Integrating PM2 on Google Cloud app engine - node.js

I am trying to integrate PM2 to Google Cloud App Engine but I just couldn't work it around. I am using PM2 for my site's staging site and I am very impressed with it. I use Digital Ocean droplet for staging. I realized that Google Cloud App Engine is not that flexible.
This is my package.json:
"main": "server.js",
"scripts": {
"start": "NODE_ENV=production npm run server:prod",
"server:prod": "node server.js",
"server:stage": "NODE_ENV=stage pm2 start server.js --exp-backoff-restart-delay=100 -i max",
"dev": "nodemon server.js",
"gcp-deploy-stage": "gcloud app deploy app.backend.stage.yaml --project=xxxxx",
"gcp-deploy-prod": "gcloud app deploy app.backend.prod.yaml --project=xxxx -v=alpha-16"
},
When I set production script start as staging like this:
"server:prod":"pm2 start server.js --exp-backoff-restart-delay=100 -i max"
and deploy this Google Cloud App Engine normally crashes because there is no global PM2 installed via NPM to start PM2.
Is there anybody went through this and made it work? Or any piece of code or any documentation that could lead me to the right solution?
Or the only option is migrating this to Google Cloud Compute Engine?
Thank you for reading this and your help.

If you want to use any module, you're going to have to include it in your package.json. Have you tried running npm install --save-dev pm2, and then redeploying your site? My guess is, that's going to get you where you want to go.
All of that aside - this probably isn't a good idea :) pm2 does a lot to manage processes on the machine, specifically dealing with crashes. App Engine Flexible does a lot of this at the infrastructure layer, automatically looking at instance health. It uses docker under the hood, which has it's own restart strategy. And then on top of that, if the the docker retry strategy doesn't work, the Google Load Balancer kicks in and will start a new compute instance for you. It's entirely possible doing process level monitoring and restarting like this will work, I just want to make sure you understand everything else that's happening under the hood.
Curiosity killed the cat - why did you end up going with App Engine Flexible over App Engine Standard?

Related

Nodejs app on Google Cloud App Engine not starting

Good day,
my very basic Nodejs app is deployed on a Google Cloud App Engine instance is not starting. The app works locally, deployment with app deploy runs without error - and on the app instance the app runs successfully when started manually through Cloud shell (with >npm start).
However, as soon as the Cloud Shell is closed my app is dead. What am I missing? How do I start-up the app to run permanently?
The app consists of
bot4.js file,
npm dependencies
app.yaml
package.json
app.yaml:
runtime: nodejs8
handlers:
- url: /
script: auto
package.json:
{
"name": "blexplorer",
"version": "1.0.0",
"description": "",
"main": "bot4.js",
"scripts": {
"start": "node bot4.js"
},
"author": "oystersauce",
"license": "ISC",
"dependencies": {
"discord.js": "^11.4.2",
"request": "^2.88.0"
}
}
Again, the app is running fine when started through the Cloud Shell but no longer, as soon as the Cloud Shell is closed. Also, it's a super simple discord-bot - hence there is no front-end whatsoever.
EDIT:
this is how I thought I started the app manually - but what I did here is starting the app within the cloud shell and not on the app instance:
here is how I deploy the app:
From GAE perspective the cloud shell is simply a shell on a "local" development machine which just happens to be hosted in the cloud. The instance running the cloud shell has no special relationship with GAE whatsoever.
What you're doing when running npm start is not actually starting the GAE instance, you're just starting a "local" execution of your service, just like when you'd be doing the same on your local machine.
With your configuration GAE should start your app automatically as soon a request for it is received. On an app with a frontend just clicking on the link you circled in the snapshot would get you on it. Since yours doesn't have a frontend it would probably be just started, but you'd have to rely on the dashboard info and/or your app's logs to confirm it is running.

Is it possible to have Heroku Local run like nodemon?

I'm new to Heroku, a little bit less to NodeJS (and Nodemon).
I am now using heroku local to run my app in local (and be as close as possible to my prod environment) but I'd like to have my app rebuilt and restarted everytime I make a change in local (as with Nodemon for example).
Is there nay way to do this with heroku local?
Thanks!
Nicolas.
Old question, I know, but came up while I was searching for the same. There is an answer here: https://stackoverflow.com/a/46561121
This is what I have in my package.json:
"scripts": {
"start": "nodemon --exec 'heroku local' --signal SIGTERM"
}
For anybody coming across this post in search of a solution. As mentioned by nicolasdaudin in response to tom, you can add nodemon to the heroku Procfile (https://devcenter.heroku.com/articles/procfile):
web: nodemon index.js
Note that nodemon must be installed globally for this to work:
npm i -g nodemon
Then you should be able to run heroku locally as normal with nodemon watching for changes:
heroku local web

Running forever script from Google Cloud Platform App Engine startup script

I have edited the startup-script variable for one of my instances running on the Google Cloud Platform App Engine. I'd like it to call a forever script to make sure my node app is running. So I added:
cd /opt/bitnami/apps/myapp
forever start --workingDir /opt/bitnami/apps/myapp/ --sourceDir /opt
/bitnami/apps/myapp/ app.js
after the #!/bin/bash line (also tried without the cd as it's not really necessary based on my command). But once the vm is started, running a forever list doesn't list my forever task as having ever started. If I copy and paste that forever command into a gcloud terminal and run, the task shows up fine and my app starts no problem.
Am I not calling this correctly somehow within the bash script?
The simple answer is that GAE does this by default. No need for forever or PM2. There are certain health checks that GAE does on the Docker container holding your app, and if they do not pass the instance is automatically restarted
If you want granular control over these checks (called Legacy Health Checks) you can add this to your app.yaml file:
health_check:
enable_health_check: True
check_interval_sec: 5
timeout_sec: 4
unhealthy_threshold: 2
healthy_threshold: 2
There is also updated mechanisms (called Updated Health Checks) that are still in beta, but can be used instead
The proper way to start your nodejs app on appengine is to specify the "scripts" field in your package.json, as the documentation
Below is an example borrowed from this sample
"scripts": {
"start": "node ./bin/www",
"test": "cd ..; npm run t -- appengine/analytics/test/*.test.js"
},
If you however, are only interested in running a node script, and not interested in the features that come with Google app engine, then you may simply run it on a Google Compute Engine instance.

