Can't get $PORT value in dockerfile or startcommand
francois
HOBBYOP

2 years ago

I am trying to deploy a FastAPI app without success getting a socket.gaierror. I guess this is due to empty $PORT with dockerfile giving no exposed port.
I also tried to set the PORT value to 8000 without success.

I looked at the document without success.

It's my first time deploying from dockerfile. Any help is apreciated !

The build is done within dockerfile:
'''
…
WORKDIR /opt/
COPY . .
RUN echo "PORT: ${PORT}"
EXPOSE $PORT
''''

Build logs printing empty PORT value
'''

14 [10/10] RUN echo "PORT: ${PORT}"

14 0.325 PORT:

'''

Startcommand from railway.json:
'''
"startCommand": "hypercorn app:app --bind \"[::]:$PORT\"",
''''

Deployment logs error:
'''
insecuresockets = self.create_sockets(self.bind)
File "/usr/local/lib/python3.10/site-packages/hypercorn/config.py", line 266, in _create_sockets
sock.bind(binding)
socket.gaierror: [Errno -2] Name or service not known
'''

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Solved

4 Replies

francois
HOBBYOP

2 years ago

It seems the code formating is not good. Here is the logs with ` formating:

The build is done within dockerfile:

WORKDIR /opt/
COPY . .
RUN echo "PORT: ${PORT}"
EXPOSE $PORT

Build logs printing empty PORT value

#14 [10/10] RUN echo "PORT: ${PORT}"
#14 0.325 PORT:

Startcommand from railway.json:
"startCommand": "hypercorn app:app --bind \"[::]:$PORT\"",

Deployment logs error:

Traceback (most recent call last):
File "/usr/local/bin/hypercorn", line 8, in 
sys.exit(main())
File "/usr/local/lib/python3.10/site-packages/hypercorn/__main__.py", line 287, in main
run(config)
File "/usr/local/lib/python3.10/site-packages/hypercorn/run.py", line 38, in run
sockets = config.create_sockets()
File "/usr/local/lib/python3.10/site-packages/hypercorn/config.py", line 203, in create_sockets
insecure_sockets = self._create_sockets(self.bind)
File "/usr/local/lib/python3.10/site-packages/hypercorn/config.py", line 266, in _create_sockets
sock.bind(binding)
socket.gaierror: [Errno -2] Name or service not known
francois
HOBBYOP

2 years ago

Because I couldn't get the value of $PORT variable, even in the input start command filed from railway settings, I decided to hardcoded the port and it works fine.

brody
EMPLOYEE

2 years ago

The PORT variable is not available at build time, you should not use it anywhere in your Dockerfile besides in CMD (the command ran at runtime)

I would recommend omitting the startCommand in the railway.json and instead set CMD line to CMD hypercorn app:app --bind "[::]:$PORT"

Status changed to Solved Railway • almost 2 years ago

francois
HOBBYOP

2 years ago

Thank you for the anwser @brody.

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