Strapi Automatic Scaling on Google App Engine

Questions and Answers Strapi Backend
1
System Information
  • Strapi Version: 4.1.8
  • Operating System: OS X
  • Database: PostgreSQL
  • Node Version: 16.13.0
  • NPM Version: 8.1.0
  • Yarn Version: 1.22.17

Hi, everyone! I’m new to Strapi and Google App Engine. According to the app engine documentation, automatic scaling using min_idle_instances or min_instances elements is required to have a warmup request handler on the applications.

https://cloud.google.com/appengine/docs/standard/nodejs/configuring-warmup-requests

How to make a custom handler and route path to /_ah/warmup?
I’ve tried to make a custom plugin for this but turns out the custom plugin name must be in kebab case. Any other ideas? Thanks :smiley:

1 Like
2

It’s solved for now, but I don’t think this is the best approach. What I’ve done is create a custom middleware to check the ctx.path

 async (ctx, next) => {
    if (ctx.path !== '/_ah/warmup') return await next()

    // Handle warmup logic here

    ctx.status = 200;
    ctx.body = 'OK';
};
3

@abimnyud Did you find an alternate option for this? And if not is this solution still working for you?

I have tried your solution but it isn’t working for me. I end up in a redirect loop where App Engine just issues a series of 302 redirects back to the same page over and over until the browser steps in and errors with “The page isn’t redirecting properly”.

I am running Strapi as a microservice in my multi-service GCP project, it isn’t the default service so the routing is via the -dot- notation e.g. https://cms-dot-.appspot.com/_ah/warmup. Is this similar to what you are doing or are you running on the default service?

In my search I also came across this but can’t make that work either.

Any tips/pointers?

4

For anyone else reading this in future. The code the OP posted above does work just don’t expect to be able to access /_ah/warmup from your browser to check to see if it works.

Instead, depend on the GCP Logs. You can use protoPayload.wasLoadingRequest="true" as a log filter to see your cold start requests, as long as /_ah/warmup is returning 200 responses on there it kind of doesn’t matter if you can reach it from your browser or not.

I think the issue in the browser may be related to the HSTS header that Strapi sets for you by default. Either that or the secure: optional directive that is the default for app.yaml.

I had some success with altering my app.yaml to secure: never in order to see the warmup request in the browser but I don’t want to suggest that for anything other than dev work, certainly not production.

Changing it to secure:always and deploying again means I can’t see /_ah/warmup in my browser (I get that aforementioned redirect issue) but I do see it being successful in the GCP logs.

5

Just for completeness here is my typescript version of the OP’s handler.

import type { Strapi } from "@strapi/strapi";
import type { Context, Next } from "koa";

export default (
    config: Record<string, unknown>,
    { strapi }: { strapi: Strapi }
) => {
    return async (ctx: Context, next: Next) => {
        if (ctx.path === "/_ah/warmup") {
            ctx.send({ success: true }, 200);
        }
        await next();
    };
};
6

Thanks jgale for the solution. I added a file under /src/middlewares and then update /config/middleware.js but when google sends warm up requests they end up in redirect & look, what is the solution here do you know?

7

Please see my earlier posts above (#3 and #4).

I end up in a redirect loop where App Engine just issues a series of 302 redirects back to the same page over and over until the browser steps in and errors with “The page isn’t redirecting properly”.

…

just don’t expect to be able to access /_ah/warmup from your browser to check to see if it works.

Instead, depend on the GCP Logs. You can use protoPayload.wasLoadingRequest="true" as a log filter to see your cold start requests, as long as /_ah/warmup is returning 200 responses on there it kind of doesn’t matter if you can reach it from your browser or not.

8

You may also have to update config/env/production/middlewares.ts if you have different files for production.