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"
Related
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
How would I start a pm2 process with the —max-http-header-size node option, as well as name the process.
I have a server with multiple micro-services, one of the services is a web scraper.
This web scraper accepts requests with headers over the nodejs default 8kb limit. So, to run my app locally have to add the --max-http-header-size node option.
I've cloned my app to the server, but don't know how to set --max-http-header-size, nor do I know how to name the process within the pm2 start command.
So far my attempts have looked like this.
// this sets the name, but I don't know how to add the option `--max-http-header-size`
pm2 start npm --name "{REPONAME}" -- start
pm2 start node --name "scraper" --max-http-header-size 15000 app.js
pm2 start node --max-http-header-size 15000 app.js -- --name "scraper"
The accepted answer by David Harvey did not work for me as of Node 16. Instead, I had to use node_args, something like this:
{
"apps" : [{
"name" : "myapp",
"script" : "./app.js",
"node_args": "--max-http-header-size=256000",
"env": {
"NODE_ENV": "production",
}
}]
}
What you're looking for is called environment variables! You can pass environment variables to pm2 using a file that loads your server like this:
module.exports = {
apps : [
{
name: "myapp",
script: "./app.js",
watch: true,
node_args: "--max-http-header-size=16000"
}
]
}
Here's more about it too:
https://pm2.keymetrics.io/docs/usage/environment/
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
I am using pm2 to start my app but I'm not able to pass argument to it. The command I am using is pm2 start app.js -- dev. Though this works with forever.
If you want to pass node arguments from CLI then
pm2 start myServer.js --node-args="--production --port=1337"
.
Edited
you can add any arguments after --
pm2 start app.js -- --prod --second-arg --third-arg
Sails docs for deploymemt.
You can do as stated in this ticket: https://github.com/Unitech/pm2/issues/13
Though if you're passing the environment you may want to consider leveraging environment variables. With this you create a variable which can be accessed by any process in that environment with process.env.*.
So you have a configuration file config.json:
{
"dev": {
"db": {
"hosts":["localhost"],
"database": "api"
},
"redis": {
"hosts": ["localhost"]
}
},
"staging": {
"db": {
"hosts":["1.1.1.1"],
"database": "api"
},
"redis": {
"hosts": ["2.2.2.2"]
}
},
"production": {
"db": {
"hosts":["1.1.1.1", "1.1.1.2", "1.1.1.3"],
"database": "api"
},
"redis": {
"hosts": ["2.2.2.2", "2.2.2.3"]
}
}
}
Then you import your config:
var config=require('./config.json')[process.env.NODE_ENV || 'dev'];
db.connect(config.db.hosts, config.db.database);
Then you'd set the variable in your environment via shell:
export NODE_ENV=staging
pm2 start app.js
The environment variable will last as long as your session. So you'll have to set it in the ~/.bashrc file for that user for the variable to persist. This will set the variable every session.
PM2 has a deploy system which allows you to set an environment variable each time before your app is daemonized. This is how daemons in POSIX systems typically take parameters, because those parameters aren't lost with the process. Given with your circumstance it might not matter so much, but its a good practice.
Moreover you should consider stop/starting locally, and restarting(if in cluster mode) whenever possible to prevent downtime when in production.
It is possible to define arguments with the process.
You can define a new process in ecosystem.config.js with an args key, like so:
{
name : 'my-service',
script : './src/service.js',
args : 'firstArg secondArg',
},
{
name : 'my-service-alternate',
script : './src/service.js',
args : 'altFirstArg altSecondArg',
}
Here, the two processes use the same file (service.js), but pass different arguments to it.
Note that these arguments are handled within service.js.
In my case I just used process.argv[2] to get the first argument, and so on.
You can send arguments to your script by passing them after --. For example: pm2 start app.js -i max -- -a 23 // Pass arguments after -- to app.js
I have tested and it works in my windows machine. Below is the complete solution to pass arguments to nodejs app using pm2.
** There are also 2 types of argument
node-args - to use before npm start
args - to use in your node program
There are 2 ways to pass arguments with pm2.
Option 1: pass by argument with pm2 commands.
