PM2 and Node: why am I getting env variable undefined? - node.js

Platform: Windows
What I want to do is simple: start pm2 (without any .json scripts) and have my node web app (ExpressJS) access the env. variable.
when I do set
> set MODE=test
and then do
> npm start
I can access process.env.MODE which gives me 'test' exactly as I wanted.
Now I can't seem to figure out how to do this in pm2. If I
> set MODE=test
and then do
pm2 start ./bin/www
I get process.env.MODE is undefined
I also tried
pm2 start ./bin/www -x -- --MODE=test
also tried
set MODE="test" & pm2 start ./bin/www
and
set MODE=test & pm2 start ./bin/www
Nothing seems to work. What am I doing wrong? What should I do instead?

On Windows SET sets an environment variable in the current CMD session. You may need to SET your environment variable in the same CMD session that you are running pm2 from.
Alternately, use SETX to set a permanent environment variable. You need to close and re-open and CMD sessions in order to make an environment variable set with SETX available in all CMD sessions.
refer: https://superuser.com/questions/916649/what-is-the-difference-between-setx-and-set-in-environment-variables-in-windows

Related

Run nextjs application in the background

I have an application built with nextJs and this application should work on a local server (Windows).
my customer told me that he needed this application to work in the background after searching I found that I needed to use a package called pm2 and when I used it gives me an error and I found that I needed to make some configurations for it and I can't found any helping resources, please help 💔
I found that to run nextJs application in the background you will need a custom configuration
you need to download the pm2 globally in your system
create a file with the name ecosystem.config.js in the root folder next to the package.json file
you need to put your config data in this file which would be something like this
module.exports = {
apps: [
{
name: "inventory_test",
script: "node_modules/next/dist/bin/next",
args: "start -p 3333", //running on port 3000
watch: false,
},
],
};
you should set the name as the name you want to see when you check
the list of pm2
the problem will be solved when you set the script as I did in the code above to be more precise the default run of pm2 is to go to the node js folder in the system and try to make start for the application using npm directly but this is the problem we need to make it use the node runner from the nextjs itself or something like this so we change the script as above
after that, we set the arguments that we should run after the npm and in my example is the arg start and choose the port for our application too
and now we make our config
NOTES
you should make build before you start the application
to run the project you will open the folder of the project in the terminal || cmd || cmder and run the command pm2 start ecosystem.config.js

node env value does not get changed with process manager command

I am writing NODE_ENV=production pm2 start app to run the node environment into production mode. But somehow when I extract the value with app.get('env') it gives me development value only. So what should be inserted to run node environment into production mode ?
By default we want that PM2 doesn’t change process environment while restarting or reloading. So, In order to change the ENV value of a process just stopping and starting won't work.
You have to either DELETE the process and start again(which I mainly do because when I change envs there are some major changes happening inside, so this method works for me)
pm2 delete app
NODE_ENV=prod pm2 start app
Or, From the Doc "If you want to update them [While restarting/reloading a process], you must use --update-env":
You want to inject a new environment variable to a process (for
example DEBUG): Use DEBUG=* pm2 reload myapp --update-env

How can I check if my pm2 app NODE_ENV is getting set?

