Ensure that flask application will not crash the docker container when it encounters a syntax error

[carrollgt91]

Currently, when you save a python file on the server that causes a syntax error, it crashes the docker container, and you have to restart it. Ideally, it would continue trying to hot-reload the application without requiring you to restart the container.

server_1  |  * Debugger PIN: 128-930-505
server_1  | 172.20.0.1 - - [17/Mar/2020 17:16:16] "GET / HTTP/1.1" 200 -
server_1  | 172.20.0.1 - - [17/Mar/2020 17:23:40] "GET / HTTP/1.1" 200 -
server_1  |  * Detected change in '/server/run.py', reloading
server_1  |  * Restarting with stat
server_1  |  * Debugger is active!
server_1  |  * Debugger PIN: 128-930-505
server_1  |  * Detected change in '/server/run.py', reloading
server_1  |  * Restarting with stat
server_1  |   File "/server/run.py", line 6
server_1  |     if __name__ == "__main__"::
server_1  |                               ^
server_1  | SyntaxError: invalid syntax
private-identity-server_server_1 exited with code 1

[PlamenHristov]

Not really sure if this is the solution we are looking for, but if you add restart: always it will continuously try to restart the container, e.g.

version: '3'
services:
  server:
    image: openmined/pis:latest
    build: ./server/
    restart: always

[carrollgt91]

Ah, that's great! I don't think it's a 100% ideal solution, as it does delay before restarting as opposed to doing it "on-save" of a file, but it's better than not having it in place at all. Thanks!

[alejandrosame]

Hi!

I just pushed a PR proposing to use supervisor to target this issue. However, I wanted to document that if supervisor is not desired as a dependency for this case, it could still be possible to make a custom script like the official Docker documentation suggests: https://docs.docker.com/config/containers/multi-service_container/.