# Accessing environment variables
**URL:** https://discourse.nodered.org/t/accessing-environment-variables/86388
**Category:** General
**Created:** [13 March 2024 03:00 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388 "2024-03-13T03:00:16Z")
**Posts on this page:** 17
**Page:** 1
### Author:  [@ThisEndUp](https://discourse.nodered.org/u/ThisEndUp)
#### Post date: [13 March 2024 03:00 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/1 "2024-03-13T03:00:17Z")
I'm trying to use an MQTT broker to broadcast some data.
For flexibility, I want to set the MQTT variables in the system environment and then read them
in my Node-Red flow. It used to work (some years ago) but no longer does. Here's a simple example
showing this.
Working context:
Node-RED version: v3.1.6
Node.js version: v18.19.1
Linux 6.1.0-rpi7-rpi-v8 arm64 LE
(1) Check that the environment variables are set:
`user@RP01:~$ set | grep MQTT`
which returns
> ```
> MQTT_BROKER=broker.hivemq.com
> MQTT_CLIENT_ID=Client007
> MQTT_NAME=MyName
> MQTT_PORT=1883
> MQTT_TOPIC=ViewMe/Meter01
>
> ```
(2) Based on what I found searching the Internet (and possibly not the right thing to do),
here's the (only) change I made to settings.js in the ~/.node-red directory:
```auto
functionGlobalContext: {
// os:require('os'),
env: process.env,
},
```
(3) Now start Node-Red
`user@RP01:~$ node-red-start`
which returns
```auto
Start Node-RED
...[snipped]...
Starting as a systemd service.
```
(4) Run the following flow in a browser.
Flow to display the MQTT variables:
```auto
[
{
"id": "98320a06c471a025",
"type": "tab",
"label": "Flow 3",
"disabled": false,
"info": "",
"env": []
},
{
"id": "179e115a0c5b7eae",
"type": "function",
"z": "98320a06c471a025",
"name": "View MQTT variables",
"func": "msg.payload = \"MQTT_BROKER: '\" + env.get('MQTT_BROKER') +\"' \\n\";\nmsg.payload = msg.payload + \"MQTT_PORT: '\" + env.get('MQTT_PORT') +\"' \\n\";\nmsg.payload = msg.payload + \"MQTT_TOPIC: '\" + env.get('MQTT_TOPIC') +\"' \\n\";\nmsg.payload = msg.payload + \"--- following are not used ---\" + \" \\n\";\nmsg.payload = msg.payload + \"MQTT_CLIENT_ID: '\"+ env.get('MQTT_CLIENT_ID') + \"' \\n\";\nmsg.payload = msg.payload + \"MQTT_NAME: '\" + env.get('MQTT_NAME') +\"' \\n\";\nreturn msg;\n",
"outputs": 1,
"timeout": "",
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 360,
"y": 80,
"wires": [
[
"3e6758c2883dfd69"
]
]
},
{
"id": "3e6758c2883dfd69",
"type": "debug",
"z": "98320a06c471a025",
"name": "",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "false",
"x": 570,
"y": 80,
"wires": []
},
{
"id": "f37e16fcb00b5f1a",
"type": "inject",
"z": "98320a06c471a025",
"name": "",
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "true",
"payloadType": "bool",
"x": 130,
"y": 80,
"wires": [
[
"179e115a0c5b7eae"
]
]
}
]
```
The result is
```auto
msg.payload : string[178]
"MQTT_BROKER: 'undefined' ↵MQTT_PORT: 'undefined' ↵MQTT_TOPIC: 'undefined' ↵--- following are not used --- ↵MQTT_CLIENT_ID: 'undefined' ↵MQTT_NAME: 'undefined' ↵"
```
I.e., everything is undefined.
Many thanks for help in figuring this out.
~ThisEndUp.
---
### Author:  [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [13 March 2024 03:44 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/2 "2024-03-13T03:44:09Z")
None of that is necessary. Just enter the parameters in the MQTT config node setup using this syntax `${ENVVAR}`.
it's all in the docs: [Using environment variables : Node-RED](https://nodered.org/docs/user-guide/environment-variables)
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [13 March 2024 14:11 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/3 "2024-03-13T14:11:03Z")
This might be helpfull, some stuff I only just discovered:
There are several ways to define environment variables for Node-red.