Option 2: by using config file e.g ecosystem.config.js
Option 1 (Pass arg by commands):
pm2 start app/myapp1.js --node-args="--max-http-header-size=80000" -- arg1 arg2
//Access the arg as below in your node program.
console.log(process.argv[2]); // arg1
console.log(process.argv[3]); // arg2
Option 2 (Using config file):
If you are using ecosystem.config.js. you can define with the following configuration:
{
name: 'my-app',
script: 'app\\myapp1.js',
env: {
NODE_ENV: 'DEV',
PORT : 5051
},
node_args: '--max-http-header-size=80000',
args : 'arg1 arg2',
instances: 1,
exec_mode: 'fork'
}
To start as dev mode:
pm2 start --name myapp app/myapp1.js -- .\ecosystem.config.js
To start as production mode, just add --env=production
pm2 start --name myapp app/myapp1.js -- .\ecosystem.config.js --env=production
//Access the arg as below in your node program.
console.log(process.argv[2]); // arg1
console.log(process.argv[3]); // arg2
I always use PM2 to run my python scripts in Linux environment. So consider a script has a single parameter and needs to run continously after some amount if time, then we can pass it like this:
pm2 start <filename.py> --name <nameForJob> --interpreter <InterpreterName> --restart-delay <timeinMilliseconds> -- <param1> <param2>
filename.py is Name of the python script, without <> symbols, I want to run using PM2
nameForJob is the Meaningful name for the job, without <> symbols
InterpreterName is the python interpreter for running script, usually it is python3 in linux
timeinMilliseconds is the time our script needs to wait and re-run again
param1 is the first parameter for the script
param2 is the second parameter for the script.
Well there are 2 ways you can do to pass the parameters from pm2 to nodejs in CLI:
pm2 start app.js -- dev --port=1234 (note there is an extra space between -- and dev)
pm2 start app.js --node-args="dev --port=1234"
Both ways, you will find these values exist in process.argv (['dev','--port=1234'])
You can pass args for node just like that:
NODE_TLS_REJECT_UNAUTHORIZED=0 NODE_ENV=dev pm2 start server.js --name web-server
I'll complement the answers above for npm scripts
For npm scripts
// package.json
{
"scripts": {
"start": "pm2 start --node-args=\"-r dotenv/config\" index.js"
}
}
npm run start runs pm2 start for index.js with node-args -r dotenv/config which include environment variables from .env file with dotenv
From the pm2 docs
//Inject what is declared in env_production
$ pm2 start app.js --env production
//Inject what is declared in env_staging
$ pm2 restart app.js --env staging
You need to start pm2 with something like:
pm2 start app.js --name "app_name" -- arg1 arg2
Then in your code, you can get your args with:
console.log(process.argv);
process.argv is a list like this:
[
'/usr/local/bin/node',
'/usr/local/lib/node_modules/pm2/lib/ProcessContainerFork.js',
'arg1',
'arg2'
]
A web app I am writing in JavaScript using node.js. I use Foreman, but I don't want to manually restart the server every time I change my code. Can I tell Foreman to reload the entire web app before handling an HTTP request (i.e. restart the node process)?
Here's an adjusted version of Pendlepants solution. Foreman looks for an .env file to read environment variables. Rather than adding a wrapper, you can just have Foreman switch what command it uses to start things up:
In .env:
WEB=node app.js
In dev.env:
WEB=supervisor app.js
In your Procfile:
web: $WEB
By default, Foreman will read from .env (in Production), but in DEV just run this:
foreman start -e dev.env
You can use rerun for this purpose
You might implement just 2 commands for this:
gem install rerun
rerun foreman start
Then rerun will automatically restart process after any change in your files.
If you use nodemon
, you can do
nodemon --exec "foreman start"
The problem isn't with Foreman so much as it's with how node doesn't reload code on new requests. The solution is to use an npm package like supervisor along with an environment wrapper for Foreman.
First, install supervisor:
npm install -g supervisor
Then, write a wrapper shell script that Foreman can call:
if [ "$NODE_ENV" == "production" ]; then
node /path/to/app.js
else
supervisor /path/to/app.js
fi
Set the wrapper script's permissions to executable by running chmod a+x /path/to/wrapper_script.sh
Lastly, update foreman to use the wrapper script. So in your Procfile:
web: /path/to/wrapper_script.sh
Now when you run Foreman and your node app isn't running in production, it should reload on every request.
I feel like Peter Ehrlich's comment on the original question deserves to be an answer on its own. I think a different Procfile for local/dev is definitely the best solution: https://stackoverflow.com/a/10790514/133720
You don't even need to install anything new if you use node-dev.
Your .env file loaded from Procfile:
NODECMD=node-dev
Your Procfile:
web: $NODECMD app/server.js
Your foreman command
foreman start -e dev.env -p 9786
And in your production env (heroku) set an environment variable:
NODECMD=node