWATCH_API_DEPLOYMENT_ENV" to that environment's name, 
+    otherwise you may face issues.
+*/
+const isPersonalDeployment = Boolean(env.ANIWATCH_API_HOSTNAME);
+if (isPersonalDeployment) {
     app.use(ratelimit);
 }
 
-app.use("/", serveStatic({ root: "public" }));
+if (env.ANIWATCH_API_DEPLOYMENT_ENV === DeploymentEnv.NODEJS) {
+    app.use("/", serveStatic({ root: "public" }));
+}
+
 app.get("/health", (c) => c.text("daijoubu", { status: 200 }));
 app.get("/v", async (c) =>
     c.text(
@@ -55,31 +64,72 @@ app.notFound(notFoundHandler);
 app.onError(errorHandler);
 
 //
-// NOTE: this env is "required" for vercel deployments
-if (!env.ANIWATCH_API_VERCEL_DEPLOYMENT) {
-    serve({
+(function () {
+    /*
+        NOTE:
+        "ANIWATCH_API_DEPLOYMENT_MODE" env must be set to
+        its supported name for serverless deployments
+        Eg: "vercel" for vercel deployments
+    */
+    if (SERVERLESS_ENVIRONMENTS.includes(env.ANIWATCH_API_DEPLOYMENT_ENV)) {
+        return;
+    }
+
+    const server = serve({
         port: env.ANIWATCH_API_PORT,
         fetch: app.fetch,
-    }).addListener("listening", () => {
+    }).addListener("listening", () =>
         log.info(
             `aniwatch-api RUNNING at http://localhost:${env.ANIWATCH_API_PORT}`
+        )
+    );
+
+    process.on("SIGINT", () => execGracefulShutdown(server));
+    process.on("SIGTERM", () => execGracefulShutdown(server));
+    process.on("uncaughtException", (err) => {
+        log.error(`Uncaught Exception: ${err.message}`);
+        execGracefulShutdown(server);
+    });
+    process.on("unhandledRejection", (reason, promise) => {
+        log.error(
+            `Unhandled Rejection at: ${promise}, reason: ${reason instanceof Error ? reason.message : reason}`
         );
+        execGracefulShutdown(server);
     });
 
-    // NOTE: remove the `if` block below for personal deployments
-    if (ISNT_PERSONAL_DEPLOYMENT) {
-        const interval = 9 * 60 * 1000; // 9mins
+    /*
+        CAUTION:
+        The `if` below block is for `render free deployments` only,
+        as their free tier has an approx 10 or 15 minute sleep time.
+        This is to keep the server awake and prevent it from sleeping.
+        You can enable the automatic health check by setting the
+        environment variables "ANIWATCH_API_HOSTNAME" to your deployment's hostname,
+        and "ANIWATCH_API_DEPLOYMENT_ENV" to "render" in your environment variables.
+        If you are not using render, you can remove the below `if` block.
+    */
+    if (
+        isPersonalDeployment &&
+        env.ANIWATCH_API_DEPLOYMENT_ENV === DeploymentEnv.RENDER
+    ) {
+        const INTERVAL_DELAY = 8 * 60 * 1000; // 8mins
+        const url = new URL(`https://${env.ANIWATCH_API_HOSTNAME}/health`);
 
         // don't sleep
         setInterval(() => {
-            log.info(
-                `aniwatch-api HEALTH_CHECK at ${new Date().toISOString()}`
-            );
             https
-                .get(`https://${env.ANIWATCH_API_HOSTNAME}/health`)
-                .on("error", (err) => log.error(err.message.trim()));
-        }, interval);
+                .get(url.href)
+                .on("response", () => {
+                    log.info(
+                        `aniwatch-api HEALTH_CHECK at ${new Date().toISOString()}`
+                    );
+                })
+                .on("error", (err) =>
+                    log.warn(
+                        `aniwatch-api HEALTH_CHECK failed; ${err.message.trim()}`
+                    )
+                );
+        }, INTERVAL_DELAY);
     }
-}
+})();
 
 export default app;