Unable to get environment variables

[akshaybabloo]

By default, Nginx Unit is not able to get the environment variables unless they are set through environment. Is there a way to get the environment variable from the system environment?

[i4ki]

@akshaybabloo What application language are you using?

if you use python, just import package "os".

import os

def application(environ, start_fn):
    start_fn('200 OK', [('Content-Type', 'text/plain')])
    return [os.environ["PATH"]]

same thing for Go, using os.Getenv(name) works.

[VBart]

Note that for PHP in order to have access to environment, the variables_order PHP configuration option set in php.ini (or via Unit configuration) must include E. See the PHP documentation for details: https://www.php.net/manual/en/ini.core.php#ini.variables-order

[akshaybabloo]

I am using Python and Django, when I use os.environ["PATH"] I get KeyError

[akshaybabloo]

Also, I am using PowerShell Core in Ubuntu 18.04

[i4ki]

I just installed PowerShell to test this, and it works here.

PS /vagrant/src/unit> ./build/unitd
2019/08/29 10:11:46.911 [info] 4811#4811 unit started
curl --unix-socket /home/vagrant/control.unit.sock -XPUT http://localhost/config/applications/helloworld2 --data-binary @app-python.json
{
	"success": "Reconfiguration done."
}
PS /vagrant/src/unit> curl --unix-socket /home/vagrant/control.unit.sock -XPUT 'http://localhost/config/listeners/*:8888' --data-binary '@listener.json'
{
	"success": "Reconfiguration done."
}
PS /vagrant/src/unit> curl localhost:8888        
/opt/microsoft/powershell/6:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/usr/local/go/bin

Try the following:

PS /vagrant/src/unit> python2
Python 2.7.15+ (default, Nov 27 2018, 23:36:35) 
[GCC 7.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.environ["PATH"]
'/opt/microsoft/powershell/6:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/usr/local/go/bin'
>>> 

If this doesn't works maybe it's something wrong on your setup.

[VBart]

@akshaybabloo How do you start unitd?

[akshaybabloo]

This is what I have in my docker file

unitd
touch /var/log/access.log
curl -X PUT --data-binary @nginx-unit-config.json --unix-socket /var/run/control.unit.sock http://localhost/config/
tail -f /var/log/access.log -f /var/log/unit.log

[VBart]

@akshaybabloo And where you have set the environment variables for the docker?

[akshaybabloo]

The above code is from Docker-Entrypoint.ps1 which looks like:

$Env:DANGO_SECRET_KEY = "<key>"

Import-Module ./Some-More-Keys.psm1  # This file has more $Env:Key="Value"

# ....

unitd
touch /var/log/access.log
curl -X PUT --data-binary @nginx-unit-config.json --unix-socket /var/run/control.unit.sock http://localhost/config/
tail -f /var/log/access.log -f /var/log/unit.log

[VBart]

@akshaybabloo Please make sure that you have access to these environment variables without Unit, e.g. by running a simple Python script instead of unitd.

[akshaybabloo]

I am able to. Before using Nginx Unit I was running gunicorn and I never had an issue with that

[dannmartens]

I have the same issue.

I am evaluating Nginx Unit as a replacement for Gunicorn as the WSGI server for a Flask application and from what I can observe it seems the system environment is not available (through Python's os API). The Flask application has been configured to exit, when required environment variables are not defined. As a result, configuring Nginx Unit fails immediately (with "error": "Failed to apply new configuration."). In the Unit logs, I see the Flask application balking at the missing environment variables.

We use the common pattern to convey configuration to the application through environment variables—in the end we run it as a Docker container with environment settings.

I haven't tried to Dockerize the app yet, but if setting the Unit config will be necessary as part of the build process, I don't see how this can work. A working config environment will only be available at the time we run the image.

[i4ki]

Hi @dannmartens

How are you trying to set the environment variables?

[i4ki]

Do you mean unitd is not having access to the environment variables set by docker?
Or are you trying to set the environment variables while unitd is running?