One approach (on Linux) is to declare them in a file `.node-red/EnvironmentFile` (the filename is specified in /etc/systemd/system/multi-user.target.wants/nodered.service") and restarting Node-red. eg:
```auto
WIBBLE="This variable set in .node-red/EnvironmentFile"
```
Accessing the environment variable - in an Inject node there are two options
Feeding that to a debug node gives
---
### Author:  [@ThisEndUp](https://discourse.nodered.org/u/ThisEndUp)
#### Post date: [16 March 2024 00:18 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/4 "2024-03-16T00:18:23Z")
My attempts are still failing. The variables are set in the shell immediately before starting node-red, as confirmed by the command `set | grep MQTT`. I then follow instructions in the [Using environment variables](https://nodered.org/docs/user-guide/environment-variables).
For example, those instructions state:
> Within a Function node, environment variables get be accessed using the `env.get` function:
>
> ```auto
> let foo = env.get("FOO");
>
> ```
But this is essentially what I posted. To follow the instructions more exactly, I changed it to
```auto
let broker = env.get("MQTT_BROKER");
msg.payload = "MQTT_BROKER: '" + broker + "' \n";
```
and the result is still `'MQTT_BROKER: 'undefined' `.
As for the suggestion that I define variables in a `.node-red/EnvironmentFile`, where this file is specified in a `nodered.service` file, there are no `node*` files at all in `/etc/systemd/system/multi-user.target.wants/`.
```auto
root@RP01:/etc/systemd/system/multi-user.target.wants# ls -l node*
ls: cannot access 'node*': No such file or directory
```
If I wanted to add a `nodered.service` file, what would it contain, and what would its format be? And would its name be `nodered.service` or `node-red.service` (with a hyphen)?
So, I'm still lost.
~ThisEndUp
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [16 March 2024 00:56 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/5 "2024-03-16T00:56:50Z")
OK my apologies, the Raspberry install script for Node-red does setup systemd but unless you run `sudo systemctl enable nodered` they are not accessible in that directory. Enabling makes a link so that Node-red is automatically started at boot. I always do this.
```auto
pi@zero2green:/etc/systemd/system/multi-user.target.wants $ ls -l nodered.service
lrwxrwxrwx 1 root root 35 Mar 15 00:14 nodered.service -> /lib/systemd/system/nodered.service
```
So the actual file is at /lib/systemd/system/nodered
ps I suspect that even with node-red auto start disabled, if you were to edit /lib/systemd/system/nodered.service and start Node-red with the node-red-start script, it would still use the systemd script. But I have never tried it.
pps It looks like you might be running Node-red as root? This is universally acknowledged to be a Bad Thing.
ppps You can also set environment variables in settings.js, eg this creates an environment variable HOSTNAME (I know, $HOSTNAME _should_ already exist)
```auto
// just above module.exports = {
hostname = require('os').hostname();
process.env.HOSTNAME = hostname;
```
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [16 March 2024 01:01 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/6 "2024-03-16T01:01:49Z")
> [@ThisEndUp](#):
>
> The variables are set in the shell immediately before starting node-red
Are you exporting the variables?
`EVERYTHING=42`
sets the variable, while
`export EVERYTHING=42`
makes it available in subshells
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [16 March 2024 07:41 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/7 "2024-03-16T07:41:11Z")
If you set an environment variable in a shell window it only affects processes run from that terminal. If you were to start node red using
`node-red`
Then it should be accessible in node red. However, by using node-red-start you are telling systemd to start node red, it is not running within your terminal window so the variable is not available.
You will have to define a system wide env var, or set it within the node red systemd script.
---
### Author:  [@ThisEndUp](https://discourse.nodered.org/u/ThisEndUp)
#### Post date: [16 March 2024 18:03 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/8 "2024-03-16T18:03:47Z")
Many thanks. I've found something that does work and some things that don't.
What does work:
I returned `~/.node-red/settings.js` to its original contents.
I followed jbudd's advice and ran `sudo systemctl enable nodered` and I created a file to set variables in `~/.node-red/EnvironmentFile`.
```auto
user@RP01:~$ cat ~/.node-red/EnvironmentFile
export MQTT_BROKER=broker.hivemq.com
export MQTT_PORT=1883
export MQTT_CLIENT_ID=Client007
export MQTT_TOPIC=ViewMe/Meter01
export MQTT_NAME=MyName
```
I rebooted the Raspberry Pi to make sure that node-red was started when the system comes up.