Multiple NodeJS Services/Modules on Google App Engine Flexible Environment

I'm struggling to figure out how to deploy multiple nodejs services on google app engine flexible.
I'm using multiple nodejs classes with firebase-queue to process my tasks.
Right now, i'm using my package.json to trigger starting everything at once.
However, this has become problematic. I would like to be able to push a change to one particular service/script without having to stop every other script.
My package.json currently looks like something like this:
"scripts": {
"task1": "node ./src/task1.js",
"task2": "node ./src/task2.js",
"start": "npm-run-all -p task1 task2"
}
I'm using different .yaml files to determine which build variant I want to push (Debug or Release) but am finding it hard to deploy each task individually. I found documentation on how to do so in python, but nothing on nodejs. Does anyone have any suggestions?
(Answering my own question, big thanks to Justin for helping)
I was specifically having issues dynamically changing the script to start in my package.json.
I found the package.json can access environment variables using '$'
package.json:
"scripts": {
"start": "node $SCRIPT_TO_RUN"
}
myService.yaml
runtime: nodejs
vm: true
api_version: 1
instance_class: B4
manual_scaling:
instances: 1
service: cart-monitor-dev
env_variables:
SCRIPT_TO_RUN: './src/mytask.js'
Then deploy using:
gcloud app deploy myService.yaml
This is exactly why App Engine services exist :) You can create a {serviceName}.yaml for each service you want to deploy. Then, call gcloud app deploy service.yaml for each one. That creates multiple services in the same app. For an example see:
https://github.com/JustinBeckwith/cloudcats
Hope this helps!

Run node server and webpack together using package.json

I have completed todo app by learning from this video:
Super MEAN Stack Tutorial: Angular, Node/Express, Webpack, MongoDB, SASS, Babel/ES6, Bootstrap
In that video at time 19:18 at this url it is taught that I should use the below two commands in seperate git-bash instances if I want to run it in windows using npm run dev:
node server
webpack-dev-server --progress --colors
But in Linux (or any other OS than windows) you can use this script:
"Scripts": {
"start": "NODE_PATH=$NODE_PATH:./src node server",
"dev": "npm start & webpack-dev-server --progress --colors"
}
So, Is there any way I can do the same in windows?
Also, In that tutorial I can see that port no. 3000 is assigned to node server, but due to using dev dependencies he runs the localhost:8080 in browser. You can see that here. After the tutorial finishes, I followed along and created that app. Now I would like to deploy it. So, I would first like to learn to run test my site in non-dev dependencies mode. i.e. when I type localhost:3000 in browser, my app should run successfully. So, can anybody explain the steps for that?
Update:
I am a newbie in node.js. I watched many videos on node and tried to learn something from that. In all the videos I see that I run node server on port no. 3000 and then I type localhost:3000 in my browser. Now lastly I watched video about mean stack in which he uses webpack. Now, I am confused. I think there are two servers running. first server is webpack's server and second server is node's server. Upto today I typed localhost:3000 in my browser because I mentioned that port 3000 will be used by node in my code. But now in the video he is running localhost:8080 in browser. It means webpack's server is used. Then what happened to node server. Why can't I just run localhost:3000? Also in the video it is explained that webpack is a dev dependency. So, I think after the app is completed and ready to be deployed, my project can be run on the node server (by making some changes to the code, I am not sure). Let's take an example. Now I don't want to deploy the app to a real server. I want the same app to run on my friend's pc. He is not a developer. So, he should not depend on webpack as webpack is a dev dependency. So, he should be able to run the app on node server instead of webpack's server. So, he should type localhost:3000 instead of localhost:8080. That's what I don't understand.
Let's break this down:
If you've defined this script:
"Scripts": {
"start": "NODE_PATH=$NODE_PATH:./src node server",
"dev": "npm start & webpack-dev-server --progress --colors"
}
... then this npm command: npm run dev
... actually invokes these two actions:
a) npm start & # Runs NPM in the background
b) webpack-dev-server --progress --colors # Concurrently runs webpack in the foreground
You can accomplish the same thing in many ways using Windows, starting with a simple .bat file like this:
EXAMPLE: RunDev.bat:
start npm start
webpack-dev-server --progress --colors
=======================================================================
STRONG SUGGESTION:
Please forget about watching videos for a few moments. Try a couple of "hello world" tutorials. More importantly, play with the actual code. Try changing things in the code, and see what happens.
Forget about webpack, at least for the moment.
Think of npm as a "build tool"; not as a way to run your application. At least for a moment.
Focus on "node". Write a "node application".
Part of your "node application" will require "ExpressJS" and "Jade" (now renamed "pug" - I'm still using "Jade"). Use npm to get your ExpressJS and Jade dependencies, but stay focussed on Node.
SUGGESTED TUTORIAL:
A Simple Website in Node.js, Ben Gourley
Be sure to:
a. Download the code
b. Work through the tutorial, using the downloaded code
Please post back (a new post) with any specific questions you might have as you work through the tutorial.

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