create a dockerized service for print_label_service.py

[tingox]

My attempt at fixing bitraf/bitraf-iot#19 Very much a work in progress. I have some questions:

• is there a way to use the necessary scripts and files from the bitraf-iot repository without including the whole repo into the docker container? (For now I just copied the necessary files from that repo, but that is not a very elegant solution, IMHO)
• how can I test this on another docker host than the default one? (say heim for example)

[tingox]

one question answered: the docker host is specified in the inventory file.

[mastensg]

how can I test this on another docker host than the default one? (say heim for example)

hvilken som helst maskin på bitraf lan med docker og docker-compose burde kunne teste dette med (kanskje først noe mer) docker-compose up i riktig katalog

[mastensg]

en feil jeg oppdaget på den måten:

$ docker-compose up
Building p2k16-label
Step 1/8 : FROM python:3.9-slim-bullseye
3.9-slim-bullseye: Pulling from library/python
7d63c13d9b9b: Pull complete

[...]

Successfully built be67bbbd9590
Successfully tagged p2k16-label:latest
WARNING: Image for service p2k16-label was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Creating templates_p2k16-label_1 ... done
Attaching to templates_p2k16-label_1
p2k16-label_1  | python: can't open file '/home/app_user/print_label_service.py': [Errno 13] Permission denied
templates_p2k16-label_1 exited with code 2

[mastensg]

$ docker run --rm -it label /bin/bash
app_user@c0cd2bb02940:~$ whoami
app_user
app_user@c0cd2bb02940:~$ ls -l /home/app_user/print_label_service.py 
-rwx------ 1 root root 2559 Nov  2 13:08 /home/app_user/print_label_service.py

[mastensg]

er det en spesiell grunn til at du ikke vil kjøre programmet som root inni kontaineren?

[trygvis]

I would suggest that the bitraf-iot repository takes care of producing the docker image and that this repository just installs that image. This would be similar to what we do with p2k16, postgresql and the other images.

The p2k16 repository has its own docker-compose.yml for local testing of the image. I see now that that docker-compose actually doesn't include a p2k16 service, but it could :).

[tingox]

er det en spesiell grunn til at du ikke vil kjøre programmet som root inni kontaineren?

ikke noe annet enn at det er "best practice" å kjøre som en annen bruker enn root.

[mastensg]

ok. jeg ser det er gjort sånn i p2k16 sin Dockerfile også, men riktig :)

https://github.com/bitraf/p2k16/blob/master/docker/Dockerfile

[mastensg]

(altså COPY --chown=p2k16 ...)

[trygvis]

Det riktige i dette tilfellet hadde vel bare vært chmod a+r. I p2k16 så kjøres pip install som p2k16 som peller på filene i imaget.

P2k16 skulle ideelt sett delt opp bygging og kjøring i to images, men jeg har ikke orket enda.

[tingox]

ok, this is now working, and ready for review. Fixes bitraf/bitraf-iot#19.

[tingox]

See also #125

[trygvis]

Looks good to me after a quick read!