But see (1) below for the results of that (look for _on boot-up_).
I have a file named `~/startNR.sh` with contents:
```auto
#!/bin/sh
export MQTT_BROKER=broker.hivemq.com
export MQTT_PORT=1883
export MQTT_CLIENT_ID=Client007
export MQTT_TOPIC=ViewMe/Meter01
export MQTT_NAME=MyName
node-red-stop
node-red
```
When I run this, even asynchronously (i.e.,` ~/startNR.sh &`) , it stops node-red and then restarts it. As Colin suggested, this uses the command `node-red` and not `node-red-start`. Then the variables are defined and display properly. Hooray!
What does not work:
(1) setting variables in `~/.node-red/EnvironmentFile`.
And yes, there is a line
```auto
EnvironmentFile=-/home/user/.node-red/EnvironmentFile
```
in `/lib/systemd/system/nodered.service` which is linked as expected.
```auto
user@RP01:~$ ls -l /etc/systemd/system/multi-user.target.wants/nodered.service
lrwxrwxrwx 1 root root 35 Mar 16 12:06 /etc/systemd/system/multi-user.target.wants/nodered.service -> /lib/systemd/system/nodered.service
```
This has no effect, no matter when node-red is started, _on boot-up_, from a shell file, or directly from a command line. I don't understand this.
(2) Confirming Colin's comments, if I were to change `node-red` in the `startNR.sh` file to `node-red-start`, it does not work. Note that whenever the command `node-red-stop` runs, it advises `Use node-red-start to start Node-RED again`. This is not good advice if you want to set environment variables.
(3) Setting the ownership and permissions of ` ~/startNR.sh` -- e.g., to root with setuid -- doesn't help.
Again, thanks for the help.
ThisEndUp
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [16 March 2024 19:11 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/9 "2024-03-16T19:11:40Z")
> [@ThisEndUp](#):
>
> What does not work:
> (1) setting variables in `~/.node-red/`
That's a surprise because as I showed in my first post above, it works for me.
I don't have "export" in that file though, that's a bashism and I presume this file is interpreted by JavaScript.
Maybe it only works if node red autostart is enabled
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [16 March 2024 19:55 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/10 "2024-03-16T19:55:48Z")
What have you got in EnvironmentFile?
---
### Author:  [@ThisEndUp](https://discourse.nodered.org/u/ThisEndUp)
#### Post date: [16 March 2024 22:02 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/11 "2024-03-16T22:02:23Z")
It's listed in my response.
> [@ThisEndUp](#):
>
> ```auto
> user@RP01:~$ cat ~/.node-red/EnvironmentFile
> export MQTT_BROKER=broker.hivemq.com
> export MQTT_PORT=1883
> export MQTT_CLIENT_ID=Client007
> export MQTT_TOPIC=ViewMe/Meter01
> export MQTT_NAME=MyName
>
> ```
But I did try it once without the `export` at the beginning of the lines.
~ThisEndUp
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [16 March 2024 23:13 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/12 "2024-03-16T23:13:02Z")
If you will indulge me a little longer, please:
Edit your /home/user/node-red/EnvironmentFile to contain
```auto
MQTT_BROKER='broker.hivemq.com'
MQTT_PORT=1883
MQTT_CLIENT_ID=Client007
MQTT_TOPIC='ViewMe/Meter01'
MQTT_NAME='MyName'
```
Import this little flow
```auto
[{"id":"c0c11435666359ac","type":"inject","z":"2b90ab1f09978dc3","name":"","props":[{"p":"broker","v":"${MQTT_BROKER}","vt":"str"},{"p":"topic","v":"MQTT_TOPIC","vt":"env"},{"p":"port","v":"${MQTT_PORT}","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":170,"y":120,"wires":[["b15b20cf035d36f3"]]},{"id":"b15b20cf035d36f3","type":"debug","z":"2b90ab1f09978dc3","name":"From Environment","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":350,"y":120,"wires":[]}]
```
Stop Node-red
Start Node-red by either
```auto
sudo systemctl start nodered
```
or
```auto
sudo systemctl enable nodered
sudo reboot
```
Show us what the debug output is.