So I just deployed a site with node and pm2 for the first time and I'm going back and doing some optimization and reading best practices, etc.
I read that you can get a lot of benefit by setting NODE_ENV=production.
I found this in the pm2 docs:
[process.json]
"env_production" : {
"NODE_ENV": "production"
}
...
$ pm2 start process.json --env production
So, I did it but I have no idea if it is working. While trying to figure out how to check it I learned to try:
$ node
> process.env.NODE_ENV
> undefined
So, that's not a good sign.. but, with my limited understanding of how the low level stuff works, I can guess that maybe pm2 launches each app as a separate node process? So maybe I'm not in the right process when I try to check it.
Also, I don't know if I have to make a new ~/.pm2/dump.pm2 file because maybe whenever that is maybe overriding the options I set? (because I used pm2 startup).
How do I check if my pm2 app's NODE_ENV is set?
To answer the actual question in the title:
Within your script, for me my Express app's app.js file, you can use process.env.NODE_ENV to get the current value of NODE_ENV and log that out if you want.
An even better way is to use PM2's Process Metrics module, aka pmx.
yarn add pmx
or
npm install pmx --save
then
const Probe = require('pmx').probe()
Probe.metric({
name : 'NODE_ENV',
value : function() {
return process.env.NODE_ENV
}
})
Now it will show up in calls to pm2 monit (bottom left).
To change your environment:
It is necessary that you kill and restart the process to change your environment.
$ pm2 kill && pm2 start pm2.json --env production
The following isn't good enough:
pm2 restart pm2.json --env production
You can also check your NODE_ENV via running pm2 show <yourServerName>. This will output info about your running server including node env.
In addition, you can check your environment variables via running pm2 env 0. This will show all the environment variables for the running node process.
Start it with npm by adding this to your package.json:
"scripts": {
"myScript": "NODE_ENV=production pm2 start server.js"
}
Then
npm start myScript
You can do it directly too, but this is easy to manage, automate wth crontab and is in your source control...
Your process.json file is incomplete. Try using something like this:
[process.json]
{
"name" : "MyApp",
"script" : "myapp.js",
"env_production" : {
"NODE_ENV": "production"
}
}
Then add logging into your code, preferably somwhere on startup:
console.log("NODE_ENV : ", process.env.NODE_ENV);
Now start the application:
pm2 start process.json --env production
Lastly watch app logs:
pm2 logs MyApp
This should do it.
May be at the start of your server script you can print the value of the environment variable and then check the PM2 logs. Use the following code to print your environment variable value:
console.log('process.env.NODE_ENV:', process.env.NODE_ENV);
And then use the following code to see the PM2 logs
pm2 logs app_name
Here app_name is your process name as indicated by the entry in the process.json file.
You can set Environment variable for pm2 specifically.
go to /etc/systemd/system/ location.
you can see a file named pm2-username.service
file. (eg: pm2-root.service ) you can directly add an Enviorment variable for pm2.
for me, it was LD_LIBRARY_PATH . so I added the line as below after the PATH variable.
Environment=PATH=/usr/local/lib......
Environment=LD_LIBRARY_PATH=/opt/oracle/instantclient_21_1
after that, you can restart or start the node application with update-env flag,
pm2 start yourapp --update-env
try pm2 env <app_name/id> also you can find NODE_ENV in pm2 show <app_name/id>
In your terminal just type:
echo NODE_ENV
it will print current selected environment variable

Passing environment variables to node.js using pm2

I am trying to pass some arguments to my Express application which is run by pm2. There wasn't any hint in their documentation to do so, but apparently it's possible to pass some EV to your node application like SOME_STUFF=xxx pm2 start app.js.
Note - after updating environment variables in your environment, you must do the following:
pm2 restart all --update-env
ask me how I know...
Edit: also look for a .env file in the node source directory...
It's actually possible and I'm pretty sure it was in PM2's documentation some time ago.
Anyways, that's what you need to do:
pm2 start app.js -- -some_stuff xxx
Basically, add -- and then you can add your own app parameters.
Managed to find the source, it was hidden quite well: http://pm2.keymetrics.io/docs/usage/quick-start/#42-ways-of-starting-processes
I was having issues passing parameters using pm2 start app.js -- -some_stuff xxx so I opted to do this instead: SOME_STUFF=xxx OTHER_STUFF=abc pm2 start app.js.
Then when I ran pm2 logs I was able to see that my app successfully started and that the environment variables were set correctly where as before I was seeing errors around these variables when I ran pm2 logs.
The environment variables don't always update unless you force them to.
SOME_STUFF=xxx pm2 start app.js --update-env
You should pass ENV in ecosystem.config.js
ecosystem.config.js (in the root)
module.exports = {
apps: [
{
name: "project-name",
exec_mode: "cluster",
instances: "1",
script: "./server/index.js", // your script
args: "start",
env: {
NODE_ENV: "production",
SOME_ENV: "some_value"...
},
},
],
};
In the console:
pm2 start ecosystem.config.js
There is information about configuration of ENV in PM2 official documentation
My node app (sveltekit build) starts in my ubuntu server when I use
node build/index.js
and includes enviroment variables
so with pm2 I found that my app starts with envs starting it:
pm2 "node build/index.js"

Node & Elastic Beanstalk: Set environment NODE_ENV=prod

I need to execute the following command for production environment:
NODE_ENV=production node app.js
I tried passing it as a command under Configueration:
I get the following error in the logs:
sh: NODE_ENV=prod node app.js: command not found
I also tried:
NODE_ENV=prod //
error: sh: NODE_ENV=prod: command not found
NODE_ENV=prod app.js //
error: sh: NODE_ENV=prod app.js: command not found
What's the best way to execute the following command when launching the app on ELB:
NODE_ENV=production node app.js
You don't need to set the node command manually. Elastic Beanstalk attempts to start app.js, then server.js, and then npm start in that order. You can set the value of NODE_ENV in the "Environment Properties" section under "Configuration".
As others have mentioned you can manually add them by going to Configuration -> Software -> Environment properties.
A second way to do this is to add a .ebextensions/environment.config file.
Add the directory .ebextensions at the root of your project.
Create the file environment.config within .ebextensions.
Add your environment configurations.
Example of environment.config:
option_settings:
- option_name: NODE_ENV
value: production
You need to use the "Environment Properties" Not the node command.
Key: NODE_ENV
Value: production
I would just set NODE_ENV in Environment Properties under the same configuration area. You can also set this in your .ebextensions config.

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