What I get, on a Raspberry running Node-red 4.0 is
---
### Author:  [@ThisEndUp](https://discourse.nodered.org/u/ThisEndUp)
#### Post date: [18 March 2024 20:51 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/13 "2024-03-18T20:51:13Z")
OK -- success. Here are the details:
(1) I've now modified the EnvironmentFile contents to remove `export` from the beginning of each line.
```auto
user@RP01:~$ cat ~/.node-red/EnvironmentFile
MQTT_BROKER=broker.hivemq.com
MQTT_PORT=1883
MQTT_CLIENT_ID=Client007
MQTT_TOPIC=ViewMe/Meter01
MQTT_NAME=MyName
```
(2) I've now got the following flow (the code files are in entries above, so I won't repeat them here).
(3) I make sure node red is not running:
```auto
user@RP01:~$ ps -ef | grep [Nn]ode
root 1264 1208 0 16:16 ? 00:00:00 fusermount3 -o rw,nosuid,nodev,fsname=portal,auto_unmount,subtype=portal -- /run/user/1000/doc
user@RP01:~$
```
(4) I then start node red with jbudd's recommended
```auto
sudo systemctl start nodered
```
I've also tried the alternative of rebooting the Raspberry Pi, and it works as well.
(5) The result is
```auto
3/18/2024, 4:23:29 PM
node: 3e6758c2883dfd69
msg.payload : string[183]
string[183]
MQTT_BROKER: 'broker.hivemq.com'
MQTT_PORT: '1883'
MQTT_TOPIC: 'ViewMe/Meter01'
--- following are not used ---
MQTT_CLIENT_ID: 'Client007'
MQTT_NAME: 'MyName'
3/18/2024, 4:23:31 PM
node: From Environment
ViewMe/Meter01 : msg : Object
object
_msgid: "15809db93a2e651b"
broker: "broker.hivemq.com"
topic: "ViewMe/Meter01"
port: "1883"
```
Hooray! The results are the desired ones, i.e.both the function named `View MQTT variables` which uses the `env.get()` function and the `inject` node, which uses TypedInput widgets, successfully access the environment variables in `~/.node-red/EnvironmentFile`.
Takeaway: The two essential changes were steps 1 and 4 above. Thank you jbudd for the actions that solved this and Colin for the explanation of the (IMHO subtle) reason that step 4 is necessary.
~ThisEndUp
---
### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [18 March 2024 21:41 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/14 "2024-03-18T21:41:56Z")
> [@ThisEndUp](#):
>
> I then start node red with jbudd's recommended
>
> ```auto
> sudo systemctl start nodered
>
> ```
Just to note that that is what
`node-red-start`
does.
---
### Author:  [@ThisEndUp](https://discourse.nodered.org/u/ThisEndUp)
#### Post date: [19 March 2024 16:33 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/15 "2024-03-19T16:33:56Z")
Thanks for the info.
I did try to test `node-red-start`. When that didn't work, I tried a subsequent `sudo systemctl start nodered`, and that did work. However, there are a number of moving parts -- most particularly `~/.node-red/EnvironmentFile` and open browser pages -- that were involved in all my tests. I tried to be careful, but it's quite possible that the tests that failed booted the Raspberry Pi when the environment file was not available, or that a browser page was stale.
In any case, I've tried `node-red-start` again in a three scenarios:
(1) with a reboot that started node-red automatically,
(2) after a reboot with an automatic start followed by a manual stop and then a start, and
(3) after a reboot after disabling node-red, so it didn't start automatically, followed by a manual start.
It worked each time. I've even tried it using
`bash -x node-red-start`
to see what it actually does, step-by-step. Indeed it does run `sudo systemctl start nodered`, so I don't really understand why it failed in my earlier tests.
I'm glad that the correct information is now out. Thanks again,
~ThisEndUp
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [19 March 2024 16:47 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/16 "2024-03-19T16:47:38Z")
> [@ThisEndUp](#):
>
> 'm glad that the correct information is now out.
Unfortunately the Node-red documentation on environment variables is wrong.
[https://discourse.nodered.org/t/error-in-user-guide/86486](https://discourse.nodered.org/t/error-in-user-guide/86486)
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [2 April 2024 16:48 UTC](https://discourse.nodered.org/t/accessing-environment-variables/86388/17 "2024-04-02T16:48:06Z")
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